The patch titled Subject: Re: mm: mkfs.ext4 invoked oom-killer on i386 - pagecache_get_page has been added to the -mm tree. Its filename is mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control-fix-v2.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control-fix-v2.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control-fix-v2.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Johannes Weiner <hannes@xxxxxxxxxxx> Subject: Re: mm: mkfs.ext4 invoked oom-killer on i386 - pagecache_get_page Fix crash with cgroup_disable=memory: > > > > + mkfs -t ext4 /dev/disk/by-id/ata-TOSHIBA_MG04ACA100N_Y8NRK0BPF6XF > > > > mke2fs 1.43.8 (1-Jan-2018) > > > > Creating filesystem with 244190646 4k blocks and 61054976 inodes > > > > Filesystem UUID: 3bb1a285-2cb4-44b4-b6e8-62548f3ac620 > > > > Superblock backups stored on blocks: > > > > 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, > > > > 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, > > > > 102400000, 214990848 > > > > Allocating group tables: 0/7453 done > > > > Writing inode tables: 0/7453 done > > > > Creating journal (262144 blocks): [ 35.502102] BUG: kernel NULL > > > > pointer dereference, address: 000000c8 > > > > [ 35.508372] #PF: supervisor read access in kernel mode > > > > [ 35.513506] #PF: error_code(0x0000) - not-present page > > > > [ 35.518638] *pde = 00000000 > > > > [ 35.521514] Oops: 0000 [#1] SMP > > > > [ 35.524652] CPU: 0 PID: 145 Comm: kswapd0 Not tainted > > > > 5.7.0-rc6-next-20200519+ #1 > > > > [ 35.532121] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS > > > > 2.2 05/23/2018 > > > > [ 35.539507] EIP: mem_cgroup_get_nr_swap_pages+0x28/0x60 Swap accounting used to be implied-disabled when the cgroup controller was disabled. Restore that for the new cgroup_memory_noswap, so that we bail out of this function instead of dereferencing a NULL memcg. Link: http://lkml.kernel.org/r/20200521215855.GB815153@xxxxxxxxxxx Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Debugged-by: Hugh Dickins <hughd@xxxxxxxxxx> Debugged-by: Michal Hocko <mhocko@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/mm/memcontrol.c~mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control-fix-v2 +++ a/mm/memcontrol.c @@ -7152,7 +7152,11 @@ static struct cftype memsw_files[] = { static int __init mem_cgroup_swap_init(void) { - if (mem_cgroup_disabled() || cgroup_memory_noswap) + /* No memory control -> no swap control */ + if (mem_cgroup_disabled()) + cgroup_memory_noswap = true; + + if (cgroup_memory_noswap) return 0; WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); _ Patches currently in -mm which might be from hannes@xxxxxxxxxxx are mm-fix-numa-node-file-count-error-in-replace_page_cache.patch mm-memcontrol-fix-stat-corrupting-race-in-charge-moving.patch mm-memcontrol-drop-compound-parameter-from-memcg-charging-api.patch mm-shmem-remove-rare-optimization-when-swapin-races-with-hole-punching.patch mm-memcontrol-move-out-cgroup-swaprate-throttling.patch mm-memcontrol-convert-page-cache-to-a-new-mem_cgroup_charge-api.patch mm-memcontrol-prepare-uncharging-for-removal-of-private-page-type-counters.patch mm-memcontrol-prepare-move_account-for-removal-of-private-page-type-counters.patch mm-memcontrol-prepare-cgroup-vmstat-infrastructure-for-native-anon-counters.patch mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters.patch mm-memcontrol-switch-to-native-nr_anon_mapped-counter.patch mm-memcontrol-switch-to-native-nr_anon_thps-counter.patch mm-memcontrol-switch-to-native-nr_anon_thps-counter-fix.patch mm-memcontrol-convert-anon-and-file-thp-to-new-mem_cgroup_charge-api.patch mm-memcontrol-convert-anon-and-file-thp-to-new-mem_cgroup_charge-api-fix.patch mm-memcontrol-drop-unused-try-commit-cancel-charge-api.patch mm-memcontrol-prepare-swap-controller-setup-for-integration.patch mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control.patch mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control-fix-v2.patch mm-memcontrol-charge-swapin-pages-on-instantiation.patch mm-memcontrol-delete-unused-lrucare-handling.patch mm-memcontrol-update-page-mem_cgroup-stability-rules.patch mm-fix-lru-balancing-effect-of-new-transparent-huge-pages.patch mm-keep-separate-anon-and-file-statistics-on-page-reclaim-activity.patch mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset.patch mm-fold-and-remove-lru_cache_add_anon-and-lru_cache_add_file.patch mm-workingset-let-cache-workingset-challenge-anon.patch mm-remove-use-once-cache-bias-from-lru-balancing.patch mm-vmscan-drop-unnecessary-div0-avoidance-rounding-in-get_scan_count.patch mm-base-lru-balancing-on-an-explicit-cost-model.patch mm-deactivations-shouldnt-bias-the-lru-balance.patch mm-only-count-actual-rotations-as-lru-reclaim-cost.patch mm-balance-lru-lists-based-on-relative-thrashing.patch mm-vmscan-determine-anon-file-pressure-balance-at-the-reclaim-root.patch mm-vmscan-reclaim-writepage-is-io-cost.patch mm-vmscan-limit-the-range-of-lru-type-balancing.patch