- 07 May, 2021 11 commits
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Wan Jiabing authored
Declaring struct pt_regs is unnecessary. On the one hand, there is no function using it; on the other hand, struct pt_regs has been declared in linux/kernel.h. Remove them. Link: https://lkml.kernel.org/r/20210401104834.1009157-1-wanjiabing@vivo.comSigned-off-by:
Wan Jiabing <wanjiabing@vivo.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andy Shevchenko authored
The bitmap.h header is used in a lot of code around the kernel. Besides that it includes kernel.h which sometimes makes a loop. The problem here is many unneeded loops that make header hell dependencies. For example, how may you move bitmap_zalloc() from C-file to the header? Currently it's impossible. And bitmap.h here is only the tip of an iceberg. kerne.h is a dump of everything that even has nothing in common at all. We may still have it, but in my new code I prefer to include only the headers that I want to use, without the bulk of unneeded kernel code. Break the loop by introducing align.h, including it in kernel.h and bitmap.h followed by replacing kernel.h with limits.h. Link: https://lkml.kernel.org/r/20210326170347.37441-1-andriy.shevchenko@linux.intel.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:
Yury Norov <yury.norov@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Matthew Wilcox (Oracle) authored
My UEK-derived config has 1030 files depending on pagemap.h before this change. Afterwards, just 326 files need to be rebuilt when I touch pagemap.h. I think blkdev.h is probably included too widely, but untangling that dependency is harder and this solves my problem. x86 allmodconfig builds, but there may be implicit include problems on other architectures. Link: https://lkml.kernel.org/r/20210309195747.283796-1-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Dan Williams <dan.j.williams@intel.com> [nvdimm] Acked-by: Jens Axboe <axboe@kernel.dk> [block] Reviewed-by:
Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Martin K. Petersen <martin.petersen@oracle.com> [scsi] Reviewed-by:
William Kucharski <william.kucharski@oracle.com> Signed-off-by:
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zhouchuangao authored
The function name should be modified to register_sysctl_paths instead of register_sysctl_table_path. Link: https://lkml.kernel.org/r/1615807194-79646-1-git-send-email-zhouchuangao@vivo.comSigned-off-by:
zhouchuangao <zhouchuangao@vivo.com> Signed-off-by:
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Alexey Dobriyan authored
Test that /proc instance mounted with mount -t proc -o subset=pid contains only ".", "..", "self", "thread-self" and pid directories. Note: Currently "subset=pid" doesn't return "." and ".." via readdir. This must be a bug. Link: https://lkml.kernel.org/r/YFYZZ7WGaZlsnChS@localhost.localdomainSigned-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Acked-by:
Alexey Gladkov <gladkov.alexey@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
Two checks in lookup and readdir code should be enough to not have third check in open code. Can't open what can't be looked up? Link: https://lkml.kernel.org/r/YFYYwIBIkytqnkxP@localhost.localdomainSigned-off-by:
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Alexey Dobriyan authored
Now that proc_ops are separate from file_operations and other operations it easy to check all instances to have ->proc_lseek hook and remove check in main code. Note: nonseekable_open() files naturally don't require ->proc_lseek. Garbage collect pde_lseek() function. [adobriyan@gmail.com: smoke test lseek()] Link: https://lkml.kernel.org/r/YG4OIhChOrVTPgdN@localhost.localdomain Link: https://lkml.kernel.org/r/YFYX0Bzwxlc7aBa/@localhost.localdomainSigned-off-by:
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Alexey Dobriyan authored
Can't look at this verbosity anymore. Link: https://lkml.kernel.org/r/YFYXAp/fgq405qcy@localhost.localdomainSigned-off-by:
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Colin Ian King authored
Currently the pde_is_permanent() check is being run on root multiple times rather than on the next proc directory entry. This looks like a copy-paste error. Fix this by replacing root with next. Addresses-Coverity: ("Copy-paste error") Link: https://lkml.kernel.org/r/20210318122633.14222-1-colin.king@canonical.com Fixes: d919b33d ("proc: faster open/read/close with "permanent" files") Signed-off-by:Colin Ian King <colin.king@canonical.com> Acked-by:
Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by:
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Randy Dunlap authored
Fix "no previous prototype" W=1 warnings from the kernel test robot: arch/alpha/lib/csum_partial_copy.c:349:1: error: no previous prototype for 'csum_and_copy_from_user' [-Werror=missing-prototypes] 349 | csum_and_copy_from_user(const void __user *src, void *dst, int len) | ^~~~~~~~~~~~~~~~~~~~~~~ arch/alpha/lib/csum_partial_copy.c:358:1: error: no previous prototype for 'csum_partial_copy_nocheck' [-Werror=missing-prototypes] 358 | csum_partial_copy_nocheck(const void *src, void *dst, int len) | ^~~~~~~~~~~~~~~~~~~~~~~~~ Link: https://lkml.kernel.org/r/20210425235749.19113-1-rdunlap@infradead.org Fixes: 808b49da ("alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()") Signed-off-by:Randy Dunlap <rdunlap@infradead.org> Reported-by:
kernel test robot <lkp@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by:
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Randy Dunlap authored
'make ARCH=alpha W=1' reports a couple of old-style function definitions with missing parameter list, so fix those. arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_base': arch/alpha/kernel/pc873xx.c:16:21: warning: old-style function definition [-Wold-style-definition] 16 | unsigned int __init pc873xx_get_base() arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_model': arch/alpha/kernel/pc873xx.c:21:14: warning: old-style function definition [-Wold-style-definition] 21 | char *__init pc873xx_get_model() Link: https://lkml.kernel.org/r/20210421061312.30097-1-rdunlap@infradead.orgSigned-off-by:
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- 05 May, 2021 29 commits
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Marco Elver authored
Use the power-efficient work queue, to avoid the pathological case where we keep pinning ourselves on the same possibly idle CPU on systems that want to be power-efficient (https://lwn.net/Articles/731052/). Link: https://lkml.kernel.org/r/20210421105132.3965998-4-elver@google.comSigned-off-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jann Horn <jannh@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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Marco Elver authored
The allocation wait timeout was initially added because of warnings due to CONFIG_DETECT_HUNG_TASK=y [1]. While the 1 sec timeout is sufficient to resolve the warnings (given the hung task timeout must be 1 sec or larger) it may cause unnecessary wake-ups if the system is idle: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com Fix it by computing the timeout duration in terms of the current sysctl_hung_task_timeout_secs value. Link: https://lkml.kernel.org/r/20210421105132.3965998-3-elver@google.comSigned-off-by:
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Marco Elver authored
Patch series "kfence: optimize timer scheduling", v2. We have observed that mostly-idle systems with KFENCE enabled wake up otherwise idle CPUs, preventing such to enter a lower power state. Debugging revealed that KFENCE spends too much active time in toggle_allocation_gate(). While the first version of KFENCE was using all the right bits to be scheduling optimal, and thus power efficient, by simply using wait_event() + wake_up(), that code was unfortunately removed. As KFENCE was exposed to various different configs and tests, the scheduling optimal code slowly disappeared. First because of hung task warnings, and finally because of deadlocks when an allocation is made by timer code with debug objects enabled. Clearly, the "fixes" were not too friendly for devices that want to be power efficient. Therefore, let's try a little harder to fix the hung task and deadlock problems that we have with wait_event() + wake_up(), while remaining as scheduling friendly and power efficient as possible. Crucially, we need to defer the wake_up() to an irq_work, avoiding any potential for deadlock. The result with this series is that on the devices where we observed a power regression, power usage returns back to baseline levels. This patch (of 3): On mostly-idle systems, we have observed that toggle_allocation_gate() is a cause of frequent wake-ups, preventing an otherwise idle CPU to go into a lower power state. A late change in KFENCE's development, due to a potential deadlock [1], required changing the scheduling-friendly wait_event_timeout() and wake_up() to an open-coded wait-loop using schedule_timeout(). [1] https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com To avoid unnecessary wake-ups, switch to using wait_event_timeout(). Unfortunately, we still cannot use a version with direct wake_up() in __kfence_alloc() due to the same potential for deadlock as in [1]. Instead, add a level of indirection via an irq_work that is scheduled if we determine that the kfence_timer requires a wake_up(). Link: https://lkml.kernel.org/r/20210421105132.3965998-1-elver@google.com Link: https://lkml.kernel.org/r/20210421105132.3965998-2-elver@google.com Fixes: 0ce20dd8 ("mm: add Kernel Electric-Fence infrastructure") Signed-off-by:
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Marco Elver authored
After an out-of-bounds accesses, zero the guard page before re-protecting in kfence_guarded_free(). On one hand this helps make the failure mode of subsequent out-of-bounds accesses more deterministic, but could also prevent certain information leaks. Link: https://lkml.kernel.org/r/20210312121653.348518-1-elver@google.comSigned-off-by:
Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by:
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Zhang Yunkai authored
'linux/compat.h' included in 'process_vm_access.c' is duplicated. Link: https://lkml.kernel.org/r/20210306132122.220431-1-zhang.yunkai@zte.com.cnSigned-off-by:
Zhang Yunkai <zhang.yunkai@zte.com.cn> Signed-off-by:
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Zhiyuan Dai authored
Various coding style tweaks to various files under mm/ [daizhiyuan@phytium.com.cn: mm/swapfile: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614223624-16055-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/sparse: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614227288-19363-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/vmscan: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614227649-19853-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/compaction: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228218-20770-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/oom_kill: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228360-21168-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/shmem: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228504-21491-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/page_alloc: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228613-21754-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/filemap: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228936-22337-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/mlock: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613956588-2453-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/frontswap: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613962668-15045-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/vmalloc: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613963379-15988-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/memory_hotplug: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613971784-24878-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/mempolicy: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613972228-25501-1-git-send-email-daizhiyuan@phytium.com.cn Link: https://lkml.kernel.org/r/1614222374-13805-1-git-send-email-daizhiyuan@phytium.com.cnSigned-off-by:
Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by:
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songqiang authored
Delete/add some blank lines and some blank spaces Link: https://lkml.kernel.org/r/20210311095015.14277-1-songqiang@uniontech.comSigned-off-by:
songqiang <songqiang@uniontech.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Signed-off-by:
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Ira Weiny authored
There are many places where kmap/memset/kunmap patterns occur. Use the newly lifted memzero_page() to eliminate direct uses of kmap and leverage the new core functions use of kmap_local_page(). The development of this patch was aided by the following coccinelle script: // <smpl> // SPDX-License-Identifier: GPL-2.0-only // Find kmap/memset/kunmap pattern and replace with memset*page calls // // NOTE: Offsets and other expressions may be more complex than what the script // will automatically generate. Therefore a catchall rule is provided to find // the pattern which then must be evaluated by hand. // // Confidence: Low // Copyright: (C) 2021 Intel Corporation // URL: http://coccinelle.lip6.fr/ // Comments: // Options: // // Then the memset pattern // @ memset_rule1 @ expression page, V, L, Off; identifier ptr; type VP; @@ ( -VP ptr = kmap(page); | -ptr = kmap(page); | -VP ptr = kmap_atomic(page); | -ptr = kmap_atomic(page); ) <+... ( -memset(ptr, 0, L); +memzero_page(page, 0, L); | -memset(ptr + Off, 0, L); +memzero_page(page, Off, L); | -memset(ptr, V, L); +memset_page(page, V, 0, L); | -memset(ptr + Off, V, L); +memset_page(page, V, Off, L); ) ...+> ( -kunmap(page); | -kunmap_atomic(ptr); ) // Remove any pointers left unused @ depends on memset_rule1 @ identifier memset_rule1.ptr; type VP, VP1; @@ -VP ptr; ... when != ptr; ? VP1 ptr; // // Catch all // @ memset_rule2 @ expression page; identifier ptr; expression GenTo, GenSize, GenValue; type VP; @@ ( -VP ptr = kmap(page); | -ptr = kmap(page); | -VP ptr = kmap_atomic(page); | -ptr = kmap_atomic(page); ) <+... ( // // Some call sites have complex expressions within the memset/memcpy // The follow are catch alls which need to be evaluated by hand. // -memset(GenTo, 0, GenSize); +memzero_pageExtra(page, GenTo, GenSize); | -memset(GenTo, GenValue, GenSize); +memset_pageExtra(page, GenValue, GenTo, GenSize); ) ...+> ( -kunmap(page); | -kunmap_atomic(ptr); ) // Remove any pointers left unused @ depends on memset_rule2 @ identifier memset_rule2.ptr; type VP, VP1; @@ -VP ptr; ... when != ptr; ? VP1 ptr; // </smpl> Link: https://lkml.kernel.org/r/20210309212137.2610186-4-ira.weiny@intel.comSigned-off-by:
Ira Weiny <ira.weiny@intel.com> Reviewed-by:
David Sterba <dsterba@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by:
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Ira Weiny authored
Patch series "btrfs: Convert kmap/memset/kunmap to memzero_user()". Lifting memzero_user(), convert it to kmap_local_page() and then use it in btrfs. This patch (of 3): memzero_page() can replace the kmap/memset/kunmap pattern in other places in the code. While zero_user() has the same interface it is not the same call and its use should be limited and some of those calls may be better converted from zero_user() to memzero_page().[1] But that is not addressed in this series. Lift memzero_page() to highmem. [1] https://lore.kernel.org/lkml/CAHk-=wijdojzo56FzYqE5TOYw2Vws7ik3LEMGj9SPQaJJ+Z73Q@mail.gmail.com/ Link: https://lkml.kernel.org/r/20210309212137.2610186-1-ira.weiny@intel.com Link: https://lkml.kernel.org/r/20210309212137.2610186-2-ira.weiny@intel.comSigned-off-by:
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zhouchuangao authored
It can be optimized at compile time. Link: https://lkml.kernel.org/r/1616727798-9110-1-git-send-email-zhouchuangao@vivo.comSigned-off-by:
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Zhiyuan Dai authored
strlcpy is marked as deprecated in Documentation/process/deprecated.rst, and there is no functional difference when the caller expects truncation (when not checking the return value). strscpy is relatively better as it also avoids scanning the whole source string. Link: https://lkml.kernel.org/r/1614227981-20367-1-git-send-email-daizhiyuan@phytium.com.cnSigned-off-by:
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Oscar Salvador authored
Enable arm64 platform to use the MHP_MEMMAP_ON_MEMORY feature. Link: https://lkml.kernel.org/r/20210421102701.25051-9-osalvador@suse.deSigned-off-by:
Oscar Salvador <osalvador@suse.de> Reviewed-by:
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Oscar Salvador authored
Enable x86_64 platform to use the MHP_MEMMAP_ON_MEMORY feature. Link: https://lkml.kernel.org/r/20210421102701.25051-8-osalvador@suse.deSigned-off-by:
Michal Hocko <mhocko@suse.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Oscar Salvador authored
Self stored memmap leads to a sparse memory situation which is unsuitable for workloads that requires large contiguous memory chunks, so make this an opt-in which needs to be explicitly enabled. To control this, let memory_hotplug have its own memory space, as suggested by David, so we can add memory_hotplug.memmap_on_memory parameter. Link: https://lkml.kernel.org/r/20210421102701.25051-7-osalvador@suse.deSigned-off-by:
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Oscar Salvador authored
Let the caller check whether it can pass MHP_MEMMAP_ON_MEMORY by checking mhp_supports_memmap_on_memory(). MHP_MEMMAP_ON_MEMORY can only be set in case ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE is enabled, the architecture supports altmap, and the range to be added spans a single memory block. Link: https://lkml.kernel.org/r/20210421102701.25051-6-osalvador@suse.deSigned-off-by:
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Oscar Salvador authored
Physical memory hotadd has to allocate a memmap (struct page array) for the newly added memory section. Currently, alloc_pages_node() is used for those allocations. This has some disadvantages: a) an existing memory is consumed for that purpose (eg: ~2MB per 128MB memory section on x86_64) This can even lead to extreme cases where system goes OOM because the physically hotplugged memory depletes the available memory before it is onlined. b) if the whole node is movable then we have off-node struct pages which has performance drawbacks. c) It might be there are no PMD_ALIGNED chunks so memmap array gets populated with base pages. This can be improved when CONFIG_SPARSEMEM_VMEMMAP is enabled. Vmemap page tables can map arbitrary memory. That means that we can reserve a part of the physically hotadded memory to back vmemmap page tables. This implementation uses the beginning of the hotplugged memory for that purpose. There are some non-obviously things to consider though. Vmemmap pages are allocated/freed during the memory hotplug events (add_memory_resource(), try_remove_memory()) when the memory is added/removed. This means that the reserved physical range is not online although it is used. The most obvious side effect is that pfn_to_online_page() returns NULL for those pfns. The current design expects that this should be OK as the hotplugged memory is considered a garbage until it is onlined. For example hibernation wouldn't save the content of those vmmemmaps into the image so it wouldn't be restored on resume but this should be OK as there no real content to recover anyway while metadata is reachable from other data structures (e.g. vmemmap page tables). The reserved space is therefore (de)initialized during the {on,off}line events (mhp_{de}init_memmap_on_memory). That is done by extracting page allocator independent initialization from the regular onlining path. The primary reason to handle the reserved space outside of {on,off}line_pages is to make each initialization specific to the purpose rather than special case them in a single function. As per above, the functions that are introduced are: - mhp_init_memmap_on_memory: Initializes vmemmap pages by calling move_pfn_range_to_zone(), calls kasan_add_zero_shadow(), and onlines as many sections as vmemmap pages fully span. - mhp_deinit_memmap_on_memory: Offlines as many sections as vmemmap pages fully span, removes the range from zhe zone by remove_pfn_range_from_zone(), and calls kasan_remove_zero_shadow() for the range. The new function memory_block_online() calls mhp_init_memmap_on_memory() before doing the actual online_pages(). Should online_pages() fail, we clean up by calling mhp_deinit_memmap_on_memory(). Adjusting of present_pages is done at the end once we know that online_pages() succedeed. On offline, memory_block_offline() needs to unaccount vmemmap pages from present_pages() before calling offline_pages(). This is necessary because offline_pages() tears down some structures based on the fact whether the node or the zone become empty. If offline_pages() fails, we account back vmemmap pages. If it succeeds, we call mhp_deinit_memmap_on_memory(). Hot-remove: We need to be careful when removing memory, as adding and removing memory needs to be done with the same granularity. To check that this assumption is not violated, we check the memory range we want to remove and if a) any memory block has vmemmap pages and b) the range spans more than a single memory block, we scream out loud and refuse to proceed. If all is good and the range was using memmap on memory (aka vmemmap pages), we construct an altmap structure so free_hugepage_table does the right thing and calls vmem_altmap_free instead of free_pagetable. Link: https://lkml.kernel.org/r/20210421102701.25051-5-osalvador@suse.deSigned-off-by: -
David Hildenbrand authored
Let's have a single place (inspired by adjust_managed_page_count()) where we adjust present pages. In contrast to adjust_managed_page_count(), only memory onlining or offlining is allowed to modify the number of present pages. Link: https://lkml.kernel.org/r/20210421102701.25051-4-osalvador@suse.deSigned-off-by:
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Oscar Salvador authored
We want {online,offline}_pages to operate on whole memblocks, but memmap_on_memory will poke pageblock_nr_pages aligned holes in the beginning, which is a special case we want to allow. Relax the check to account for that case. Link: https://lkml.kernel.org/r/20210421102701.25051-3-osalvador@suse.deSigned-off-by: -
Oscar Salvador authored
Patch series "Allocate memmap from hotadded memory (per device)", v10. The primary goal of this patchset is to reduce memory overhead of the hot-added memory (at least for SPARSEMEM_VMEMMAP memory model). The current way we use to populate memmap (struct page array) has two main drawbacks: a) it consumes an additional memory until the hotadded memory itself is onlined and b) memmap might end up on a different numa node which is especially true for movable_node configuration. c) due to fragmentation we might end up populating memmap with base pages One way to mitigate all these issues is to simply allocate memmap array (which is the largest memory footprint of the physical memory hotplug) from the hot-added memory itself. SPARSEMEM_VMEMMAP memory model allows us to map any pfn range so the memory doesn't need to be online to be usable for the array. See patch 4 for more details. This feature is only usable when CONFIG_SPARSEMEM_VMEMMAP is set. [Overall design]: Implementation wise we reuse vmem_altmap infrastructure to override the default allocator used by vmemap_populate. memory_block structure gains a new field called nr_vmemmap_pages, which accounts for the number of vmemmap pages used by that memory_block. E.g: On x86_64, that is 512 vmemmap pages on small memory bloks and 4096 on large memory blocks (1GB) We also introduce new two functions: memory_block_{online,offline}. These functions take care of initializing/unitializing vmemmap pages prior to calling {online,offline}_pages, so the latter functions can remain totally untouched. More details can be found in the respective changelogs. This patch (of 8): This is a preparatory patch that introduces two new functions: memory_block_online() and memory_block_offline(). For now, these functions will only call online_pages() and offline_pages() respectively, but they will be later in charge of preparing the vmemmap pages, carrying out the initialization and proper accounting of such pages. Since memory_block struct contains all the information, pass this struct down the chain till the end functions. Link: https://lkml.kernel.org/r/20210421102701.25051-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20210421102701.25051-2-osalvador@suse.deSigned-off-by: -
Mel Gorman authored
zone_pcp_reset allegedly protects against a race with drain_pages using local_irq_save but this is bogus. local_irq_save only operates on the local CPU. If memory hotplug is running on CPU A and drain_pages is running on CPU B, disabling IRQs on CPU A does not affect CPU B and offers no protection. This patch deletes IRQ disable/enable on the grounds that IRQs protect nothing and assumes the existing hotplug paths guarantees the PCP cannot be used after zone_pcp_enable(). That should be the case already because all the pages have been freed and there is no page to put on the PCP lists. Link: https://lkml.kernel.org/r/20210412090346.GQ3697@techsingularity.netSigned-off-by:
Mel Gorman <mgorman@techsingularity.net> Acked-by:
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Pavel Tatashin authored
When pages are pinned they can be faulted in userland and migrated, and they can be faulted right in kernel without migration. In either case, the pinned pages must end-up being pinnable (not movable). Add a new test to gup_test, to help verify that the gup/pup (get_user_pages() / pin_user_pages()) behavior with respect to pinnable and movable pages is reasonable and correct. Specifically, provide a way to: 1) Verify that only "pinnable" pages are pinned. This is checked automatically for you. 2) Verify that gup/pup performance is reasonable. This requires comparing benchmarks between doing gup/pup on pages that have been pre-faulted in from user space, vs. doing gup/pup on pages that are not faulted in until gup/pup time (via FOLL_TOUCH). This decision is controlled with the new -z command line option. Link: https://lkml.kernel.org/r/20210215161349.246722-15-pasha.tatashin@soleen.comSigned-off-by:
Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by:
John Hubbard <jhubbard@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Pavel Tatashin authored
In gup_test both gup_flags and test_flags use the same flags field. This is broken. Farther, in the actual gup_test.c all the passed gup_flags are erased and unconditionally replaced with FOLL_WRITE. Which means that test_flags are ignored, and code like this always performs pin dump test: 155 if (gup->flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN) 156 nr = pin_user_pages(addr, nr, gup->flags, 157 pages + i, NULL); 158 else 159 nr = get_user_pages(addr, nr, gup->flags, 160 pages + i, NULL); 161 break; Add a new test_flags field, to allow raw gup_flags to work. Add a new subcommand for DUMP_USER_PAGES_TEST to specify that pin test should be performed. Remove unconditional overwriting of gup_flags via FOLL_WRITE. But, preserve the previous behaviour where FOLL_WRITE was the default flag, and add a new option "-W" to unset FOLL_WRITE. Rename flags with gup_flags. With the fix, dump works like this: root@virtme:/# gup_test -c ---- page #0, starting from user virt addr: 0x7f8acb9e4000 page:00000000d3d2ee27 refcount:2 mapcount:1 mapping:0000000000000000 index:0x0 pfn:0x100bcf anon flags: 0x300000000080016(referenced|uptodate|lru|swapbacked) raw: 0300000000080016 ffffd0e204021608 ffffd0e208df2e88 ffff8ea04243ec61 raw: 0000000000000000 0000000000000000 0000000200000000 0000000000000000 page dumped because: gup_test: dump_pages() test DUMP_USER_PAGES_TEST: done root@virtme:/# gup_test -c -p ---- page #0, starting from user virt addr: 0x7fd19701b000 page:00000000baed3c7d refcount:1025 mapcount:1 mapping:0000000000000000 index:0x0 pfn:0x108008 anon flags: 0x300000000080014(uptodate|lru|swapbacked) raw: 0300000000080014 ffffd0e204200188 ffffd0e205e09088 ffff8ea04243ee71 raw: 0000000000000000 0000000000000000 0000040100000000 0000000000000000 page dumped because: gup_test: dump_pages() test DUMP_USER_PAGES_TEST: done Refcount shows the difference between pin vs no-pin case. Also change type of nr from int to long, as it counts number of pages. Link: https://lkml.kernel.org/r/20210215161349.246722-14-pasha.tatashin@soleen.comSigned-off-by:
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Pavel Tatashin authored
When pages are longterm pinned, we must migrated them out of movable zone. The function that migrates them has a hidden loop with goto. The loop is to retry on isolation failures, and after successful migration. Make this code better by moving this loop to the caller. Link: https://lkml.kernel.org/r/20210215161349.246722-13-pasha.tatashin@soleen.comSigned-off-by:
Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Pavel Tatashin authored
In __get_user_pages_locked() i counts number of pages which should be long, as long is used in all other places to contain number of pages, and 32-bit becomes increasingly small for handling page count proportional values. Link: https://lkml.kernel.org/r/20210215161349.246722-12-pasha.tatashin@soleen.comSigned-off-by:
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Pavel Tatashin authored
Document the special handling of page pinning when ZONE_MOVABLE present. Link: https://lkml.kernel.org/r/20210215161349.246722-11-pasha.tatashin@soleen.comSigned-off-by:
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Pavel Tatashin authored
We should not pin pages in ZONE_MOVABLE. Currently, we do not pin only movable CMA pages. Generalize the function that migrates CMA pages to migrate all movable pages. Use is_pinnable_page() to check which pages need to be migrated Link: https://lkml.kernel.org/r/20210215161349.246722-10-pasha.tatashin@soleen.comSigned-off-by:
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Pavel Tatashin authored
On some platforms ZERO_PAGE(0) might end-up in a movable zone. Do not migrate zero page in gup during longterm pinning as migration of zero page is not allowed. For example, in x86 QEMU with 16G of memory and kernelcore=5G parameter, I see the following: Boot#1: zero_pfn 0x48a8d zero_pfn zone: ZONE_DMA32 Boot#2: zero_pfn 0x20168d zero_pfn zone: ZONE_MOVABLE On x86, empty_zero_page is declared in .bss and depending on the loader may end up in different physical locations during boots. Also, move is_zero_pfn() my_zero_pfn() functions under CONFIG_MMU, because zero_pfn that they are using is declared in memory.c which is compiled with CONFIG_MMU. Link: https://lkml.kernel.org/r/20210215161349.246722-9-pasha.tatashin@soleen.comSigned-off-by:
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Pavel Tatashin authored
PF_MEMALLOC_PIN is only honored for CMA pages, extend this flag to work for any allocations from ZONE_MOVABLE by removing __GFP_MOVABLE from gfp_mask when this flag is passed in the current context. Add is_pinnable_page() to return true if page is in a pinnable page. A pinnable page is not in ZONE_MOVABLE and not of MIGRATE_CMA type. Link: https://lkml.kernel.org/r/20210215161349.246722-8-pasha.tatashin@soleen.comSigned-off-by:
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Pavel Tatashin authored
Function current_gfp_context() is called after fast path. However, soon we will add more constraints which will also limit zones based on context. Move this call into fast path, and apply the correct constraints for all allocations. Also update .reclaim_idx based on value returned by current_gfp_context() because it soon will modify the allowed zones. Note: With this patch we will do one extra current->flags load during fast path, but we already load current->flags in fast-path: __alloc_pages() prepare_alloc_pages() current_alloc_flags(gfp_mask, *alloc_flags); Later, when we add the zone constrain logic to current_gfp_context() we will be able to remove current->flags load from current_alloc_flags, and therefore return fast-path to the current performance level. Link: https://lkml.kernel.org/r/20210215161349.246722-7-pasha.tatashin@soleen.comSigned-off-by:
Michal Hocko <mhocko@kernel.org> Acked-by:
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