- 16 Nov, 2014 18 commits
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Eric Dumazet authored
Use of well known RSS key increases attack surface. Switch to a random one, using generic helper so that all ports share a common key. Signed-off-by:
Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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Eric Dumazet authored
Use of well known RSS key increases attack surface. Switch to a random one, using generic helper so that all ports share a common key. Signed-off-by:
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Eric Dumazet authored
Use of well known RSS key increases attack surface. Switch to a random one, using generic helper so that all ports share a common key. Signed-off-by:
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Eric Dumazet authored
Use of well known RSS key increases attack surface. Switch to a random one, using generic helper so that all ports share a common key. Signed-off-by:
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Eric Dumazet authored
Use netdev_rss_key_fill() helper, as it provides better support for some bonding setups. Rename rss_hkey local variable to rss_key to have consistent name among drivers. Signed-off-by:
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Eric Dumazet authored
Use netdev_rss_key_fill() helper, as it provides better support for some bonding setups. Signed-off-by:
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Eric Dumazet authored
Use of well known RSS key increases attack surface. Switch to a random one, using generic helper so that all ports share a common key. Signed-off-by:
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Eric Dumazet authored
Use netdev_rss_key_fill() helper, as it provides better support for some bonding setups. Signed-off-by:
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Eric Dumazet authored
Use netdev_rss_key_fill() helper, as it provides better support for some bonding setups. Signed-off-by:
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Eric Dumazet authored
RSS (Receive Side Scaling) typically uses Toeplitz hash and a 40 or 52 bytes RSS key. Some drivers use a constant (and well known key), some drivers use a random key per port, making bonding setups hard to tune. Well known keys increase attack surface, considering that number of queues is usually a power of two. This patch provides infrastructure to help drivers doing the right thing. netdev_rss_key_fill() should be used by drivers to initialize their RSS key, even if they provide ethtool -X support to let user redefine the key later. A new /proc/sys/net/core/netdev_rss_key file can be used to get the host RSS key even for drivers not providing ethtool -x support, in case some applications want to precisely setup flows to match some RX queues. Tested: myhost:~# cat /proc/sys/net/core/netdev_rss_key 11:63:99:bb:79:fb:a5:a7:07:45:b2:20:bf:02:42:2d:08:1a:dd:19:2b:6b:23:ac:56:28:9d:70:c3:ac:e8:16:4b:b7:c1:10:53:a4:78:41:36:40:74:b6:15:ca:27:44:aa:b3:4d:72 myhost:~# ethtool -x eth0 RX flow hash indirection table for eth0 with 8 RX ring(s): 0: 0 1 2 3 4 5 6 7 RSS hash key: 11:63:99:bb:79:fb:a5:a7:07:45:b2:20:bf:02:42:2d:08:1a:dd:19:2b:6b:23:ac:56:28:9d:70:c3:ac:e8:16:4b:b7:c1:10:53:a4:78:41 Signed-off-by: -
David S. Miller authored
Andrew Lunn says: ==================== Add temperature reading and registers dump to mv88e6171 These patches centralize the temperature sensor reading code, and then make use of it with the mv88e6171 which has a compatible sensor. Additionally, support is added for reading the mv88e6171 via ethtool. ==================== Signed-off-by: -
Andrew Lunn authored
The infrastructure can now report switch registers to ethtool. Add support for it to the mv88e6171 driver. Signed-off-by:
Andrew Lunn <andrew@lunn.ch> Signed-off-by:
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Andrew Lunn authored
This chip also has a temperature sensor which can be read using the common code. In order to use it, add the needed mutex protection for accessing registers via the shared code. Signed-off-by:
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Andrew Lunn authored
The method to read the temperature used in the mve6123_61_65 driver can also be used for other chips. Move the code into the shared code base of mv88e6xxx.c. Signed-off-by:
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Fabian Frederick authored
kcalloc manages count*sizeof overflow. Signed-off-by:
Fabian Frederick <fabf@skynet.be> Signed-off-by:
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Fabian Frederick authored
kmalloc_array manages count*sizeof overflow. Signed-off-by:
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Fabian Frederick authored
Signed-off-by:
Pravin B Shelar <pshelar@nicira.com> Signed-off-by:
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Holger Brunck authored
There is no reason to limit the amount of possible links to a neighboring node to 2. If we have more then two bearers we can also establish more links. Signed-off-by:
Holger Brunck <holger.brunck@keymile.com> Reviewed-By:
Jon Maloy <jon.maloy@ericsson.com> cc: Ying Xue <ying.xue@windriver.com> cc: Erik Hugne <erik.hugne@ericsson.com> cc: netdev@vger.kernel.org Signed-off-by:
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- 14 Nov, 2014 22 commits
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Jay Vosburgh authored
This reverts commit e5a2c899. Commit e5a2c899 introduced an alternative_call, arch_fast_hash2, that selects between __jhash2 and __intel_crc4_2_hash based on the X86_FEATURE_XMM4_2. Unfortunately, the alternative_call system does not appear to be suitable for use with C functions, as register usage is not handled properly for the called functions. The __jhash2 function in particular clobbers registers that are not preserved when called via alternative_call, resulting in a panic for direct callers of arch_fast_hash2 on older CPUs lacking sse4_2. It is possible that __intel_crc4_2_hash works merely by chance because it uses fewer registers. This commit was suggested as the source of the problem by Jesse Gross <jesse@nicira.com>. Signed-off-by:
Jay Vosburgh <jay.vosburgh@canonical.com> Signed-off-by:
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Pravin B Shelar authored
Add dependency on INET to fix following build error. I have also fixed MPLS dependency. ERROR: "ip_route_output_flow" [net/openvswitch/openvswitch.ko] undefined! make[1]: *** [__modpost] Error 1 Reported-by:
Jim Davis <jim.epost@gmail.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller authored
Conflicts: drivers/net/ethernet/chelsio/cxgb4vf/sge.c drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c sge.c was overlapping two changes, one to use the new __dev_alloc_page() in net-next, and one to use s->fl_pg_order in net. ixgbe_phy.c was a set of overlapping whitespace changes. Signed-off-by: -
git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds authored
Pull virtio bugfix from Michael S Tsirkin: "This fixes a crash in virtio console multi-channel mode that got introduced in -rc1" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio_console: move early VQ enablement
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds authored
Pull networking fixes from David Miller: 1) sunhme driver lacks DMA mapping error checks, based upon a report by Meelis Roos. 2) Fix memory leak in mvpp2 driver, from Sudip Mukherjee. 3) DMA memory allocation sizes are wrong in systemport ethernet driver, fix from Florian Fainelli. 4) Fix use after free in mac80211 defragmentation code, from Johannes Berg. 5) Some networking uapi headers missing from Kbuild file, from Stephen Hemminger. 6) TUN driver gets csum_start offset wrong when VLAN accel is enabled, and macvtap has a similar bug, from Herbert Xu. 7) Adjust several tunneling drivers to set dev->iflink after registry, because registry sets that to -1 overwriting whatever we did. From Steffen Klassert. 8) Geneve forgets to set inner tunneling type, causing GSO segmentation to fail on some NICs. From Jesse Gross. 9) Fix several locking bugs in stmmac driver, from Fabrice Gasnier and Giuseppe CAVALLARO. 10) Fix spurious timeouts with NewReno on low traffic connections, from Marcelo Leitner. 11) Fix descriptor updates in enic driver, from Govindarajulu Varadarajan. 12) PPP calls bpf_prog_create() with locks held, which isn't kosher. Fix from Takashi Iwai. 13) Fix NULL deref in SCTP with malformed INIT packets, from Daniel Borkmann. 14) psock_fanout selftest accesses past the end of the mmap ring, fix from Shuah Khan. 15) Fix PTP timestamping for VLAN packets, from Richard Cochran. 16) netlink_unbind() calls in netlink pass wrong initial argument, from Hiroaki SHIMODA. 17) vxlan socket reuse accidently reuses a socket when the address family is different, so we have to explicitly check this, from Marcelo Lietner. 18) Fix missing include in nft_reject_bridge.c breaking the build on ppc and other architectures, from Guenter Roeck. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (75 commits) vxlan: Do not reuse sockets for a different address family smsc911x: power-up phydev before doing a software reset. lib: rhashtable - Remove weird non-ASCII characters from comments net/smsc911x: Fix delays in the PHY enable/disable routines net/smsc911x: Fix rare soft reset timeout issue due to PHY power-down mode netlink: Properly unbind in error conditions. net: ptp: fix time stamp matching logic for VLAN packets. cxgb4 : dcb open-lldp interop fixes selftests/net: psock_fanout seg faults in sock_fanout_read_ring() net: bcmgenet: apply MII configuration in bcmgenet_open() net: bcmgenet: connect and disconnect from the PHY state machine net: qualcomm: Fix dependency ixgbe: phy: fix uninitialized status in ixgbe_setup_phy_link_tnx net: phy: Correctly handle MII ioctl which changes autonegotiation. ipv6: fix IPV6_PKTINFO with v4 mapped net: sctp: fix memory leak in auth key management net: sctp: fix NULL pointer dereference in af->from_addr_param on malformed packet net: ppp: Don't call bpf_prog_create() in ppp_lock net/mlx4_en: Advertize encapsulation offloads features only when VXLAN tunnel is set cxgb4 : Fix bug in DCB app deletion ... -
Linus Torvalds authored
Merge misc fixes from Andrew Morton: "15 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: MAINTAINERS: add IIO include files kernel/panic.c: update comments for print_tainted mem-hotplug: reset node present pages when hot-adding a new pgdat mem-hotplug: reset node managed pages when hot-adding a new pgdat mm/debug-pagealloc: correct freepage accounting and order resetting fanotify: fix notification of groups with inode & mount marks mm, compaction: prevent infinite loop in compact_zone mm: alloc_contig_range: demote pages busy message from warn to info mm/slab: fix unalignment problem on Malta with EVA due to slab merge mm/page_alloc: restrict max order of merging on isolated pageblock mm/page_alloc: move freepage counting logic to __free_one_page() mm/page_alloc: add freepage on isolate pageblock to correct buddy list mm/page_alloc: fix incorrect isolation behavior by rechecking migratetype mm/compaction: skip the range until proper target pageblock is met zram: avoid kunmap_atomic() of a NULL pointer
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-clientLinus Torvalds authored
Pull Ceph fixes from Sage Weil: "There is an overflow bug fix for cephfs from Zheng, a fix for handling large authentication ticket buffers in libceph from Ilya, and a few fixes for the request handling code from Ilya that affect RBD volumes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: libceph: change from BUG to WARN for __remove_osd() asserts libceph: clear r_req_lru_item in __unregister_linger_request() libceph: unlink from o_linger_requests when clearing r_osd libceph: do not crash on large auth tickets ceph: fix flush tid comparision
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git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hidLinus Torvalds authored
Pull HID fixes from Jiri Kosina: - fix for an oops in HID core upon repeated subdriver insertion/removal under certain circumstances, by Benjamin Tissoires - quirk for another Elan Touchscreen device, by Adel Gadllah * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: HID: core: cleanup .claimed field on disconnect HID: usbhid: enable always-poll quirk for Elan Touchscreen 0103
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Daniel Baluta authored
Files under include/linux/iio were not reported as part of the IIO subsystem. Signed-off-by:
Daniel Baluta <daniel.baluta@intel.com> Reported-by:
Cristina Ciocan <cristina.ciocan@intel.com> Reviewed-by:
Jingoo Han <jg1.han@samsung.com> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Peter Meerwald <pmeerw@pmeerw.net> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Xie XiuQi authored
Commit 69361eef ("panic: add TAINT_SOFTLOCKUP") added the 'L' flag, but failed to update the comments for print_tainted(). So, update the comments. Signed-off-by:
Xie XiuQi <xiexiuqi@huawei.com> Signed-off-by:
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Tang Chen authored
When memory is hot-added, all the memory is in offline state. So clear all zones' present_pages because they will be updated in online_pages() and offline_pages(). Otherwise, /proc/zoneinfo will corrupt: When the memory of node2 is offline: # cat /proc/zoneinfo ...... Node 2, zone Movable ...... spanned 8388608 present 8388608 managed 0 When we online memory on node2: # cat /proc/zoneinfo ...... Node 2, zone Movable ...... spanned 8388608 present 16777216 managed 8388608 Signed-off-by:Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by:
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: <stable@vger.kernel.org> [3.16+] Signed-off-by:
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Tang Chen authored
In free_area_init_core(), zone->managed_pages is set to an approximate value for lowmem, and will be adjusted when the bootmem allocator frees pages into the buddy system. But free_area_init_core() is also called by hotadd_new_pgdat() when hot-adding memory. As a result, zone->managed_pages of the newly added node's pgdat is set to an approximate value in the very beginning. Even if the memory on that node has node been onlined, /sys/device/system/node/nodeXXX/meminfo has wrong value: hot-add node2 (memory not onlined) cat /sys/device/system/node/node2/meminfo Node 2 MemTotal: 33554432 kB Node 2 MemFree: 0 kB Node 2 MemUsed: 33554432 kB Node 2 Active: 0 kB This patch fixes this problem by reset node managed pages to 0 after hot-adding a new node. 1. Move reset_managed_pages_done from reset_node_managed_pages() to reset_all_zones_managed_pages() 2. Make reset_node_managed_pages() non-static 3. Call reset_node_managed_pages() in hotadd_new_pgdat() after pgdat is initialized Signed-off-by:
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Joonsoo Kim authored
One thing I did in this patch is fixing freepage accounting. If we clear guard page and link it onto isolate buddy list, we should not increase freepage count. This patch adds conditional branch to skip counting in this case. Without this patch, this overcounting happens frequently if guard order is set and CMA is used. Another thing fixed in this patch is the target to reset order. In __free_one_page(), we check the buddy page whether it is a guard page or not. And, if so, we should clear guard attribute on the buddy page and reset order of it to 0. But, current code resets original page's order rather than buddy one's. Maybe, this doesn't have any problem, because whole merged page's order will be re-assigned soon. But, it is better to correct code. Signed-off-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Gioh Kim <gioh.kim@lge.com> Signed-off-by:
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Jan Kara authored
fsnotify() needs to merge inode and mount marks lists when notifying groups about events so that ignore masks from inode marks are reflected in mount mark notifications and groups are notified in proper order (according to priorities). Currently the sorting of the lists done by fsnotify_add_inode_mark() / fsnotify_add_vfsmount_mark() and fsnotify() differed which resulted ignore masks not being used in some cases. Fix the problem by always using the same comparison function when sorting / merging the mark lists. Thanks to Heinrich Schuchardt for improvements of my patch. Link: https://bugzilla.kernel.org/show_bug.cgi?id=87721Signed-off-by:
Jan Kara <jack@suse.cz> Reported-by:
Heinrich Schuchardt <xypron.glpk@gmx.de> Tested-by:
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Vlastimil Babka authored
Several people have reported occasionally seeing processes stuck in compact_zone(), even triggering soft lockups, in 3.18-rc2+. Testing a revert of commit e14c720e ("mm, compaction: remember position within pageblock in free pages scanner") fixed the issue, although the stuck processes do not appear to involve the free scanner. Finally, by code inspection, the bug was found in isolate_migratepages() which uses a slightly different condition to detect if the migration and free scanners have met, than compact_finished(). That has not been a problem until commit e14c720e allowed the free scanner position between individual invocations to be in the middle of a pageblock. In a relatively rare case, the migration scanner position can end up at the beginning of a pageblock, with the free scanner position in the middle of the same pageblock. If it's the migration scanner's turn, isolate_migratepages() exits immediately (without updating the position), while compact_finished() decides to continue compaction, resulting in a potentially infinite loop. The system can recover only if another process creates enough high-order pages to make the watermark checks in compact_finished() pass. This patch fixes the immediate problem by bumping the migration scanner's position to meet the free scanner in isolate_migratepages(), when both are within the same pageblock. This causes compact_finished() to terminate properly. A more robust check in compact_finished() is planned as a cleanup for better future maintainability. Fixes: e14c720e ("mm, compaction: remember position within pageblock in free pages scanner) Signed-off-by:
P. Christeas <xrg@linux.gr> Tested-by:
Norbert Preining <preining@logic.at> Tested-by:
Pavel Machek <pavel@ucw.cz> Link: https://lkml.org/lkml/2014/11/7/164 Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by:
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Michal Nazarewicz authored
Having test_pages_isolated failure message as a warning confuses users into thinking that it is more serious than it really is. In reality, if called via CMA, allocation will be retried so a single test_pages_isolated failure does not prevent allocation from succeeding. Demote the warning message to an info message and reformat it such that the text "failed" does not appear and instead a less worrying "PFNS busy" is used. This message is trivially reproducible on a 10GB x86 machine on 3.16.y kernels configured with CONFIG_DMA_CMA. Signed-off-by:
Michal Nazarewicz <mina86@mina86.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by:
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Joonsoo Kim authored
Unlike SLUB, sometimes, object isn't started at the beginning of the slab in SLAB. This causes the unalignment problem after slab merging is supported by commit 12220dea ("mm/slab: support slab merge"). Following is the report from Markos that fail to boot on Malta with EVA. Calibrating delay loop... 19.86 BogoMIPS (lpj=99328) pid_max: default: 32768 minimum: 301 Mount-cache hash table entries: 4096 (order: 0, 16384 bytes) Mountpoint-cache hash table entries: 4096 (order: 0, 16384 bytes) Kernel bug detected[#1]: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-05639-g12220dea #1631 task: 1f04f5d8 ti: 1f050000 task.ti: 1f050000 epc : 80141190 alloc_unbound_pwq+0x234/0x304 Not tainted ra : 80141184 alloc_unbound_pwq+0x228/0x304 Process swapper/0 (pid: 1, threadinfo=1f050000, task=1f04f5d8, tls=00000000) Call Trace: alloc_unbound_pwq+0x234/0x304 apply_workqueue_attrs+0x11c/0x294 __alloc_workqueue_key+0x23c/0x470 init_workqueues+0x320/0x400 do_one_initcall+0xe8/0x23c kernel_init_freeable+0x9c/0x224 kernel_init+0x10/0x100 ret_from_kernel_thread+0x14/0x1c [ end trace cb88537fdc8fa200 ] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b alloc_unbound_pwq() allocates slab object from pool_workqueue. This kmem_cache requires 256 bytes alignment, but, current merging code doesn't honor that, and merge it with kmalloc-256. kmalloc-256 requires only cacheline size alignment so that above failure occurs. However, in x86, kmalloc-256 is luckily aligned in 256 bytes, so the problem didn't happen on it. To fix this problem, this patch introduces alignment mismatch check in find_mergeable(). This will fix the problem. Signed-off-by:
Markos Chandras <Markos.Chandras@imgtec.com> Tested-by:
Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
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Joonsoo Kim authored
Current pageblock isolation logic could isolate each pageblock individually. This causes freepage accounting problem if freepage with pageblock order on isolate pageblock is merged with other freepage on normal pageblock. We can prevent merging by restricting max order of merging to pageblock order if freepage is on isolate pageblock. A side-effect of this change is that there could be non-merged buddy freepage even if finishing pageblock isolation, because undoing pageblock isolation is just to move freepage from isolate buddy list to normal buddy list rather than to consider merging. So, the patch also makes undoing pageblock isolation consider freepage merge. When un-isolation, freepage with more than pageblock order and it's buddy are checked. If they are on normal pageblock, instead of just moving, we isolate the freepage and free it in order to get merged. Signed-off-by:
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Joonsoo Kim authored
All the caller of __free_one_page() has similar freepage counting logic, so we can move it to __free_one_page(). This reduce line of code and help future maintenance. This is also preparation step for "mm/page_alloc: restrict max order of merging on isolated pageblock" which fix the freepage counting problem on freepage with more than pageblock order. Signed-off-by:
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Joonsoo Kim authored
In free_pcppages_bulk(), we use cached migratetype of freepage to determine type of buddy list where freepage will be added. This information is stored when freepage is added to pcp list, so if isolation of pageblock of this freepage begins after storing, this cached information could be stale. In other words, it has original migratetype rather than MIGRATE_ISOLATE. There are two problems caused by this stale information. One is that we can't keep these freepages from being allocated. Although this pageblock is isolated, freepage will be added to normal buddy list so that it could be allocated without any restriction. And the other problem is incorrect freepage accounting. Freepages on isolate pageblock should not be counted for number of freepage. Following is the code snippet in free_pcppages_bulk(). /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ __free_one_page(page, page_to_pfn(page), zone, 0, mt); trace_mm_page_pcpu_drain(page, 0, mt); if (likely(!is_migrate_isolate_page(page))) { __mod_zone_page_state(zone, NR_FREE_PAGES, 1); if (is_migrate_cma(mt)) __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1); } As you can see above snippet, current code already handle second problem, incorrect freepage accounting, by re-fetching pageblock migratetype through is_migrate_isolate_page(page). But, because this re-fetched information isn't used for __free_one_page(), first problem would not be solved. This patch try to solve this situation to re-fetch pageblock migratetype before __free_one_page() and to use it for __free_one_page(). In addition to move up position of this re-fetch, this patch use optimization technique, re-fetching migratetype only if there is isolate pageblock. Pageblock isolation is rare event, so we can avoid re-fetching in common case with this optimization. This patch also correct migratetype of the tracepoint output. Signed-off-by:Minchan Kim <minchan@kernel.org> Acked-by:
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Joonsoo Kim authored
Before describing bugs itself, I first explain definition of freepage. 1. pages on buddy list are counted as freepage. 2. pages on isolate migratetype buddy list are *not* counted as freepage. 3. pages on cma buddy list are counted as CMA freepage, too. Now, I describe problems and related patch. Patch 1: There is race conditions on getting pageblock migratetype that it results in misplacement of freepages on buddy list, incorrect freepage count and un-availability of freepage. Patch 2: Freepages on pcp list could have stale cached information to determine migratetype of buddy list to go. This causes misplacement of freepages on buddy list and incorrect freepage count. Patch 4: Merging between freepages on different migratetype of pageblocks will cause freepages accouting problem. This patch fixes it. Without patchset [3], above problem doesn't happens on my CMA allocation test, because CMA reserved pages aren't used at all. So there is no chance for above race. With patchset [3], I did simple CMA allocation test and get below result: - Virtual machine, 4 cpus, 1024 MB memory, 256 MB CMA reservation - run kernel build (make -j16) on background - 30 times CMA allocation(8MB * 30 = 240MB) attempts in 5 sec interval - Result: more than 5000 freepage count are missed With patchset [3] and this patchset, I found that no freepage count are missed so that I conclude that problems are solved. On my simple memory offlining test, these problems also occur on that environment, too. This patch (of 4): There are two paths to reach core free function of buddy allocator, __free_one_page(), one is free_one_page()->__free_one_page() and the other is free_hot_cold_page()->free_pcppages_bulk()->__free_one_page(). Each paths has race condition causing serious problems. At first, this patch is focused on first type of freepath. And then, following patch will solve the problem in second type of freepath. In the first type of freepath, we got migratetype of freeing page without holding the zone lock, so it could be racy. There are two cases of this race. 1. pages are added to isolate buddy list after restoring orignal migratetype CPU1 CPU2 get migratetype => return MIGRATE_ISOLATE call free_one_page() with MIGRATE_ISOLATE grab the zone lock unisolate pageblock release the zone lock grab the zone lock call __free_one_page() with MIGRATE_ISOLATE freepage go into isolate buddy list, although pageblock is already unisolated This may cause two problems. One is that we can't use this page anymore until next isolation attempt of this pageblock, because freepage is on isolate buddy list. The other is that freepage accouting could be wrong due to merging between different buddy list. Freepages on isolate buddy list aren't counted as freepage, but ones on normal buddy list are counted as freepage. If merge happens, buddy freepage on normal buddy list is inevitably moved to isolate buddy list without any consideration of freepage accouting so it could be incorrect. 2. pages are added to normal buddy list while pageblock is isolated. It is similar with above case. This also may cause two problems. One is that we can't keep these freepages from being allocated. Although this pageblock is isolated, freepage would be added to normal buddy list so that it could be allocated without any restriction. And the other problem is same as case 1, that it, incorrect freepage accouting. This race condition would be prevented by checking migratetype again with holding the zone lock. Because it is somewhat heavy operation and it isn't needed in common case, we want to avoid rechecking as much as possible. So this patch introduce new variable, nr_isolate_pageblock in struct zone to check if there is isolated pageblock. With this, we can avoid to re-check migratetype in common case and do it only if there is isolated pageblock or migratetype is MIGRATE_ISOLATE. This solve above mentioned problems. Changes from v3: Add one more check in free_one_page() that checks whether migratetype is MIGRATE_ISOLATE or not. Without this, abovementioned case 1 could happens. Signed-off-by: -
Joonsoo Kim authored
Commit 7d49d886 ("mm, compaction: reduce zone checking frequency in the migration scanner") has a side-effect that changes the iteration range calculation. Before the change, block_end_pfn is calculated using start_pfn, but now it blindly adds pageblock_nr_pages to the previous value. This causes the problem that isolation_start_pfn is larger than block_end_pfn when we isolate the page with more than pageblock order. In this case, isolation would fail due to an invalid range parameter. To prevent this, this patch implements skipping the range until a proper target pageblock is met. Without this patch, CMA with more than pageblock order always fails but with this patch it will succeed. Signed-off-by:
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