- 12 Sep, 2022 40 commits
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Miaohe Lin authored
When free_raw_hwp_pages() fails its work, the refcnt of the hugetlb page would have been incremented if ret > 0. Using put_page() to fix refcnt leaking in this case. Link: https://lkml.kernel.org/r/20220818130016.45313-3-linmiaohe@huawei.com Fixes: debb6b9c3fdd ("mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Acked-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Miaohe Lin authored
Patch series "A few fixup patches for memory-failure", v2. This series contains a few fixup patches to fix incorrect update of page refcnt, fix possible use-after-free issue and so on. More details can be found in the respective changelogs. This patch (of 6): When hwpoison_filter() refuses to hwpoison a hugetlb page, the refcnt of the page would have been incremented if res == 1. Using put_page() to fix the refcnt leaking in this case. Link: https://lkml.kernel.org/r/20220823032346.4260-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220818130016.45313-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220818130016.45313-2-linmiaohe@huawei.com Fixes: 405ce051 ("mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()") Signed-off-by:
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Charan Teja Kalla authored
The below is one path where race between page_ext and offline of the respective memory blocks will cause use-after-free on the access of page_ext structure. process1 process2 --------- --------- a)doing /proc/page_owner doing memory offline through offline_pages. b) PageBuddy check is failed thus proceed to get the page_owner information through page_ext access. page_ext = lookup_page_ext(page); migrate_pages(); ................. Since all pages are successfully migrated as part of the offline operation,send MEM_OFFLINE notification where for page_ext it calls: offline_page_ext()--> __free_page_ext()--> free_page_ext()--> vfree(ms->page_ext) mem_section->page_ext = NULL c) Check for the PAGE_EXT flags in the page_ext->flags access results into the use-after-free (leading to the translation faults). As mentioned above, there is really no synchronization between page_ext access and its freeing in the memory_offline. The memory offline steps(roughly) on a memory block is as below: 1) Isolate all the pages 2) while(1) try free the pages to buddy.(->free_list[MIGRATE_ISOLATE]) 3) delete the pages from this buddy list. 4) Then free page_ext.(Note: The struct page is still alive as it is freed only during hot remove of the memory which frees the memmap, which steps the user might not perform). This design leads to the state where struct page is alive but the struct page_ext is freed, where the later is ideally part of the former which just representing the page_flags (check [3] for why this design is chosen). The abovementioned race is just one example __but the problem persists in the other paths too involving page_ext->flags access(eg: page_is_idle())__. Fix all the paths where offline races with page_ext access by maintaining synchronization with rcu lock and is achieved in 3 steps: 1) Invalidate all the page_ext's of the sections of a memory block by storing a flag in the LSB of mem_section->page_ext. 2) Wait until all the existing readers to finish working with the ->page_ext's with synchronize_rcu(). Any parallel process that starts after this call will not get page_ext, through lookup_page_ext(), for the block parallel offline operation is being performed. 3) Now safely free all sections ->page_ext's of the block on which offline operation is being performed. Note: If synchronize_rcu() takes time then optimizations can be done in this path through call_rcu()[2]. Thanks to David Hildenbrand for his views/suggestions on the initial discussion[1] and Pavan kondeti for various inputs on this patch. [1] https://lore.kernel.org/linux-mm/59edde13-4167-8550-86f0-11fc67882107@quicinc.com/ [2] https://lore.kernel.org/all/a26ce299-aed1-b8ad-711e-a49e82bdd180@quicinc.com/T/#u [3] https://lore.kernel.org/all/6fa6b7aa-731e-891c-3efb-a03d6a700efa@redhat.com/ [quic_charante@quicinc.com: rename label `loop' to `ext_put_continue' per David] Link: https://lkml.kernel.org/r/1661496993-11473-1-git-send-email-quic_charante@quicinc.com Link: https://lkml.kernel.org/r/1660830600-9068-1-git-send-email-quic_charante@quicinc.comSigned-off-by:
Charan Teja Kalla <quic_charante@quicinc.com> Suggested-by:
David Hildenbrand <david@redhat.com> Suggested-by:
Michal Hocko <mhocko@suse.com> Acked-by:
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Matthew Wilcox authored
If the pages being mapped are in HIGHMEM, page_address() returns NULL. This probably wasn't noticed before because there aren't currently any architectures with HAVE_ARCH_HUGE_VMALLOC and HIGHMEM, but it's simpler to call page_to_phys() and futureproofs us against such configurations existing. Link: https://lkml.kernel.org/r/Yv6qHc6e+m7TMWhi@casper.infradead.org Fixes: 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
William Kucharski <william.kucharski@oracle.com> Reviewed-by:
Christoph Hellwig <hch@lst.de> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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xupanda authored
Fix a spelling mistake in comment. Link: https://lkml.kernel.org/r/20220815065102.74347-1-xu.panda@zte.com.cnReported-by:
Zeal Robot <zealci@zte.com.cn> Signed-off-by:
xupanda <xu.panda@zte.com.cn> Signed-off-by:
CGEL ZTE <cgel.zte@gmail.com> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
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Kefeng Wang authored
find_min_pfn_with_active_regions() is only called from free_area_init(). Open-code the PHYS_PFN(memblock_start_of_DRAM()) into free_area_init(), and kill find_min_pfn_with_active_regions(). Link: https://lkml.kernel.org/r/20220815111017.39341-1-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by:
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Zi Yan authored
This Kconfig option is used by individual arch to set its desired MAX_ORDER. Rename it to reflect its actual use. Link: https://lkml.kernel.org/r/20220815143959.1511278-1-zi.yan@sent.comAcked-by:
Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
Zi Yan <ziy@nvidia.com> Acked-by: Guo Ren <guoren@kernel.org> [csky] Acked-by:
Arnd Bergmann <arnd@arndb.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Huacai Chen <chenhuacai@kernel.org> [LoongArch] Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Neil Armstrong <narmstrong@baylibre.com> Cc: Qin Jian <qinjian@cqplus1.com> Cc: Guo Ren <guoren@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Zankel <chris@zankel.net> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Signed-off-by:
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Alexey Romanov authored
Emails are not documentation. [akpm@linux-foundation.org: fix whitespace damage, repair doc reference] [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/20220815144825.39001-1-avromanov@sberdevices.ruSigned-off-by:
Alexey Romanov <avromanov@sberdevices.ru> Reviewed-by:
Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by:
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Miaohe Lin authored
If the pagetables are shared, we shouldn't copy or take references. Since src could have unshared and dst shares with another vma, huge_pte_none() is thus used to determine whether dst_pte is shared. But this check isn't reliable. A shared pte could have pte none in pagetable in fact. The page count of ptep page should be checked here in order to reliably determine whether pte is shared. [lukas.bulwahn@gmail.com: remove unused local variable dst_entry in copy_hugetlb_page_range()] Link: https://lkml.kernel.org/r/20220822082525.26071-1-lukas.bulwahn@gmail.com Link: https://lkml.kernel.org/r/20220816130553.31406-7-linmiaohe@huawei.comSigned-off-by:
Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Miaohe Lin authored
The sysfs group per_node_hstate_attr_group and hstate_demote_attr_group when h->demote_order != 0 are created in hugetlb_register_node(). But these sysfs groups are not removed when unregister the node, thus sysfs group is leaked. Using sysfs_remove_group() to fix this issue. Link: https://lkml.kernel.org/r/20220816130553.31406-6-linmiaohe@huawei.comSigned-off-by:
Fengwei Yin <fengwei.yin@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Miaohe Lin authored
The memory barrier smp_wmb() is needed to make sure that preceding stores to the page contents become visible before the below set_pte_at() write. Link: https://lkml.kernel.org/r/20220816130553.31406-5-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
When huge_add_to_page_cache() fails, the page is freed directly without calling restore_reserve_on_error() to restore reserve for newly allocated pages not in page cache. Fix this by calling restore_reserve_on_error() when huge_add_to_page_cache fails. [linmiaohe@huawei.com: remove err == -EEXIST check and retry logic] Link: https://lkml.kernel.org/r/20220823030209.57434-4-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220816130553.31406-4-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
If sysfs_create_group() fails with hstate_attr_group, hstate_kobjs[hi] will be set to NULL. Then it will be passed to sysfs_create_group() if h->demote_order != 0 thus triggering WARN_ON(!kobj) check. Fix this by making sure hstate_kobjs[hi] != NULL when calling sysfs_create_group. Link: https://lkml.kernel.org/r/20220816130553.31406-3-linmiaohe@huawei.com Fixes: 79dfc695 ("hugetlb: add demote hugetlb page sysfs interfaces") Signed-off-by:
Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Miaohe Lin authored
Patch series "A few fixup patches for hugetlb". This series contains a few fixup patches to fix incorrect update of max_huge_pages, fix WARN_ON(!kobj) in sysfs_create_group() and so on. More details can be found in the respective changelogs. This patch (of 6): There should be pages_per_huge_page(h) / pages_per_huge_page(target_hstate) pages incremented for target_hstate->max_huge_pages when page is demoted. Update max_huge_pages accordingly for consistency. Link: https://lkml.kernel.org/r/20220816130553.31406-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220816130553.31406-2-linmiaohe@huawei.comSigned-off-by:
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Huang Ying authored
The promotion hot threshold is workload and system configuration dependent. So in this patch, a method to adjust the hot threshold automatically is implemented. The basic idea is to control the number of the candidate promotion pages to match the promotion rate limit. If the hint page fault latency of a page is less than the hot threshold, we will try to promote the page, and the page is called the candidate promotion page. If the number of the candidate promotion pages in the statistics interval is much more than the promotion rate limit, the hot threshold will be decreased to reduce the number of the candidate promotion pages. Otherwise, the hot threshold will be increased to increase the number of the candidate promotion pages. To make the above method works, in each statistics interval, the total number of the pages to check (on which the hint page faults occur) and the hot/cold distribution need to be stable. Because the page tables are scanned linearly in NUMA balancing, but the hot/cold distribution isn't uniform along the address usually, the statistics interval should be larger than the NUMA balancing scan period. So in the patch, the max scan period is used as statistics interval and it works well in our tests. Link: https://lkml.kernel.org/r/20220713083954.34196-4-ying.huang@intel.comSigned-off-by:
"Huang, Ying" <ying.huang@intel.com> Reviewed-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by:
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Huang Ying authored
In NUMA balancing memory tiering mode, if there are hot pages in slow memory node and cold pages in fast memory node, we need to promote/demote hot/cold pages between the fast and cold memory nodes. A choice is to promote/demote as fast as possible. But the CPU cycles and memory bandwidth consumed by the high promoting/demoting throughput will hurt the latency of some workload because of accessing inflating and slow memory bandwidth contention. A way to resolve this issue is to restrict the max promoting/demoting throughput. It will take longer to finish the promoting/demoting. But the workload latency will be better. This is implemented in this patch as the page promotion rate limit mechanism. The number of the candidate pages to be promoted to the fast memory node via NUMA balancing is counted, if the count exceeds the limit specified by the users, the NUMA balancing promotion will be stopped until the next second. A new sysctl knob kernel.numa_balancing_promote_rate_limit_MBps is added for the users to specify the limit. Link: https://lkml.kernel.org/r/20220713083954.34196-3-ying.huang@intel.comSigned-off-by:
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Huang Ying authored
Patch series "memory tiering: hot page selection", v4. To optimize page placement in a memory tiering system with NUMA balancing, the hot pages in the slow memory nodes need to be identified. Essentially, the original NUMA balancing implementation selects the mostly recently accessed (MRU) pages to promote. But this isn't a perfect algorithm to identify the hot pages. Because the pages with quite low access frequency may be accessed eventually given the NUMA balancing page table scanning period could be quite long (e.g. 60 seconds). So in this patchset, we implement a new hot page identification algorithm based on the latency between NUMA balancing page table scanning and hint page fault. Which is a kind of mostly frequently accessed (MFU) algorithm. In NUMA balancing memory tiering mode, if there are hot pages in slow memory node and cold pages in fast memory node, we need to promote/demote hot/cold pages between the fast and cold memory nodes. A choice is to promote/demote as fast as possible. But the CPU cycles and memory bandwidth consumed by the high promoting/demoting throughput will hurt the latency of some workload because of accessing inflating and slow memory bandwidth contention. A way to resolve this issue is to restrict the max promoting/demoting throughput. It will take longer to finish the promoting/demoting. But the workload latency will be better. This is implemented in this patchset as the page promotion rate limit mechanism. The promotion hot threshold is workload and system configuration dependent. So in this patchset, a method to adjust the hot threshold automatically is implemented. The basic idea is to control the number of the candidate promotion pages to match the promotion rate limit. We used the pmbench memory accessing benchmark tested the patchset on a 2-socket server system with DRAM and PMEM installed. The test results are as follows, pmbench score promote rate (accesses/s) MB/s ------------- ------------ base 146887704.1 725.6 hot selection 165695601.2 544.0 rate limit 162814569.8 165.2 auto adjustment 170495294.0 136.9 From the results above, With hot page selection patch [1/3], the pmbench score increases about 12.8%, and promote rate (overhead) decreases about 25.0%, compared with base kernel. With rate limit patch [2/3], pmbench score decreases about 1.7%, and promote rate decreases about 69.6%, compared with hot page selection patch. With threshold auto adjustment patch [3/3], pmbench score increases about 4.7%, and promote rate decrease about 17.1%, compared with rate limit patch. Baolin helped to test the patchset with MySQL on a machine which contains 1 DRAM node (30G) and 1 PMEM node (126G). sysbench /usr/share/sysbench/oltp_read_write.lua \ ...... --tables=200 \ --table-size=1000000 \ --report-interval=10 \ --threads=16 \ --time=120 The tps can be improved about 5%. This patch (of 3): To optimize page placement in a memory tiering system with NUMA balancing, the hot pages in the slow memory node need to be identified. Essentially, the original NUMA balancing implementation selects the mostly recently accessed (MRU) pages to promote. But this isn't a perfect algorithm to identify the hot pages. Because the pages with quite low access frequency may be accessed eventually given the NUMA balancing page table scanning period could be quite long (e.g. 60 seconds). The most frequently accessed (MFU) algorithm is better. So, in this patch we implemented a better hot page selection algorithm. Which is based on NUMA balancing page table scanning and hint page fault as follows, - When the page tables of the processes are scanned to change PTE/PMD to be PROT_NONE, the current time is recorded in struct page as scan time. - When the page is accessed, hint page fault will occur. The scan time is gotten from the struct page. And The hint page fault latency is defined as hint page fault time - scan time The shorter the hint page fault latency of a page is, the higher the probability of their access frequency to be higher. So the hint page fault latency is a better estimation of the page hot/cold. It's hard to find some extra space in struct page to hold the scan time. Fortunately, we can reuse some bits used by the original NUMA balancing. NUMA balancing uses some bits in struct page to store the page accessing CPU and PID (referring to page_cpupid_xchg_last()). Which is used by the multi-stage node selection algorithm to avoid to migrate pages shared accessed by the NUMA nodes back and forth. But for pages in the slow memory node, even if they are shared accessed by multiple NUMA nodes, as long as the pages are hot, they need to be promoted to the fast memory node. So the accessing CPU and PID information are unnecessary for the slow memory pages. We can reuse these bits in struct page to record the scan time. For the fast memory pages, these bits are used as before. For the hot threshold, the default value is 1 second, which works well in our performance test. All pages with hint page fault latency < hot threshold will be considered hot. It's hard for users to determine the hot threshold. So we don't provide a kernel ABI to set it, just provide a debugfs interface for advanced users to experiment. We will continue to work on a hot threshold automatic adjustment mechanism. The downside of the above method is that the response time to the workload hot spot changing may be much longer. For example, - A previous cold memory area becomes hot - The hint page fault will be triggered. But the hint page fault latency isn't shorter than the hot threshold. So the pages will not be promoted. - When the memory area is scanned again, maybe after a scan period, the hint page fault latency measured will be shorter than the hot threshold and the pages will be promoted. To mitigate this, if there are enough free space in the fast memory node, the hot threshold will not be used, all pages will be promoted upon the hint page fault for fast response. Thanks Zhong Jiang reported and tested the fix for a bug when disabling memory tiering mode dynamically. Link: https://lkml.kernel.org/r/20220713083954.34196-1-ying.huang@intel.com Link: https://lkml.kernel.org/r/20220713083954.34196-2-ying.huang@intel.comSigned-off-by: -
Kefeng Wang authored
If a process has not enough memory to allocate a new virtual mapping, we may meet verious kinds of error, eg, fork cannot allocate memory, SIGBUS error in shmem, but it is difficult to confirm them, let's add some debug information to easily to check this scenario if __vm_enough_memory fails. Link: https://lkml.kernel.org/r/20220726145428.8030-1-wangkefeng.wang@huawei.comReported-by:
Yongqiang Liu <liuyongqiang13@huawei.com> Signed-off-by:
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Peter Collingbourne authored
gfp_migratetype() also expects GFP_RECLAIMABLE and GFP_MOVABLE|GFP_RECLAIMABLE to be shiftable into MIGRATE_* enum values, so add some more BUILD_BUG_ONs to reflect this assumption. Link: https://linux-review.googlesource.com/id/Iae64e2182f75c3aca776a486b71a72571d66d83e Link: https://lkml.kernel.org/r/20220726230241.3770532-1-pcc@google.comSigned-off-by:
Peter Collingbourne <pcc@google.com> Signed-off-by:
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Alistair Popple authored
When pinning pages with FOLL_LONGTERM check_and_migrate_movable_pages() is called to migrate pages out of zones which should not contain any longterm pinned pages. When migration succeeds all pages will have been unpinned so pinning needs to be retried. This is indicated by returning zero. When all pages are in the correct zone the number of pinned pages is returned. However migration can also fail, in which case pages are unpinned and -ENOMEM is returned. However if the failure was due to not being unable to isolate a page zero is returned. This leads to indefinite looping in __gup_longterm_locked(). Fix this by simplifying the return codes such that zero indicates all pages were successfully pinned in the correct zone while errors indicate either pages were migrated and pinning should be retried or that migration has failed and therefore the pinning operation should fail. [syoshida@redhat.com: fix return value for __gup_longterm_locked()] Link: https://lkml.kernel.org/r/20220821183547.950370-1-syoshida@redhat.com [akpm@linux-foundation.org: fix code layout, per John] [yshigeru@gmail.com: fix uninitialized return value on __gup_longterm_locked()] Link: https://lkml.kernel.org/r/20220827230037.78876-1-syoshida@redhat.com Link: https://lkml.kernel.org/r/20220729024645.764366-1-apopple@nvidia.comSigned-off-by:
Alistair Popple <apopple@nvidia.com> Signed-off-by:
Shigeru Yoshida <syoshida@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by:
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Miaohe Lin authored
Use helper for_each_hstate and hstate_index to iterate the hstate and get the hstate index. Minor readability improvement. Link: https://lkml.kernel.org/r/20220729080106.12752-6-linmiaohe@huawei.comSigned-off-by:
Mina Almasry <almasrymina@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Miaohe Lin authored
It's better to use NUMA_NO_NODE instead of magic number -1. Minor readability improvement. Link: https://lkml.kernel.org/r/20220729080106.12752-5-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
The return value of set_hugetlb_cgroup and set_hugetlb_cgroup_rsvd are always ignored. Remove them to clean up the code. Link: https://lkml.kernel.org/r/20220729080106.12752-4-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Use helper macro SZ_1K, SZ_1M and SZ_1G to do the size conversion. Minor readability improvement. Link: https://lkml.kernel.org/r/20220729080106.12752-3-linmiaohe@huawei.comSigned-off-by:
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Miaohe Lin authored
Patch series "A few cleanup patches for hugetlb_cgroup", v2. This series contains a few cleaup patches to remove unneeded check, use helper macro, remove unneeded return value and so on. More details can be found in the respective changelogs. This patch (of 5): When code reaches here, nr_pages must be > 0. Remove unneeded nr_pages > 0 check to simplify the code. Link: https://lkml.kernel.org/r/20220729080106.12752-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220729080106.12752-2-linmiaohe@huawei.comSigned-off-by:
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Tarun Sahu authored
libhugetlbfs, the user side utitlity to work with hugepages, does not have any active support. There are only 2 selftests which are part of in vm/hmm_test.c that depends on libhugetlbfs. This patch modifies the tests so that they will not require libhugetlb library. [axelrasmussen@google.com: : remove orphaned references to local_config.{h,mk}] Link: https://lkml.kernel.org/r/20220831211526.2743216-1-axelrasmussen@google.com Link: https://lkml.kernel.org/r/20220801070231.13831-1-tsahu@linux.ibm.comSigned-off-by:Tarun Sahu <tsahu@linux.ibm.com> Signed-off-by:
Axel Rasmussen <axelrasmussen@google.com> Tested-by:
Zach O'Keefe <zokeefe@google.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Shivaprasad G Bhat <sbhat@linux.ibm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Signed-off-by:
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Imran Khan authored
By default kfence allocation can happen for any slab object, whose size is up to PAGE_SIZE, as long as that allocation is the first allocation after expiration of kfence sample interval. But in certain debugging scenarios we may be interested in debugging corruptions involving some specific slub objects like dentry or ext4_* etc. In such cases limiting kfence for allocations involving only specific slub objects will increase the probablity of catching the issue since kfence pool will not be consumed by other slab objects. This patch introduces a sysfs interface '/sys/kernel/slab/<name>/skip_kfence' to disable kfence for specific slabs. Having the interface work in this way does not impact current/default behavior of kfence and allows us to use kfence for specific slabs (when needed) as well. The decision to skip/use kfence is taken depending on whether kmem_cache.flags has (newly introduced) SLAB_SKIP_KFENCE flag set or not. Link: https://lkml.kernel.org/r/20220814195353.2540848-1-imran.f.khan@oracle.comSigned-off-by:
Imran Khan <imran.f.khan@oracle.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Marco Elver <elver@google.com> Reviewed-by:
Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by:
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Haiyue Wang authored
Not all huge page APIs support FOLL_GET option, so move_pages() syscall will fail to get the page node information for some huge pages. Like x86 on linux 5.19 with 1GB huge page API follow_huge_pud(), it will return NULL page for FOLL_GET when calling move_pages() syscall with the NULL 'nodes' parameter, the 'status' parameter has '-2' error in array. Note: follow_huge_pud() now supports FOLL_GET in linux 6.0. Link: https://lore.kernel.org/all/20220714042420.1847125-3-naoya.horiguchi@linux.dev But these huge page APIs don't support FOLL_GET: 1. follow_huge_pud() in arch/s390/mm/hugetlbpage.c 2. follow_huge_addr() in arch/ia64/mm/hugetlbpage.c It will cause WARN_ON_ONCE for FOLL_GET. 3. follow_huge_pgd() in mm/hugetlb.c This is an temporary solution to mitigate the side effect of the race condition fix by calling follow_page() with FOLL_GET set for huge pages. After supporting follow huge page by FOLL_GET is done, this fix can be reverted safely. Link: https://lkml.kernel.org/r/20220823135841.934465-2-haiyue.wang@intel.com Link: https://lkml.kernel.org/r/20220812084921.409142-1-haiyue.wang@intel.com Fixes: 4cd61484 ("mm: migration: fix possible do_pages_stat_array racing with memory offline") Signed-off-by:Haiyue Wang <haiyue.wang@intel.com> Reviewed-by:
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Yang Yang authored
After patch "mm/workingset: prepare the workingset detection infrastructure for anon LRU", we can handle the refaults of anonymous pages too. So the annotations of refaults should cover both of anonymous pages and file pages. Link: https://lkml.kernel.org/r/20220813080757.59131-1-yang.yang29@zte.com.cn Fixes: 170b04b7 ("mm/workingset: prepare the workingset detection infrastructure for anon LRU") Signed-off-by:
Yang Yang <yang.yang29@zte.com.cn> Signed-off-by:
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Kaixu Xia authored
The parameter 'struct damon_ctx *ctx' is unnecessary in damon region split operation, so we can remove it. Link: https://lkml.kernel.org/r/1660403943-29124-1-git-send-email-kaixuxia@tencent.comSigned-off-by:
Kaixu Xia <kaixuxia@tencent.com> Reviewed-by:
SeongJae Park <sj@kernel.org> Signed-off-by:
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Yixuan Cao authored
The -f option is to filter out the information of blocks whose memory has not been released, I noticed some blocks should not be filtered out. Commit 9cc7e96a ("mm/page_owner: record timestamp and pid") records the allocation timestamp (ts_nsec) of all pages. Commit 866b4852 ("mm/page_owner: record the timestamp of all pages during free") records the free timestamp (free_ts_nsec) of all pages. When the page is allocated for the first time, the initial value of free_ts_nsec is 0, and the corresponding time will be obtained when the page is released. But during reallocation the free_ts_nsec will not reset to 0 again. In particular, when page migration occurs, these two timestamps will be the same. Now page_owner_sort removes all text blocks whose free_ts_nsec is not 0 when using -f option. However, this way can only select pages allocated for the first time. If a freed page is reallocated, free_ts_nsec will be less than ts_nsec; if page migration occurs, the two timestamps will be equal. These cases should be considered as pages are not released. So I fix the function is_need() to keep text blocks that meet the above two conditions when using -f option. Link: https://lkml.kernel.org/r/20220812155515.30846-1-caoyixuan2019@email.szu.edu.cnSigned-off-by:
Yixuan Cao <caoyixuan2019@email.szu.edu.cn> Cc: Chongxi Zhao <zhaochongxi2019@email.szu.edu.cn> Cc: Jiajian Ye <yejiajian2018@email.szu.edu.cn> Cc: Yuhong Feng <yuhongf@szu.edu.cn> Cc: Liam Mark <lmark@codeaurora.org> Cc: Georgi Djakov <georgi.djakov@linaro.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Kairui Song authored
folio_test_hugetlb() will call PageHeadHuge which is a function call, and blocks the compiler from recognizing this redundant load. After rearranging the code, stack usage is dropped from 32 to 24, and the function size is smaller (tested on GCC 12): Before: Stack usage: mm/util.c:845:5:folio_mapcount 32 static Size: 0000000000000ea0 00000000000000c7 T folio_mapcount After: Stack usage: mm/util.c:845:5:folio_mapcount 24 static Size: 0000000000000ea0 00000000000000b0 T folio_mapcount Link: https://lkml.kernel.org/r/20220801173155.92008-1-ryncsn@gmail.comSigned-off-by:
Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by:
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Abel Wu authored
It seems unnecessary to search pages with order < alloc_order in fallback allocation. This can currently happen with ALLOC_NOFRAGMENT and alloc_order > pageblock_order, so add a test to prevent it. [vbabka@suse.cz: changelog addition] Link: https://lkml.kernel.org/r/20220803025121.47018-1-wuyun.abel@bytedance.comSigned-off-by:
Abel Wu <wuyun.abel@bytedance.com> Acked-by:
Mel Gorman <mgorman@techsingularity.net> Reviewed-by:
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Li kunyu authored
The allocation address of the table pointer variable is first performed in the function, no initialization assignment is required, and no invalid pointer will appear. Link: https://lkml.kernel.org/r/20220803064118.3664-1-kunyu@nfschina.comSigned-off-by:
Li kunyu <kunyu@nfschina.com> Signed-off-by:
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Feng Tang authored
Muchun Song found that after MPOL_PREFERRED_MANY policy was introduced in commit b27abacc ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes"), the policy_nodemask_current()'s semantics for this new policy has been changed, which returns 'preferred' nodes instead of 'allowed' nodes. With the changed semantic of policy_nodemask_current, a task with MPOL_PREFERRED_MANY policy could fail to get its reservation even though it can fall back to other nodes (either defined by cpusets or all online nodes) for that reservation failing mmap calles unnecessarily early. The fix is to not consider MPOL_PREFERRED_MANY for reservations at all because they, unlike MPOL_MBIND, do not pose any actual hard constrain. Michal suggested the policy_nodemask_current() is only used by hugetlb, and could be moved to hugetlb code with more explicit name to enforce the 'allowed' semantics for which only MPOL_BIND policy matters. apply_policy_zone() is made extern to be called in hugetlb code and its return value is changed to bool. [1]. https://lore.kernel.org/lkml/20220801084207.39086-1-songmuchun@bytedance.com/t/ Link: https://lkml.kernel.org/r/20220805005903.95563-1-feng.tang@intel.com Fixes: b27abacc ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple preferred nodes") Signed-off-by:
Feng Tang <feng.tang@intel.com> Reported-by:
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Abel Wu authored
The mems_allowed field can be modified by other tasks, so it isn't safe to access it with alloc_lock unlocked even in the current process context. Say there are two tasks: A from cpusetA is performing set_mempolicy(2), and B is changing cpusetA's cpuset.mems: A (set_mempolicy) B (echo xx > cpuset.mems) ------------------------------------------------------- pol = mpol_new(); update_tasks_nodemask(cpusetA) { foreach t in cpusetA { cpuset_change_task_nodemask(t) { mpol_set_nodemask(pol) { task_lock(t); // t could be A new = f(A->mems_allowed); update t->mems_allowed; pol.create(pol, new); task_unlock(t); } } } } task_lock(A); A->mempolicy = pol; task_unlock(A); In this case A's pol->nodes is computed by old mems_allowed, and could be inconsistent with A's new mems_allowed. While it is different when replacing vmas' policy: the pol->nodes is gone wild only when current_cpuset_is_being_rebound(): A (mbind) B (echo xx > cpuset.mems) ------------------------------------------------------- pol = mpol_new(); mmap_write_lock(A->mm); cpuset_being_rebound = cpusetA; update_tasks_nodemask(cpusetA) { foreach t in cpusetA { cpuset_change_task_nodemask(t) { mpol_set_nodemask(pol) { task_lock(t); // t could be A mask = f(A->mems_allowed); update t->mems_allowed; pol.create(pol, mask); task_unlock(t); } } foreach v in A->mm { if (cpuset_being_rebound == cpusetA) pol.rebind(pol, cpuset.mems); v->vma_policy = pol; } mmap_write_unlock(A->mm); mmap_write_lock(t->mm); mpol_rebind_mm(t->mm); mmap_write_unlock(t->mm); } } cpuset_being_rebound = NULL; In this case, the cpuset.mems, which has already done updating, is finally used for calculating pol->nodes, rather than A->mems_allowed. So it is OK to call mpol_set_nodemask() with alloc_lock unlocked when doing mbind(2). Link: https://lkml.kernel.org/r/20220811124157.74888-1-wuyun.abel@bytedance.com Fixes: 78b132e9 ("mm/mempolicy: remove or narrow the lock on current") Signed-off-by:Wei Yang <richard.weiyang@gmail.com> Reviewed-by:
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Charan Teja Kalla authored
Currently only 12 characters of the cma name is being used as the debug directories where as the cma name can be of length CMA_MAX_NAME(=64) characters. One side problem with this is having 2 cma's with first common 12 characters would end up in trying to create directories with same name and fails with -EEXIST thus can limit cma debug functionality. The 'cma-' prefix is used initially where cma areas don't have any names and are represented by simple integer values. Since now each cma would be having its own name, drop 'cma-' prefix for the cma debug directories as they are clearly evident that they are for cma debug through creating them in /sys/kernel/debug/cma/ path. Link: https://lkml.kernel.org/r/1660223729-22461-1-git-send-email-quic_charante@quicinc.comSigned-off-by:
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Christoph Hellwig authored
The argument is always set to end_swap_bio_write, so remove the argument and mark end_swap_bio_write static. Link: https://lkml.kernel.org/r/20220811141741.660214-1-hch@lst.deSigned-off-by:
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Alexey Romanov authored
pool->size_class array elements can't be NULL, so this check is not needed. In the whole code, we assign pool->size_class[i] values that are not NULL. Releasing memory for these values occurs in the zs_destroy_pool() function, which also releases and destroys the pool. In addition, in the zs_stats_size_show() and async_free_zspage(), with similar iterations over the array, we don't check it for NULL pointer. Link: https://lkml.kernel.org/r/20220811153755.16102-3-avromanov@sberdevices.ruSigned-off-by:
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Alexey Romanov authored
Patch series "tidy up zsmalloc implementation" This patchset remove some unnecessary checks and adds a clarifying comment. While analysing zs_object_copy() function code, I spent some time to understand what the call kunmap_atomic(d_addr) is for. It seems that this point is not trivial and it is worth adding a comment. This patch (of 2): It's not obvious why kunmap_atomic(d_addr) call is needed. [akpm@linux-foundation.org: tweak comment layout] Link: https://lkml.kernel.org/r/20220811153755.16102-1-avromanov@sberdevices.ru Link: https://lkml.kernel.org/r/20220811153755.16102-2-avromanov@sberdevices.ruSigned-off-by:
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