- 17 Aug, 2018 40 commits
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Pavel Tatashin authored
non-vmemmap sparse also allocated large contiguous chunk of memory, and if fails falls back to smaller allocations. Use the same functions to allocate buffer as the vmemmap-sparse Link: http://lkml.kernel.org/r/20180712203730.8703-3-pasha.tatashin@oracle.comSigned-off-by:
Pavel Tatashin <pasha.tatashin@oracle.com> Tested-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Reviewed-by:
Oscar Salvador <osalvador@suse.de> Tested-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Pavel Tatashin authored
Patch series "sparse_init rewrite", v6. In sparse_init() we allocate two large buffers to temporary hold usemap and memmap for the whole machine. However, we can avoid doing that if we changed sparse_init() to operated on per-node bases instead of doing it on the whole machine beforehand. As shown by Baoquan http://lkml.kernel.org/r/20180628062857.29658-1-bhe@redhat.com The buffers are large enough to cause machine stop to boot on small memory systems. Another benefit of these changes is that they also obsolete CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER. This patch (of 5): When struct pages are allocated for sparse-vmemmap VA layout, we first try to allocate one large buffer, and than if that fails allocate struct pages for each section as we go. The code that allocates buffer is uses global variables and is spread across several call sites. Cleanup the code by introducing three functions to handle the global buffer: sparse_buffer_init() initialize the buffer sparse_buffer_fini() free the remaining part of the buffer sparse_buffer_alloc() alloc from the buffer, and if buffer is empty return NULL Define these functions in sparse.c instead of sparse-vmemmap.c because later we will use them for non-vmemmap sparse allocations as well. [akpm@linux-foundation.org: use PTR_ALIGN()] [akpm@linux-foundation.org: s/BUG_ON/WARN_ON/] Link: http://lkml.kernel.org/r/20180712203730.8703-2-pasha.tatashin@oracle.comSigned-off-by:
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Cannon Matthews authored
When using 1GiB pages during early boot, use the new memblock_virt_alloc_try_nid_raw() to allocate memory without zeroing it. Zeroing out hundreds or thousands of GiB in a single core memset() call is very slow, and can make early boot last upwards of 20-30 minutes on multi TiB machines. The memory does not need to be zero'd as the hugetlb pages are always zero'd on page fault. Tested: Booted with ~3800 1G pages, and it booted successfully in roughly the same amount of time as with 0, as opposed to the 25+ minutes it would take before. Link: http://lkml.kernel.org/r/20180711213313.92481-1-cannonmatthews@google.comSigned-off-by:
Cannon Matthews <cannonmatthews@google.com> Acked-by:
Mike Kravetz <mike.kravetz@oracle.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: David Matlack <dmatlack@google.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by:
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Aaron Lu authored
To improve page allocator's performance for order-0 pages, each CPU has a Per-CPU-Pageset(PCP) per zone. Whenever an order-0 page is needed, PCP will be checked first before asking pages from Buddy. When PCP is used up, a batch of pages will be fetched from Buddy to improve performance and the size of batch can affect performance. zone's batch size gets doubled last time by commit ba56e91c("mm: page_alloc: increase size of per-cpu-pages") over ten years ago. Since then, CPU has envolved a lot and CPU's cache sizes also increased. Dave Hansen is concerned the current batch size doesn't fit well with modern hardware and suggested me to do two things: first, use a page allocator intensive benchmark, e.g. will-it-scale/page_fault1 to find out how performance changes with different batch sizes on various machines and then choose a new default batch size; second, see how this new batch size work with other workloads. In the first test, we saw performance gains on high-core-count systems and little to no effect on older systems with more modest core counts. In this phase's test data, two candidates: 63 and 127 are chosen. In the second step, ebizzy, oltp, kbuild, pigz, netperf, vm-scalability and more will-it-scale sub-tests are tested to see how these two candidates work with these workloads and decides a new default according to their results. Most test results are flat. will-it-scale/page_fault2 process mode has 10%-18% performance increase on 4-sockets Skylake and Broadwell. vm-scalability/lru-file-mmap-read has 17%-47% performance increase for 4-sockets servers while for 2-sockets servers, it caused 3%-8% performance drop. Further analysis showed that, with a larger pcp->batch and thus larger pcp->high(the relationship of pcp->high=6 * pcp->batch is maintained in this patch), zone lock contention shifted to LRU add side lock contention and that caused performance drop. This performance drop might be mitigated by others' work on optimizing LRU lock. Another downside of increasing pcp->batch is, when PCP is used up and need to fetch a batch of pages from Buddy, since batch is increased, that time can be longer than before. My understanding is, this doesn't affect slowpath where direct reclaim and compaction dominates. For fastpath, throughput is a win(according to will-it-scale/page_fault1) but worst latency can be larger now. Overall, I think double the batch size from 31 to 63 is relatively safe and provide good performance boost for high-core-count systems. The two phase's test results are listed below(all tests are done with THP disabled). Phase one(will-it-scale/page_fault1) test results: Skylake-EX: increased batch size has a good effect on zone->lock contention, though LRU contention will rise at the same time and limited the final performance increase. batch score change zone_contention lru_contention total_contention 31 15345900 +0.00% 64% 8% 72% 53 17903847 +16.67% 32% 38% 70% 63 17992886 +17.25% 24% 45% 69% 73 18022825 +17.44% 10% 61% 71% 119 18023401 +17.45% 4% 66% 70% 127 18029012 +17.48% 3% 66% 69% 137 18036075 +17.53% 4% 66% 70% 165 18035964 +17.53% 2% 67% 69% 188 18101105 +17.95% 2% 67% 69% 223 18130951 +18.15% 2% 67% 69% 255 18118898 +18.07% 2% 67% 69% 267 18101559 +17.96% 2% 67% 69% 299 18160468 +18.34% 2% 68% 70% 320 18139845 +18.21% 2% 67% 69% 393 18160869 +18.34% 2% 68% 70% 424 18170999 +18.41% 2% 68% 70% 458 18144868 +18.24% 2% 68% 70% 467 18142366 +18.22% 2% 68% 70% 498 18154549 +18.30% 1% 68% 69% 511 18134525 +18.17% 1% 69% 70% Broadwell-EX: similar pattern as Skylake-EX. batch score change zone_contention lru_contention total_contention 31 16703983 +0.00% 67% 7% 74% 53 18195393 +8.93% 43% 28% 71% 63 18288885 +9.49% 38% 33% 71% 73 18344329 +9.82% 35% 37% 72% 119 18535529 +10.96% 24% 46% 70% 127 18513596 +10.83% 23% 48% 71% 137 18514327 +10.84% 23% 48% 71% 165 18511840 +10.82% 22% 49% 71% 188 18593478 +11.31% 17% 53% 70% 223 18601667 +11.36% 17% 52% 69% 255 18774825 +12.40% 12% 58% 70% 267 18754781 +12.28% 9% 60% 69% 299 18892265 +13.10% 7% 63% 70% 320 18873812 +12.99% 8% 62% 70% 393 18891174 +13.09% 6% 64% 70% 424 18975108 +13.60% 6% 64% 70% 458 18932364 +13.34% 8% 62% 70% 467 18960891 +13.51% 5% 65% 70% 498 18944526 +13.41% 5% 64% 69% 511 18960839 +13.51% 5% 64% 69% Skylake-EP: although increased batch reduced zone->lock contention, but the effect is not as good as EX: zone->lock contention is still as high as 20% with a very high batch value instead of 1% on Skylake-EX or 5% on Broadwell-EX. Also, total_contention actually decreased with a higher batch but that doesn't translate to performance increase. batch score change zone_contention lru_contention total_contention 31 9554867 +0.00% 66% 3% 69% 53 9855486 +3.15% 63% 3% 66% 63 9980145 +4.45% 62% 4% 66% 73 10092774 +5.63% 62% 5% 67% 119 10310061 +7.90% 45% 19% 64% 127 10342019 +8.24% 42% 19% 61% 137 10358182 +8.41% 42% 21% 63% 165 10397060 +8.81% 37% 24% 61% 188 10341808 +8.24% 34% 26% 60% 223 10349135 +8.31% 31% 27% 58% 255 10327189 +8.08% 28% 29% 57% 267 10344204 +8.26% 27% 29% 56% 299 10325043 +8.06% 25% 30% 55% 320 10310325 +7.91% 25% 31% 56% 393 10293274 +7.73% 21% 31% 52% 424 10311099 +7.91% 21% 32% 53% 458 10321375 +8.02% 21% 32% 53% 467 10303881 +7.84% 21% 32% 53% 498 10332462 +8.14% 20% 33% 53% 511 10325016 +8.06% 20% 32% 52% Broadwell-EP: zone->lock and lru lock had an agreement to make sure performance doesn't increase and they successfully managed to keep total contention at 70%. batch score change zone_contention lru_contention total_contention 31 10121178 +0.00% 19% 50% 69% 53 10142366 +0.21% 6% 63% 69% 63 10117984 -0.03% 11% 58% 69% 73 10123330 +0.02% 7% 63% 70% 119 10108791 -0.12% 2% 67% 69% 127 10166074 +0.44% 3% 66% 69% 137 10141574 +0.20% 3% 66% 69% 165 10154499 +0.33% 2% 68% 70% 188 10124921 +0.04% 2% 67% 69% 223 10137399 +0.16% 2% 67% 69% 255 10143289 +0.22% 0% 68% 68% 267 10123535 +0.02% 1% 68% 69% 299 10140952 +0.20% 0% 68% 68% 320 10163170 +0.41% 0% 68% 68% 393 10000633 -1.19% 0% 69% 69% 424 10087998 -0.33% 0% 69% 69% 458 10187116 +0.65% 0% 69% 69% 467 10146790 +0.25% 0% 69% 69% 498 10197958 +0.76% 0% 69% 69% 511 10152326 +0.31% 0% 69% 69% Haswell-EP: similar to Broadwell-EP. batch score change zone_contention lru_contention total_contention 31 10442205 +0.00% 14% 48% 62% 53 10442255 +0.00% 5% 57% 62% 63 10452059 +0.09% 6% 57% 63% 73 10482349 +0.38% 5% 59% 64% 119 10454644 +0.12% 3% 60% 63% 127 10431514 -0.10% 3% 59% 62% 137 10423785 -0.18% 3% 60% 63% 165 10481216 +0.37% 2% 61% 63% 188 10448755 +0.06% 2% 61% 63% 223 10467144 +0.24% 2% 61% 63% 255 10480215 +0.36% 2% 61% 63% 267 10484279 +0.40% 2% 61% 63% 299 10466450 +0.23% 2% 61% 63% 320 10452578 +0.10% 2% 61% 63% 393 10499678 +0.55% 1% 62% 63% 424 10481454 +0.38% 1% 62% 63% 458 10473562 +0.30% 1% 62% 63% 467 10484269 +0.40% 0% 62% 62% 498 10505599 +0.61% 0% 62% 62% 511 10483395 +0.39% 0% 62% 62% Westmere-EP: contention is pretty small so not interesting. Note too high a batch value could hurt performance. batch score change zone_contention lru_contention total_contention 31 4831523 +0.00% 2% 3% 5% 53 4834086 +0.05% 2% 4% 6% 63 4834262 +0.06% 2% 3% 5% 73 48328518 +0.03% 2% 4% 6% 119 4830534 -0.02% 1% 3% 4% 127 4827461 -0.08% 1% 4% 5% 137 4827459 -0.08% 1% 3% 4% 165 4820534 -0.23% 0% 4% 4% 188 4817947 -0.28% 0% 3% 3% 223 4809671 -0.45% 0% 3% 3% 255 4802463 -0.60% 0% 4% 4% 267 4801634 -0.62% 0% 3% 3% 299 4798047 -0.69% 0% 3% 3% 320 4793084 -0.80% 0% 3% 3% 393 4785877 -0.94% 0% 3% 3% 424 4782911 -1.01% 0% 3% 3% 458 4779346 -1.08% 0% 3% 3% 467 4780306 -1.06% 0% 3% 3% 498 4780589 -1.05% 0% 3% 3% 511 4773724 -1.20% 0% 3% 3% Skylake-Desktop: similar to Westmere-EP, nothing interesting. batch score change zone_contention lru_contention total_contention 31 3906608 +0.00% 2% 3% 5% 53 3940164 +0.86% 2% 3% 5% 63 3937289 +0.79% 2% 3% 5% 73 3940201 +0.86% 2% 3% 5% 119 3933240 +0.68% 2% 3% 5% 127 3930514 +0.61% 2% 4% 6% 137 3938639 +0.82% 0% 3% 3% 165 3908755 +0.05% 0% 3% 3% 188 3905621 -0.03% 0% 3% 3% 223 3903015 -0.09% 0% 4% 4% 255 3889480 -0.44% 0% 3% 3% 267 3891669 -0.38% 0% 4% 4% 299 3898728 -0.20% 0% 4% 4% 320 3894547 -0.31% 0% 4% 4% 393 3875137 -0.81% 0% 4% 4% 424 3874521 -0.82% 0% 3% 3% 458 3880432 -0.67% 0% 4% 4% 467 3888715 -0.46% 0% 3% 3% 498 3888633 -0.46% 0% 4% 4% 511 3875305 -0.80% 0% 5% 5% Haswell-Desktop: zone->lock is pretty low as other desktops, though lru contention is higher than other desktops. batch score change zone_contention lru_contention total_contention 31 3511158 +0.00% 2% 5% 7% 53 3555445 +1.26% 2% 6% 8% 63 3561082 +1.42% 2% 6% 8% 73 3547218 +1.03% 2% 6% 8% 119 3571319 +1.71% 1% 7% 8% 127 3549375 +1.09% 0% 6% 6% 137 3560233 +1.40% 0% 6% 6% 165 3555176 +1.25% 2% 6% 8% 188 3551501 +1.15% 0% 8% 8% 223 3531462 +0.58% 0% 7% 7% 255 3570400 +1.69% 0% 7% 7% 267 3532235 +0.60% 1% 8% 9% 299 3562326 +1.46% 0% 6% 6% 320 3553569 +1.21% 0% 8% 8% 393 3539519 +0.81% 0% 7% 7% 424 3549271 +1.09% 0% 8% 8% 458 3528885 +0.50% 0% 8% 8% 467 3526554 +0.44% 0% 7% 7% 498 3525302 +0.40% 0% 9% 9% 511 3527556 +0.47% 0% 8% 8% Sandybridge-Desktop: the 0% contention isn't accurate but caused by dropped fractional part. Since multiple contention path's contentions are all under 1% here, with some arithmetic operations like add, the final deviation could be as large as 3%. batch score change zone_contention lru_contention total_contention 31 1744495 +0.00% 0% 0% 0% 53 1755341 +0.62% 0% 0% 0% 63 1758469 +0.80% 0% 0% 0% 73 1759626 +0.87% 0% 0% 0% 119 1770417 +1.49% 0% 0% 0% 127 1768252 +1.36% 0% 0% 0% 137 1767848 +1.34% 0% 0% 0% 165 1765088 +1.18% 0% 0% 0% 188 1766918 +1.29% 0% 0% 0% 223 1767866 +1.34% 0% 0% 0% 255 1768074 +1.35% 0% 0% 0% 267 1763187 +1.07% 0% 0% 0% 299 1765620 +1.21% 0% 0% 0% 320 1767603 +1.32% 0% 0% 0% 393 1764612 +1.15% 0% 0% 0% 424 1758476 +0.80% 0% 0% 0% 458 1758593 +0.81% 0% 0% 0% 467 1757915 +0.77% 0% 0% 0% 498 1753363 +0.51% 0% 0% 0% 511 1755548 +0.63% 0% 0% 0% Phase two test results: Note: all percent change is against base(batch=31). ebizzy.throughput (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 2410037±7% 2600451±2% +7.9% 2602878 +8.0% lkp-bdw-ex1 1493328 1489243 -0.3% 1492145 -0.1% lkp-skl-2sp2 1329674 1345891 +1.2% 1351056 +1.6% lkp-bdw-ep2 711511 711511 0.0% 710708 -0.1% lkp-wsm-ep2 75750 75528 -0.3% 75441 -0.4% lkp-skl-d01 264126 262791 -0.5% 264113 +0.0% lkp-hsw-d01 176601 176328 -0.2% 176368 -0.1% lkp-sb02 98937 98937 +0.0% 99030 +0.1% kbuild.buildtime (less is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 107.00 107.67 +0.6% 107.11 +0.1% lkp-bdw-ex1 97.33 97.33 +0.0% 97.42 +0.1% lkp-skl-2sp2 180.00 179.83 -0.1% 179.83 -0.1% lkp-bdw-ep2 178.17 179.17 +0.6% 177.50 -0.4% lkp-wsm-ep2 737.00 738.00 +0.1% 738.00 +0.1% lkp-skl-d01 642.00 653.00 +1.7% 653.00 +1.7% lkp-hsw-d01 1310.00 1316.00 +0.5% 1311.00 +0.1% netperf/TCP_STREAM.Throughput_total_Mbps (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 948790 947144 -0.2% 948333 -0.0% lkp-bdw-ex1 904224 904366 +0.0% 904926 +0.1% lkp-skl-2sp2 239731 239607 -0.1% 239565 -0.1% lk-bdw-ep2 365764 365933 +0.0% 365951 +0.1% lkp-wsm-ep2 93736 93803 +0.1% 93808 +0.1% lkp-skl-d01 77314 77303 -0.0% 77375 +0.1% lkp-hsw-d01 58617 60387 +3.0% 60208 +2.7% lkp-sb02 29990 30137 +0.5% 30103 +0.4% oltp.transactions (higer is better) machine batch=31 batch=63 batch=127 lkp-bdw-ex1 9073276 9100377 +0.3% 9036344 -0.4% lkp-skl-2sp2 8898717 8852054 -0.5% 8894459 -0.0% lkp-bdw-ep2 13426155 13384654 -0.3% 13333637 -0.7% lkp-hsw-ep2 13146314 13232784 +0.7% 13193163 +0.4% lkp-wsm-ep2 5035355 5019348 -0.3% 5033418 -0.0% lkp-skl-d01 418485 4413339 -0.1% 4419039 +0.0% lkp-hsw-d01 3517817±5% 3396120±3% -3.5% 3455138±3% -1.8% pigz.throughput (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1.513e+08 1.507e+08 -0.4% 1.511e+08 -0.2% lkp-bdw-ex1 2.060e+08 2.052e+08 -0.4% 2.044e+08 -0.8% lkp-skl-2sp2 8.836e+08 8.845e+08 +0.1% 8.836e+08 -0.0% lkp-bdw-ep2 8.275e+08 8.464e+08 +2.3% 8.330e+08 +0.7% lkp-wsm-ep2 2.224e+08 2.221e+08 -0.2% 2.218e+08 -0.3% lkp-skl-d01 1.177e+08 1.177e+08 -0.0% 1.176e+08 -0.1% lkp-hsw-d01 1.154e+08 1.154e+08 +0.1% 1.154e+08 -0.0% lkp-sb02 0.633e+08 0.633e+08 +0.1% 0.633e+08 +0.0% will-it-scale.malloc1.processes (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 620181 620484 +0.0% 620240 +0.0% lkp-bdw-ex1 1403610 1401201 -0.2% 1417900 +1.0% lkp-skl-2sp2 1288097 1284145 -0.3% 1283907 -0.3% lkp-bdw-ep2 1427879 1427675 -0.0% 1428266 +0.0% lkp-hsw-ep2 1362546 1353965 -0.6% 1354759 -0.6% lkp-wsm-ep2 2099657 2107576 +0.4% 2100226 +0.0% lkp-skl-d01 1476835 1476358 -0.0% 1474487 -0.2% lkp-hsw-d01 1308810 1303429 -0.4% 1301299 -0.6% lkp-sb02 589286 589284 -0.0% 588101 -0.2% will-it-scale.malloc1.threads (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 21289 21125 -0.8% 21241 -0.2% lkp-bdw-ex1 28114 28089 -0.1% 28007 -0.4% lkp-skl-2sp2 91866 91946 +0.1% 92723 +0.9% lkp-bdw-ep2 37637 37501 -0.4% 37317 -0.9% lkp-hsw-ep2 43673 43590 -0.2% 43754 +0.2% lkp-wsm-ep2 28577 28298 -1.0% 28545 -0.1% lkp-skl-d01 175277 173343 -1.1% 173082 -1.3% lkp-hsw-d01 130303 129566 -0.6% 129250 -0.8% lkp-sb02 113742±3% 116911 +2.8% 116417±3% +2.4% will-it-scale.malloc2.processes (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1.206e+09 1.206e+09 -0.0% 1.206e+09 +0.0% lkp-bdw-ex1 1.319e+09 1.319e+09 -0.0% 1.319e+09 +0.0% lkp-skl-2sp2 8.000e+08 8.021e+08 +0.3% 7.995e+08 -0.1% lkp-bdw-ep2 6.582e+08 6.634e+08 +0.8% 6.513e+08 -1.1% lkp-hsw-ep2 6.671e+08 6.669e+08 -0.0% 6.665e+08 -0.1% lkp-wsm-ep2 1.805e+08 1.806e+08 +0.0% 1.804e+08 -0.1% lkp-skl-d01 1.611e+08 1.611e+08 -0.0% 1.610e+08 -0.0% lkp-hsw-d01 1.333e+08 1.332e+08 -0.0% 1.332e+08 -0.0% lkp-sb02 82485104 82478206 -0.0% 82473546 -0.0% will-it-scale.malloc2.threads (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1.574e+09 1.574e+09 -0.0% 1.574e+09 -0.0% lkp-bdw-ex1 1.737e+09 1.737e+09 +0.0% 1.737e+09 -0.0% lkp-skl-2sp2 9.161e+08 9.162e+08 +0.0% 9.181e+08 +0.2% lkp-bdw-ep2 7.856e+08 8.015e+08 +2.0% 8.113e+08 +3.3% lkp-hsw-ep2 6.908e+08 6.904e+08 -0.1% 6.907e+08 -0.0% lkp-wsm-ep2 2.409e+08 2.409e+08 +0.0% 2.409e+08 -0.0% lkp-skl-d01 1.199e+08 1.199e+08 -0.0% 1.199e+08 -0.0% lkp-hsw-d01 1.029e+08 1.029e+08 -0.0% 1.029e+08 +0.0% lkp-sb02 68081213 68061423 -0.0% 68076037 -0.0% will-it-scale.page_fault2.processes (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 14509125±4% 16472364 +13.5% 17123117 +18.0% lkp-bdw-ex1 14736381 16196588 +9.9% 16364011 +11.0% lkp-skl-2sp2 6354925 6435444 +1.3% 6436644 +1.3% lkp-bdw-ep2 8749584 8834422 +1.0% 8827179 +0.9% lkp-hsw-ep2 8762591 8845920 +1.0% 8825697 +0.7% lkp-wsm-ep2 3036083 3030428 -0.2% 3021741 -0.5% lkp-skl-d01 2307834 2304731 -0.1% 2286142 -0.9% lkp-hsw-d01 1806237 1800786 -0.3% 1795943 -0.6% lkp-sb02 842616 837844 -0.6% 833921 -1.0% will-it-scale.page_fault2.threads machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1623294 1615132±2% -0.5% 1656777 +2.1% lkp-bdw-ex1 1995714 2025948 +1.5% 2113753±3% +5.9% lkp-skl-2sp2 2346708 2415591 +2.9% 2416919 +3.0% lkp-bdw-ep2 2342564 2344882 +0.1% 2300206 -1.8% lkp-hsw-ep2 1820658 1831681 +0.6% 1844057 +1.3% lkp-wsm-ep2 1725482 1733774 +0.5% 1740517 +0.9% lkp-skl-d01 1832833 1823628 -0.5% 1806489 -1.4% lkp-hsw-d01 1427913 1427287 -0.0% 1420226 -0.5% lkp-sb02 750626 748615 -0.3% 746621 -0.5% will-it-scale.page_fault3.processes (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 24382726 24400317 +0.1% 24668774 +1.2% lkp-bdw-ex1 35399750 35683124 +0.8% 35829492 +1.2% lkp-skl-2sp2 28136820 28068248 -0.2% 28147989 +0.0% lkp-bdw-ep2 37269077 37459490 +0.5% 37373073 +0.3% lkp-hsw-ep2 36224967 36114085 -0.3% 36104908 -0.3% lkp-wsm-ep2 16820457 16911005 +0.5% 16968596 +0.9% lkp-skl-d01 7721138 7725904 +0.1% 7756740 +0.5% lkp-hsw-d01 7611979 7650928 +0.5% 7651323 +0.5% lkp-sb02 3781546 3796502 +0.4% 3796827 +0.4% will-it-scale.page_fault3.threads (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1865820±3% 1900917±2% +1.9% 1826245±4% -2.1% lkp-bdw-ex1 3094060 3148326 +1.8% 3150036 +1.8% lkp-skl-2sp2 3952940 3953898 +0.0% 3989360 +0.9% lkp-bdw-ep2 3420373±3% 3643964 +6.5% 3644910±5% +6.6% lkp-hsw-ep2 2609635±2% 2582310±3% -1.0% 2780459 +6.5% lkp-wsm-ep2 4395001 4417196 +0.5% 4432499 +0.9% lkp-skl-d01 5363977 5400003 +0.7% 5411370 +0.9% lkp-hsw-d01 5274131 5311294 +0.7% 5319359 +0.9% lkp-sb02 2917314 2913004 -0.1% 2935286 +0.6% will-it-scale.read1.processes (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 73762279±14% 69322519±10% -6.0% 69349855±13% -6.0% (result unstable) lkp-bdw-ex1 1.701e+08 1.704e+08 +0.1% 1.705e+08 +0.2% lkp-skl-2sp2 63111570 63113953 +0.0% 63836573 +1.1% lkp-bdw-ep2 79247409 79424610 +0.2% 78012656 -1.6% lkp-hsw-ep2 67677026 68308800 +0.9% 67539106 -0.2% lkp-wsm-ep2 13339630 13939817 +4.5% 13766865 +3.2% lkp-skl-d01 10969487 10972650 +0.0% no data lkp-hsw-d01 9857342±2% 10080592±2% +2.3% 10131560 +2.8% lkp-sb02 5189076 5197473 +0.2% 5163253 -0.5% will-it-scale.read1.threads (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 62468045±12% 73666726±7% +17.9% 79553123±12% +27.4% (result unstable) lkp-bdw-ex1 1.62e+08 1.624e+08 +0.3% 1.614e+08 -0.3% lkp-skl-2sp2 58319780 59181032 +1.5% 59821353 +2.6% lkp-bdw-ep2 74057992 75698171 +2.2% 74990869 +1.3% lkp-hsw-ep2 63672959 63639652 -0.1% 64387051 +1.1% lkp-wsm-ep2 13489943 13526058 +0.3% 13259032 -1.7% lkp-skl-d01 10297906 10338796 +0.4% 10407328 +1.1% lkp-hsw-d01 9636721 9667376 +0.3% 9341147 -3.1% lkp-sb02 4801938 4804496 +0.1% 4802290 +0.0% will-it-scale.write1.processes (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1.111e+08 1.104e+08±2% -0.7% 1.122e+08±2% +1.0% lkp-bdw-ex1 1.392e+08 1.399e+08 +0.5% 1.397e+08 +0.4% lkp-skl-2sp2 59369233 58994841 -0.6% 58715168 -1.1% lkp-bdw-ep2 61820979 CPU throttle 63593123 +2.9% lkp-hsw-ep2 57897587 57435605 -0.8% 56347450 -2.7% lkp-wsm-ep2 7814203 7918017±2% +1.3% 7669068 -1.9% lkp-skl-d01 8886557 8971422 +1.0% 8818366 -0.8% lkp-hsw-d01 9171001±5% 9189915 +0.2% 9483909 +3.4% lkp-sb02 4475406 4475294 -0.0% 4501756 +0.6% will-it-scale.write1.threads (higer is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1.058e+08 1.055e+08±2% -0.2% 1.065e+08 +0.7% lkp-bdw-ex1 1.316e+08 1.300e+08 -1.2% 1.308e+08 -0.6% lkp-skl-2sp2 54492421 56086678 +2.9% 55975657 +2.7% lkp-bdw-ep2 59360449 59003957 -0.6% 58101262 -2.1% lkp-hsw-ep2 53346346±2% 52530876 -1.5% 52902487 -0.8% lkp-wsm-ep2 7774006 7800092±2% +0.3% 7558833 -2.8% lkp-skl-d01 8346174 8235695 -1.3% no data lkp-hsw-d01 8636244 8655731 +0.2% 8658868 +0.3% lkp-sb02 4181820 4204107 +0.5% 4182992 +0.0% vm-scalability.anon-r-rand.throughput (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 11933873±3% 12356544±2% +3.5% 12188624 +2.1% lkp-bdw-ex1 7114424±2% 7330949±2% +3.0% 7392419 +3.9% lkp-skl-2sp2 6773277±5% 6492332±8% -4.1% 6543962 -3.4% lkp-bdw-ep2 7133846±4% 7233508 +1.4% 7013518±3% -1.7% lkp-hsw-ep2 4576626 4527098 -1.1% 4551679 -0.5% lkp-wsm-ep2 2583599 2592492 +0.3% 2588039 +0.2% lkp-hsw-d01 998199±2% 1028311 +3.0% 1006460±2% +0.8% lkp-sb02 570572 567854 -0.5% 568449 -0.4% vm-scalability.anon-r-rand-mt.throughput (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1789419 1787830 -0.1% 1788208 -0.1% lkp-bdw-ex1 3492595±2% 3554966±2% +1.8% 3558835±3% +1.9% lkp-skl-2sp2 3856238±2% 3975403±4% +3.1% 3994600 +3.6% lkp-bdw-ep2 3726963±11% 3809292±6% +2.2% 3871924±4% +3.9% lkp-hsw-ep2 2131760±3% 2033578±4% -4.6% 2130727±6% -0.0% lkp-wsm-ep2 2369731 2368384 -0.1% 2370252 +0.0% lkp-skl-d01 1207128 1206220 -0.1% 1205801 -0.1% lkp-hsw-d01 964317 992329±2% +2.9% 992099±2% +2.9% lkp-sb02 567137 567346 +0.0% 566144 -0.2% vm-scalability.lru-file-mmap-read.throughput (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 19560469±6% 23018999 +17.7% 23418800 +19.7% lkp-bdw-ex1 17769135±14% 26141676±3% +47.1% 26284723±5% +47.9% lkp-skl-2sp2 14056512 13578884 -3.4% 13146214 -6.5% lkp-bdw-ep2 15336542 14737654 -3.9% 14088159 -8.1% lkp-hsw-ep2 16275498 15756296 -3.2% 15018090 -7.7% lkp-wsm-ep2 11272160 11237231 -0.3% 11310047 +0.3% lkp-skl-d01 7322119 7324569 +0.0% 7184148 -1.9% lkp-hsw-d01 6449234 6404542 -0.7% 6356141 -1.4% lkp-sb02 3517943 3520668 +0.1% 3527309 +0.3% vm-scalability.lru-file-mmap-read-rand.throughput (higher is better) machine batch=31 batch=63 batch=127 lkp-skl-4sp1 1689052 1697553 +0.5% 1698726 +0.6% lkp-bdw-ex1 1675246 1699764 +1.5% 1712226 +2.2% lkp-skl-2sp2 1800533 1799749 -0.0% 1800581 +0.0% lkp-bdw-ep2 1807422 1807758 +0.0% 1804932 -0.1% lkp-hsw-ep2 1809807 1808781 -0.1% 1807811 -0.1% lkp-wsm-ep2 1800198 1802434 +0.1% 1801236 +0.1% lkp-skl-d01 696689 695537 -0.2% 694106 -0.4% lkp-hsw-d01 698364 698666 +0.0% 696686 -0.2% lkp-sb02 258939 258787 -0.1% 258199 -0.3% Link: http://lkml.kernel.org/r/20180711055855.29072-1-aaron.lu@intel.comSigned-off-by:
Aaron Lu <aaron.lu@intel.com> Suggested-by:
Dave Hansen <dave.hansen@intel.com> Acked-by:
Jesper Dangaard Brouer <brouer@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Kemi Wang <kemi.wang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by:
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Michal Hocko authored
Add comments describing oom_lock's scope. Requested-by:
David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/20180711120121.25635-1-mhocko@kernel.orgSigned-off-by:
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Mike Kravetz authored
This reverts ee8f248d ("hugetlb: add phys addr to struct huge_bootmem_page"). At one time powerpc used this field and supporting code. However that was removed with commit 79cc38de ("powerpc/mm/hugetlb: Add support for reserving gigantic huge pages via kernel command line"). There are no users of this field and supporting code, so remove it. Link: http://lkml.kernel.org/r/20180711195913.1294-1-mike.kravetz@oracle.comSigned-off-by:
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Michal Hocko authored
Tetsuo has pointed out that since 27ae357f ("mm, oom: fix concurrent munlock and oom reaper unmap, v3") we have a strong synchronization between the oom_killer and victim's exiting because both have to take the oom_lock. Therefore the original heuristic to sleep for a short time in out_of_memory doesn't serve the original purpose. Moreover Tetsuo has noticed that the short sleep can be more harmful than actually useful. Hammering the system with many processes can lead to a starvation when the task holding the oom_lock can block for a long time (minutes) and block any further progress because the oom_reaper depends on the oom_lock as well. Drop the short sleep from out_of_memory when we hold the lock. Keep the sleep when the trylock fails to throttle the concurrent OOM paths a bit. This should be solved in a more reasonable way (e.g. sleep proportional to the time spent in the active reclaiming etc.) but this is much more complex thing to achieve. This is a quick fixup to remove a stale code. Link: http://lkml.kernel.org/r/20180709074706.30635-1-mhocko@kernel.orgSigned-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by:
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Marek Szyprowski authored
The CMA memory allocator doesn't support standard gfp flags for memory allocation, so there is no point having it as a parameter for dma_alloc_from_contiguous() function. Replace it by a boolean no_warn argument, which covers all the underlaying cma_alloc() function supports. This will help to avoid giving false feeling that this function supports standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer, what has already been an issue: see commit dd65a941 ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag"). Link: http://lkml.kernel.org/r/20180709122020eucas1p21a71b092975cb4a3b9954ffc63f699d1~-sqUFoa-h2939329393eucas1p2Y@eucas1p2.samsung.comSigned-off-by:
Marek Szyprowski <m.szyprowski@samsung.com> Acked-by:
Michał Nazarewicz <mina86@mina86.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Christoph Hellwig <hch@lst.de> Cc: Laura Abbott <labbott@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by:
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Marek Szyprowski authored
cma_alloc() doesn't really support gfp flags other than __GFP_NOWARN, so convert gfp_mask parameter to boolean no_warn parameter. This will help to avoid giving false feeling that this function supports standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer, what has already been an issue: see commit dd65a941 ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag"). Link: http://lkml.kernel.org/r/20180709122019eucas1p2340da484acfcc932537e6014f4fd2c29~-sqTPJKij2939229392eucas1p2j@eucas1p2.samsung.comSigned-off-by:
Laura Abbott <labbott@redhat.com> Acked-by:
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Rik van Riel authored
There was a bug in Linux that could cause madvise (and mprotect?) system calls to return to userspace without the TLB having been flushed for all the pages involved. This could happen when multiple threads of a process made simultaneous madvise and/or mprotect calls. This was noticed in the summer of 2017, at which time two solutions were created: 56236a59 ("mm: refactor TLB gathering API") 99baac21 ("mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem") and 4647706e ("mm: always flush VMA ranges affected by zap_page_range") We need only one of these solutions, and the former appears to be a little more efficient than the latter, so revert that one. This reverts 4647706e ("mm: always flush VMA ranges affected by zap_page_range") Link: http://lkml.kernel.org/r/20180706131019.51e3a5f0@imladris.surriel.comSigned-off-by:
Rik van Riel <riel@surriel.com> Acked-by:
Mel Gorman <mgorman@techsingularity.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by:
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Baoquan He authored
In sparse_init(), two temporary pointer arrays, usemap_map and map_map are allocated with the size of NR_MEM_SECTIONS. They are used to store each memory section's usemap and mem map if marked as present. With the help of these two arrays, continuous memory chunk is allocated for usemap and memmap for memory sections on one node. This avoids too many memory fragmentations. Like below diagram, '1' indicates the present memory section, '0' means absent one. The number 'n' could be much smaller than NR_MEM_SECTIONS on most of systems. |1|1|1|1|0|0|0|0|1|1|0|0|...|1|0||1|0|...|1||0|1|...|0| ------------------------------------------------------- 0 1 2 3 4 5 i i+1 n-1 n If we fail to populate the page tables to map one section's memmap, its ->section_mem_map will be cleared finally to indicate that it's not present. After use, these two arrays will be released at the end of sparse_init(). In 4-level paging mode, each array costs 4M which can be ignorable. While in 5-level paging, they costs 256M each, 512M altogether. Kdump kernel Usually only reserves very few memory, e.g 256M. So, even thouth they are temporarily allocated, still not acceptable. In fact, there's no need to allocate them with the size of NR_MEM_SECTIONS. Since the ->section_mem_map clearing has been deferred to the last, the number of present memory sections are kept the same during sparse_init() until we finally clear out the memory section's ->section_mem_map if its usemap or memmap is not correctly handled. Thus in the middle whenever for_each_present_section_nr() loop is taken, the i-th present memory section is always the same one. Here only allocate usemap_map and map_map with the size of 'nr_present_sections'. For the i-th present memory section, install its usemap and memmap to usemap_map[i] and mam_map[i] during allocation. Then in the last for_each_present_section_nr() loop which clears the failed memory section's ->section_mem_map, fetch usemap and memmap from usemap_map[] and map_map[] array and set them into mem_section[] accordingly. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20180628062857.29658-5-bhe@redhat.comSigned-off-by:
Baoquan He <bhe@redhat.com> Reviewed-by:
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Baoquan He authored
It's used to pass the size of map data unit into alloc_usemap_and_memmap, and is preparation for next patch. Link: http://lkml.kernel.org/r/20180228032657.32385-4-bhe@redhat.comSigned-off-by:
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Baoquan He authored
In sparse_init(), if CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER=y, system will allocate one continuous memory chunk for mem maps on one node and populate the relevant page tables to map memory section one by one. If fail to populate for a certain mem section, print warning and its ->section_mem_map will be cleared to cancel the marking of being present. Like this, the number of mem sections marked as present could become less during sparse_init() execution. Here just defer the ms->section_mem_map clearing if failed to populate its page tables until the last for_each_present_section_nr() loop. This is in preparation for later optimizing the mem map allocation. [akpm@linux-foundation.org: remove now-unused local `ms', per Oscar] Link: http://lkml.kernel.org/r/20180228032657.32385-3-bhe@redhat.comSigned-off-by:
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Baoquan He authored
Patch series "mm/sparse: Optimize memmap allocation during sparse_init()", v6. In sparse_init(), two temporary pointer arrays, usemap_map and map_map are allocated with the size of NR_MEM_SECTIONS. They are used to store each memory section's usemap and mem map if marked as present. In 5-level paging mode, this will cost 512M memory though they will be released at the end of sparse_init(). System with few memory, like kdump kernel which usually only has about 256M, will fail to boot because of allocation failure if CONFIG_X86_5LEVEL=y. In this patchset, optimize the memmap allocation code to only use usemap_map and map_map with the size of nr_present_sections. This makes kdump kernel boot up with normal crashkernel='' setting when CONFIG_X86_5LEVEL=y. This patch (of 5): nr_present_sections is used to record how many memory sections are marked as present during system boot up, and will be used in the later patch. Link: http://lkml.kernel.org/r/20180228032657.32385-2-bhe@redhat.comSigned-off-by:
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Kirill Tkhai authored
The patch introduces a special value SHRINKER_REGISTERING to use instead of list_empty() to differ a registering shrinker from unregistered shrinker. Why we need that at all? Shrinker registration is split in two parts. The first one is prealloc_shrinker(), which allocates shrinker memory and reserves ID in shrinker_idr. This function can fail. The second is register_shrinker_prepared(), and it finalizes the registration. This function actually makes shrinker available to be used from shrink_slab(), and it can't fail. One shrinker may be based on more then one LRU lists. So, we never clear the bit in memcg shrinker maps, when (one of) corresponding LRU list becomes empty, since other LRU lists may be not empty. See superblock shrinker for example: it is based on two LRU lists: s_inode_lru and s_dentry_lru. We do not want to clear shrinker bit, when there are no inodes in s_inode_lru, as s_dentry_lru may contain dentries. Instead of that, we use special algorithm to detect shrinkers having no elements at all its LRU lists, and this is made in shrink_slab_memcg(). See the comment in this function for the details. Also, in shrink_slab_memcg() we clear shrinker bit in the map, when we meet unregistered shrinker (bit is set, while there is no a shrinker in IDR). Otherwise, we would have done that at the moment of shrinker unregistration for all memcgs (and this looks worse, since iteration over all memcg may take much time). Also this would have imposed restrictions on shrinker unregistration order for its users: they would have had to guarantee, there are no new elements after unregister_shrinker() (otherwise, a new added element would have set a bit). So, if we meet a set bit in map and no shrinker in IDR when we're iterating over the map in shrink_slab_memcg(), this means the corresponding shrinker is unregistered, and we must clear the bit. Another case is shrinker registration. We want two things there: 1) do_shrink_slab() can be called only for completely registered shrinkers; 2) shrinker internal lists may be populated in any order with register_shrinker_prepared() (let's talk on the example with sb). Both of: a)list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru); [cpu0] memcg_set_shrinker_bit(); [cpu0] ... register_shrinker_prepared(); [cpu1] and b)register_shrinker_prepared(); [cpu0] ... list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru); [cpu1] memcg_set_shrinker_bit(); [cpu1] are legitimate. We don't want to impose restriction here and to force people to use only (b) variant. We don't want to force people to care, there is no elements in LRU lists before the shrinker is completely registered. Internal users of LRU lists and shrinker code are two different subsystems, and they have to be closed in themselves each other. In (a) case we have the bit set before shrinker is completely registered. We don't want do_shrink_slab() is called at this moment, so we have to detect such the registering shrinkers. Before this patch list_empty() (shrinker is not linked to the list) check was used for that. So, in (a) there could be a bit set, but we don't call do_shrink_slab() unless shrinker is linked to the list. It's just an indicator, I just overloaded linking to the list. This was not the best solution, since it's better not to touch the shrinker memory from shrink_slab_memcg() before it's completely registered (this also will be useful in the future to make shrink_slab() completely lockless). So, this patch introduces better way to detect registering shrinker, which allows not to dereference shrinker memory. It's just a ~0UL value, which we insert into the IDR during ID allocation. After shrinker is ready to be used, we insert actual shrinker pointer in the IDR, and it becomes available to shrink_slab_memcg(). We can't use NULL instead of this new value for this purpose as: shrink_slab_memcg() already uses NULL to detect unregistered shrinkers, and we don't want the function sees NULL and clears the bit, otherwise (a) won't work. This is the only thing the patch makes: the better way to detect registering shrinker. Nothing else this patch makes. Also this gives a better assembler, but it's minor side of the patch: Before: callq <idr_find> mov %rax,%r15 test %rax,%rax je <shrink_slab_memcg+0x1d5> mov 0x20(%rax),%rax lea 0x20(%r15),%rdx cmp %rax,%rdx je <shrink_slab_memcg+0xbd> mov 0x8(%rsp),%edx mov %r15,%rsi lea 0x10(%rsp),%rdi callq <do_shrink_slab> After: callq <idr_find> mov %rax,%r15 lea -0x1(%rax),%rax cmp $0xfffffffffffffffd,%rax ja <shrink_slab_memcg+0x1cd> mov 0x8(%rsp),%edx mov %r15,%rsi lea 0x10(%rsp),%rdi callq ffffffff810cefd0 <do_shrink_slab> [ktkhai@virtuozzo.com: add #ifdef CONFIG_MEMCG_KMEM around idr_replace()] Link: http://lkml.kernel.org/r/758b8fec-7573-47eb-b26a-7b2847ae7b8c@virtuozzo.com Link: http://lkml.kernel.org/r/153355467546.11522.4518015068123480218.stgit@localhost.localdomainSigned-off-by:Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by:
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Kirill Tkhai authored
In case of shrink_slab_memcg() we do not zero nid, when shrinker is not numa-aware. This is not a real problem, since currently all memcg-aware shrinkers are numa-aware too (we have two: super_block shrinker and workingset shrinker), but something may change in the future. Link: http://lkml.kernel.org/r/153320759911.18959.8842396230157677671.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
To avoid further unneed calls of do_shrink_slab() for shrinkers, which already do not have any charged objects in a memcg, their bits have to be cleared. This patch introduces a lockless mechanism to do that without races without parallel list lru add. After do_shrink_slab() returns SHRINK_EMPTY the first time, we clear the bit and call it once again. Then we restore the bit, if the new return value is different. Note, that single smp_mb__after_atomic() in shrink_slab_memcg() covers two situations: 1)list_lru_add() shrink_slab_memcg list_add_tail() for_each_set_bit() <--- read bit do_shrink_slab() <--- missed list update (no barrier) <MB> <MB> set_bit() do_shrink_slab() <--- seen list update This situation, when the first do_shrink_slab() sees set bit, but it doesn't see list update (i.e., race with the first element queueing), is rare. So we don't add <MB> before the first call of do_shrink_slab() instead of this to do not slow down generic case. Also, it's need the second call as seen in below in (2). 2)list_lru_add() shrink_slab_memcg() list_add_tail() ... set_bit() ... ... for_each_set_bit() do_shrink_slab() do_shrink_slab() clear_bit() ... ... ... list_lru_add() ... list_add_tail() clear_bit() <MB> <MB> set_bit() do_shrink_slab() The barriers guarantee that the second do_shrink_slab() in the right side task sees list update if really cleared the bit. This case is drawn in the code comment. [Results/performance of the patchset] After the whole patchset applied the below test shows signify increase of performance: $echo 1 > /sys/fs/cgroup/memory/memory.use_hierarchy $mkdir /sys/fs/cgroup/memory/ct $echo 4000M > /sys/fs/cgroup/memory/ct/memory.kmem.limit_in_bytes $for i in `seq 0 4000`; do mkdir /sys/fs/cgroup/memory/ct/$i; echo $$ > /sys/fs/cgroup/memory/ct/$i/cgroup.procs; mkdir -p s/$i; mount -t tmpfs $i s/$i; touch s/$i/file; done Then, 5 sequential calls of drop caches: $time echo 3 > /proc/sys/vm/drop_caches 1)Before: 0.00user 13.78system 0:13.78elapsed 99%CPU 0.00user 5.59system 0:05.60elapsed 99%CPU 0.00user 5.48system 0:05.48elapsed 99%CPU 0.00user 8.35system 0:08.35elapsed 99%CPU 0.00user 8.34system 0:08.35elapsed 99%CPU 2)After 0.00user 1.10system 0:01.10elapsed 99%CPU 0.00user 0.00system 0:00.01elapsed 64%CPU 0.00user 0.01system 0:00.01elapsed 82%CPU 0.00user 0.00system 0:00.01elapsed 64%CPU 0.00user 0.01system 0:00.01elapsed 82%CPU The results show the performance increases at least in 548 times. Shakeel Butt tested this patchset with fork-bomb on his configuration: > I created 255 memcgs, 255 ext4 mounts and made each memcg create a > file containing few KiBs on corresponding mount. Then in a separate > memcg of 200 MiB limit ran a fork-bomb. > > I ran the "perf record -ag -- sleep 60" and below are the results: > > Without the patch series: > Samples: 4M of event 'cycles', Event count (approx.): 3279403076005 > + 36.40% fb.sh [kernel.kallsyms] [k] shrink_slab > + 18.97% fb.sh [kernel.kallsyms] [k] list_lru_count_one > + 6.75% fb.sh [kernel.kallsyms] [k] super_cache_count > + 0.49% fb.sh [kernel.kallsyms] [k] down_read_trylock > + 0.44% fb.sh [kernel.kallsyms] [k] mem_cgroup_iter > + 0.27% fb.sh [kernel.kallsyms] [k] up_read > + 0.21% fb.sh [kernel.kallsyms] [k] osq_lock > + 0.13% fb.sh [kernel.kallsyms] [k] shmem_unused_huge_count > + 0.08% fb.sh [kernel.kallsyms] [k] shrink_node_memcg > + 0.08% fb.sh [kernel.kallsyms] [k] shrink_node > > With the patch series: > Samples: 4M of event 'cycles', Event count (approx.): 2756866824946 > + 47.49% fb.sh [kernel.kallsyms] [k] down_read_trylock > + 30.72% fb.sh [kernel.kallsyms] [k] up_read > + 9.51% fb.sh [kernel.kallsyms] [k] mem_cgroup_iter > + 1.69% fb.sh [kernel.kallsyms] [k] shrink_node_memcg > + 1.35% fb.sh [kernel.kallsyms] [k] mem_cgroup_protected > + 1.05% fb.sh [kernel.kallsyms] [k] queued_spin_lock_slowpath > + 0.85% fb.sh [kernel.kallsyms] [k] _raw_spin_lock > + 0.78% fb.sh [kernel.kallsyms] [k] lruvec_lru_size > + 0.57% fb.sh [kernel.kallsyms] [k] shrink_node > + 0.54% fb.sh [kernel.kallsyms] [k] queue_work_on > + 0.46% fb.sh [kernel.kallsyms] [k] shrink_slab_memcg [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112561772.4097.11011071937553113003.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063070859.1818.11870882950920963480.stgit@localhost.localdomainSigned-off-by:Vladimir Davydov <vdavydov.dev@gmail.com> Tested-by:
Shakeel Butt <shakeelb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <jbacik@fb.com> Cc: Li RongQing <lirongqing@baidu.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Roman Gushchin <guro@fb.com> Cc: Sahitya Tummala <stummala@codeaurora.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Signed-off-by:
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Kirill Tkhai authored
We need to distinguish the situations when shrinker has very small amount of objects (see vfs_pressure_ratio() called from super_cache_count()), and when it has no objects at all. Currently, in the both of these cases, shrinker::count_objects() returns 0. The patch introduces new SHRINK_EMPTY return value, which will be used for "no objects at all" case. It's is a refactoring mostly, as SHRINK_EMPTY is replaced by 0 by all callers of do_shrink_slab() in this patch, and all the magic will happen in further. Link: http://lkml.kernel.org/r/153063069574.1818.11037751256699341813.stgit@localhost.localdomainSigned-off-by:
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Vladimir Davydov authored
The patch makes shrink_slab() be called for root_mem_cgroup in the same way as it's called for the rest of cgroups. This simplifies the logic and improves the readability. [ktkhai@virtuozzo.com: wrote changelog] Link: http://lkml.kernel.org/r/153063068338.1818.11496084754797453962.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Using the preparations made in previous patches, in case of memcg shrink, we may avoid shrinkers, which are not set in memcg's shrinkers bitmap. To do that, we separate iterations over memcg-aware and !memcg-aware shrinkers, and memcg-aware shrinkers are chosen via for_each_set_bit() from the bitmap. In case of big nodes, having many isolated environments, this gives significant performance growth. See next patches for the details. Note that the patch does not respect to empty memcg shrinkers, since we never clear the bitmap bits after we set it once. Their shrinkers will be called again, with no shrinked objects as result. This functionality is provided by next patches. [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112558507.4097.12713813335683345488.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063066653.1818.976035462801487910.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Introduce set_shrinker_bit() function to set shrinker-related bit in memcg shrinker bitmap, and set the bit after the first item is added and in case of reparenting destroyed memcg's items. This will allow next patch to make shrinkers be called only, in case of they have charged objects at the moment, and to improve shrink_slab() performance. [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112557572.4097.17315791419810749985.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063065671.1818.15914674956134687268.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
This will be used in next patch. Link: http://lkml.kernel.org/r/153063064347.1818.1987011484100392706.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
This is just refactoring to allow next patches to have lru pointer in memcg_drain_list_lru_node(). Link: http://lkml.kernel.org/r/153063063164.1818.55009531386089350.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
This is just refactoring to allow the next patches to have dst_memcg pointer in memcg_drain_list_lru_node(). Link: http://lkml.kernel.org/r/153063062118.1818.2761273817739499749.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
This is just refactoring to allow the next patches to have memcg pointer in list_lru_from_kmem(). Link: http://lkml.kernel.org/r/153063060664.1818.9541345386733498582.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Add list_lru::shrinker_id field and populate it by registered shrinker id. This will be used to set correct bit in memcg shrinkers map by lru code in next patches, after there appeared the first related to memcg element in list_lru. Link: http://lkml.kernel.org/r/153063059758.1818.14866596416857717800.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Do two list_lru_init_memcg() calls after prealloc_super(). destroy_unused_super() in fail path is OK with this. Next patch needs such the order. Link: http://lkml.kernel.org/r/153063058712.1818.3382490999719078571.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Use prealloc_shrinker()/register_shrinker_prepared() instead of register_shrinker(). This will be used in next patch. [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112550112.4097.16606173020912323761.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063057666.1818.17625951186610808734.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Imagine a big node with many cpus, memory cgroups and containers. Let we have 200 containers, every container has 10 mounts, and 10 cgroups. All container tasks don't touch foreign containers mounts. If there is intensive pages write, and global reclaim happens, a writing task has to iterate over all memcgs to shrink slab, before it's able to go to shrink_page_list(). Iteration over all the memcg slabs is very expensive: the task has to visit 200 * 10 = 2000 shrinkers for every memcg, and since there are 2000 memcgs, the total calls are 2000 * 2000 = 4000000. So, the shrinker makes 4 million do_shrink_slab() calls just to try to isolate SWAP_CLUSTER_MAX pages in one of the actively writing memcg via shrink_page_list(). I've observed a node spending almost 100% in kernel, making useless iteration over already shrinked slab. This patch adds bitmap of memcg-aware shrinkers to memcg. The size of the bitmap depends on bitmap_nr_ids, and during memcg life it's maintained to be enough to fit bitmap_nr_ids shrinkers. Every bit in the map is related to corresponding shrinker id. Next patches will maintain set bit only for really charged memcg. This will allow shrink_slab() to increase its performance in significant way. See the last patch for the numbers. [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112549031.4097.3576147070498769979.stgit@localhost.localdomain [ktkhai@virtuozzo.com: add comment to mem_cgroup_css_online()] Link: http://lkml.kernel.org/r/521f9e5f-c436-b388-fe83-4dc870bfb489@virtuozzo.com Link: http://lkml.kernel.org/r/153063056619.1818.12550500883688681076.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Next patch requires these defines are above their current position, so here they are moved to declarations. Link: http://lkml.kernel.org/r/153063055665.1818.5200425793649695598.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Introduce shrinker::id number, which is used to enumerate memcg-aware shrinkers. The number start from 0, and the code tries to maintain it as small as possible. This will be used to represent a memcg-aware shrinkers in memcg shrinkers map. Since all memcg-aware shrinkers are based on list_lru, which is per-memcg in case of !CONFIG_MEMCG_KMEM only, the new functionality will be under this config option. [ktkhai@virtuozzo.com: v9] Link: http://lkml.kernel.org/r/153112546435.4097.10607140323811756557.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/153063054586.1818.6041047871606697364.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Introduce new config option, which is used to replace repeating CONFIG_MEMCG && !CONFIG_SLOB pattern. Next patches add a little more memcg+kmem related code, so let's keep the defines more clearly. Link: http://lkml.kernel.org/r/153063053670.1818.15013136946600481138.stgit@localhost.localdomainSigned-off-by:
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Kirill Tkhai authored
Patch series "Improve shrink_slab() scalability (old complexity was O(n^2), new is O(n))", v8. This patcheset solves the problem with slow shrink_slab() occuring on the machines having many shrinkers and memory cgroups (i.e., with many containers). The problem is complexity of shrink_slab() is O(n^2) and it grows too fast with the growth of containers numbers. Let us have 200 containers, and every container has 10 mounts and 10 cgroups. All container tasks are isolated, and they don't touch foreign containers mounts. In case of global reclaim, a task has to iterate all over the memcgs and to call all the memcg-aware shrinkers for all of them. This means, the task has to visit 200 * 10 = 2000 shrinkers for every memcg, and since there are 2000 memcgs, the total calls of do_shrink_slab() are 2000 * 2000 = 4000000. 4 million calls are not a number operations, which can takes 1 cpu cycle. E.g., super_cache_count() accesses at least two lists, and makes arifmetical calculations. Even, if there are no charged objects, we do these calculations, and replaces cpu caches by read memory. I observed nodes spending almost 100% time in kernel, in case of intensive writing and global reclaim. The writer consumes pages fast, but it's need to shrink_slab() before the reclaimer reached shrink pages function (and frees SWAP_CLUSTER_MAX pages). Even if there is no writing, the iterations just waste the time, and slows reclaim down. Let's see the small test below: $echo 1 > /sys/fs/cgroup/memory/memory.use_hierarchy $mkdir /sys/fs/cgroup/memory/ct $echo 4000M > /sys/fs/cgroup/memory/ct/memory.kmem.limit_in_bytes $for i in `seq 0 4000`; do mkdir /sys/fs/cgroup/memory/ct/$i; echo $$ > /sys/fs/cgroup/memory/ct/$i/cgroup.procs; mkdir -p s/$i; mount -t tmpfs $i s/$i; touch s/$i/file; done Then, let's see drop caches time (5 sequential calls): $time echo 3 > /proc/sys/vm/drop_caches 0.00user 13.78system 0:13.78elapsed 99%CPU 0.00user 5.59system 0:05.60elapsed 99%CPU 0.00user 5.48system 0:05.48elapsed 99%CPU 0.00user 8.35system 0:08.35elapsed 99%CPU 0.00user 8.34system 0:08.35elapsed 99%CPU The last four calls don't actually shrink anything. So, the iterations over slab shrinkers take 5.48 seconds. Not so good for scalability. The patchset solves the problem by making shrink_slab() of O(n) complexity. There are following functional actions: 1) Assign id to every registered memcg-aware shrinker. 2) Maintain per-memcgroup bitmap of memcg-aware shrinkers, and set a shrinker-related bit after the first element is added to lru list (also, when removed child memcg elements are reparanted). 3) Split memcg-aware shrinkers and !memcg-aware shrinkers, and call a shrinker if its bit is set in memcg's shrinker bitmap. (Also, there is a functionality to clear the bit, after last element is shrinked). This gives significant performance increase. The result after patchset is applied: $time echo 3 > /proc/sys/vm/drop_caches 0.00user 1.10system 0:01.10elapsed 99%CPU 0.00user 0.00system 0:00.01elapsed 64%CPU 0.00user 0.01system 0:00.01elapsed 82%CPU 0.00user 0.00system 0:00.01elapsed 64%CPU 0.00user 0.01system 0:00.01elapsed 82%CPU The results show the performance increases at least in 548 times. So, the patchset makes shrink_slab() of less complexity and improves the performance in such types of load I pointed. This will give a profit in case of !global reclaim case, since there also will be less do_shrink_slab() calls. This patch (of 17): These two pairs of blocks of code are under the same #ifdef #else #endif. Link: http://lkml.kernel.org/r/153063052519.1818.9393587113056959488.stgit@localhost.localdomainSigned-off-by: -
Mike Rapoport authored
Most functions in memblock already use phys_addr_t to represent a physical address with __memblock_free_late() being an exception. This patch replaces u64 with phys_addr_t in __memblock_free_late() and switches several format strings from %llx to %pa to avoid casting from phys_addr_t to u64. Link: http://lkml.kernel.org/r/1530637506-1256-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by:
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Oscar Salvador authored
sparse_init_one_section() is being called from two sites: sparse_init() and sparse_add_one_section(). The former calls it from a for_each_present_section_nr() loop, and the latter marks the section as present before calling it. This means that when sparse_init_one_section() gets called, we already know that the section is present. So there is no point to double check that in the function. This removes the check and makes the function void. [ross.zwisler@linux.intel.com: fix error path in sparse_add_one_section] Link: http://lkml.kernel.org/r/20180706190658.6873-1-ross.zwisler@linux.intel.com [ross.zwisler@linux.intel.com: simplification suggested by Oscar] Link: http://lkml.kernel.org/r/20180706223358.742-1-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/20180702154325.12196-1-osalvador@techadventures.netSigned-off-by:
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Michal Hocko authored
Commit 3812c8c8 ("mm: memcg: do not trap chargers with full callstack on OOM") has changed the ENOMEM semantic of memcg charges. Rather than invoking the oom killer from the charging context it delays the oom killer to the page fault path (pagefault_out_of_memory). This in turn means that many users (e.g. slab or g-u-p) will get ENOMEM when the corresponding memcg hits the hard limit and the memcg is is OOM. This is behavior is inconsistent with !memcg case where the oom killer is invoked from the allocation context and the allocator keeps retrying until it succeeds. The difference in the behavior is user visible. mmap(MAP_POPULATE) might result in not fully populated ranges while the mmap return code doesn't tell that to the userspace. Random syscalls might fail with ENOMEM etc. The primary motivation of the different memcg oom semantic was the deadlock avoidance. Things have changed since then, though. We have an async oom teardown by the oom reaper now and so we do not have to rely on the victim to tear down its memory anymore. Therefore we can return to the original semantic as long as the memcg oom killer is not handed over to the users space. There is still one thing to be careful about here though. If the oom killer is not able to make any forward progress - e.g. because there is no eligible task to kill - then we have to bail out of the charge path to prevent from same class of deadlocks. We have basically two options here. Either we fail the charge with ENOMEM or force the charge and allow overcharge. The first option has been considered more harmful than useful because rare inconsistencies in the ENOMEM behavior is hard to test for and error prone. Basically the same reason why the page allocator doesn't fail allocations under such conditions. The later might allow runaways but those should be really unlikely unless somebody misconfigures the system. E.g. allowing to migrate tasks away from the memcg to a different unlimited memcg with move_charge_at_immigrate disabled. Link: http://lkml.kernel.org/r/20180628151101.25307-1-mhocko@kernel.orgSigned-off-by:
Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by:
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Mike Rapoport authored
The deferred memory initialization relies on section definitions, e.g PAGES_PER_SECTION, that are only available when CONFIG_SPARSEMEM=y on most architectures. Initially DEFERRED_STRUCT_PAGE_INIT depended on explicit ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT configuration option, but since the commit 2e3ca40f ("mm: relax deferred struct page requirements") this requirement was relaxed and now it is possible to enable DEFERRED_STRUCT_PAGE_INIT on architectures that support DISCONTINGMEM and NO_BOOTMEM which causes build failures. For instance, setting SMP=y and DEFERRED_STRUCT_PAGE_INIT=y on arc causes the following build failure: CC mm/page_alloc.o mm/page_alloc.c: In function 'update_defer_init': mm/page_alloc.c:321:14: error: 'PAGES_PER_SECTION' undeclared (first use in this function); did you mean 'USEC_PER_SEC'? (pfn & (PAGES_PER_SECTION - 1)) == 0) { ^~~~~~~~~~~~~~~~~ USEC_PER_SEC mm/page_alloc.c:321:14: note: each undeclared identifier is reported only once for each function it appears in In file included from include/linux/cache.h:5:0, from include/linux/printk.h:9, from include/linux/kernel.h:14, from include/asm-generic/bug.h:18, from arch/arc/include/asm/bug.h:32, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/mm.h:9, from mm/page_alloc.c:18: mm/page_alloc.c: In function 'deferred_grow_zone': mm/page_alloc.c:1624:52: error: 'PAGES_PER_SECTION' undeclared (first use in this function); did you mean 'USEC_PER_SEC'? unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION); ^ include/uapi/linux/kernel.h:11:47: note: in definition of macro '__ALIGN_KERNEL_MASK' #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask)) ^~~~ include/linux/kernel.h:58:22: note: in expansion of macro '__ALIGN_KERNEL' #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) ^~~~~~~~~~~~~~ mm/page_alloc.c:1624:34: note: in expansion of macro 'ALIGN' unsigned long nr_pages_needed = ALIGN(1 << order, PAGES_PER_SECTION); ^~~~~ In file included from include/asm-generic/bug.h:18:0, from arch/arc/include/asm/bug.h:32, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/mm.h:9, from mm/page_alloc.c:18: mm/page_alloc.c: In function 'free_area_init_node': mm/page_alloc.c:6379:50: error: 'PAGES_PER_SECTION' undeclared (first use in this function); did you mean 'USEC_PER_SEC'? pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION, ^ include/linux/kernel.h:812:22: note: in definition of macro '__typecheck' (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) ^ include/linux/kernel.h:836:24: note: in expansion of macro '__safe_cmp' __builtin_choose_expr(__safe_cmp(x, y), \ ^~~~~~~~~~ include/linux/kernel.h:904:27: note: in expansion of macro '__careful_cmp' #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <) ^~~~~~~~~~~~~ mm/page_alloc.c:6379:29: note: in expansion of macro 'min_t' pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION, ^~~~~ include/linux/kernel.h:836:2: error: first argument to '__builtin_choose_expr' not a constant __builtin_choose_expr(__safe_cmp(x, y), \ ^ include/linux/kernel.h:904:27: note: in expansion of macro '__careful_cmp' #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <) ^~~~~~~~~~~~~ mm/page_alloc.c:6379:29: note: in expansion of macro 'min_t' pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION, ^~~~~ scripts/Makefile.build:317: recipe for target 'mm/page_alloc.o' failed Let's make the DEFERRED_STRUCT_PAGE_INIT explicitly depend on SPARSEMEM as the systems that support DISCONTIGMEM do not seem to have that huge amounts of memory that would make DEFERRED_STRUCT_PAGE_INIT relevant. Link: http://lkml.kernel.org/r/1530279308-24988-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Randy Dunlap <rdunlap@infradead.org> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Signed-off-by:
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Andrey Ryabinin authored
KASAN learns about hotadded memory via the memory hotplug notifier. devm_memremap_pages() intentionally skips calling memory hotplug notifiers. So KASAN doesn't know anything about new memory added by devm_memremap_pages(). This causes a crash when KASAN tries to access non-existent shadow memory: BUG: unable to handle kernel paging request at ffffed0078000000 RIP: 0010:check_memory_region+0x82/0x1e0 Call Trace: memcpy+0x1f/0x50 pmem_do_bvec+0x163/0x720 pmem_make_request+0x305/0xac0 generic_make_request+0x54f/0xcf0 submit_bio+0x9c/0x370 submit_bh_wbc+0x4c7/0x700 block_read_full_page+0x5ef/0x870 do_read_cache_page+0x2b8/0xb30 read_dev_sector+0xbd/0x3f0 read_lba.isra.0+0x277/0x670 efi_partition+0x41a/0x18f0 check_partition+0x30d/0x5e9 rescan_partitions+0x18c/0x840 __blkdev_get+0x859/0x1060 blkdev_get+0x23f/0x810 __device_add_disk+0x9c8/0xde0 pmem_attach_disk+0x9a8/0xf50 nvdimm_bus_probe+0xf3/0x3c0 driver_probe_device+0x493/0xbd0 bus_for_each_drv+0x118/0x1b0 __device_attach+0x1cd/0x2b0 bus_probe_device+0x1ac/0x260 device_add+0x90d/0x1380 nd_async_device_register+0xe/0x50 async_run_entry_fn+0xc3/0x5d0 process_one_work+0xa0a/0x1810 worker_thread+0x87/0xe80 kthread+0x2d7/0x390 ret_from_fork+0x3a/0x50 Add kasan_add_zero_shadow()/kasan_remove_zero_shadow() - post mm_init() interface to map/unmap kasan_zero_page at requested virtual addresses. And use it to add/remove the shadow memory for hotplugged/unplugged device memory. Link: http://lkml.kernel.org/r/20180629164932.740-1-aryabinin@virtuozzo.com Fixes: 41e94a85 ("add devm_memremap_pages") Signed-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by:
Dave Chinner <david@fromorbit.com> Reviewed-by:
Dan Williams <dan.j.williams@intel.com> Tested-by:
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Song Liu authored
khugepaged_enter_vma_merge() passes a stale vma->vm_flags to hugepage_vma_check(). The argument vm_flags contains the latest value. Therefore, it is necessary to pass this vm_flags into hugepage_vma_check(). With this bug, madvise(MADV_HUGEPAGE) for mmap files in shmem fails to put memory in huge pages. Here is an example of failed madvise(): /* mount /dev/shm with huge=advise: * mount -o remount,huge=advise /dev/shm */ /* create file /dev/shm/huge */ #define HUGE_FILE "/dev/shm/huge" fd = open(HUGE_FILE, O_RDONLY); ptr = mmap(NULL, FILE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0); ret = madvise(ptr, FILE_SIZE, MADV_HUGEPAGE); madvise() will return 0, but this memory region is never put in huge page (check from /proc/meminfo: ShmemHugePages). Link: http://lkml.kernel.org/r/20180629181752.792831-1-songliubraving@fb.com Fixes: 02b75dc8160d ("mm: thp: register mm for khugepaged when merging vma for shmem") Signed-off-by:Song Liu <songliubraving@fb.com> Reviewed-by:
Yang Shi <yang.shi@linux.alibaba.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Andrey Ryabinin authored
Signed integer overflow is undefined according to the C standard. The overflow in ksys_fadvise64_64() is deliberate, but since it is signed overflow, UBSAN complains: UBSAN: Undefined behaviour in mm/fadvise.c:76:10 signed integer overflow: 4 + 9223372036854775805 cannot be represented in type 'long long int' Use unsigned types to do math. Unsigned overflow is defined so UBSAN will not complain about it. This patch doesn't change generated code. [akpm@linux-foundation.org: add comment explaining the casts] Link: http://lkml.kernel.org/r/20180629184453.7614-1-aryabinin@virtuozzo.comSigned-off-by:
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