On Wed, Mar 11, 2026 at 9:06 PM Li Wang <[email protected]> wrote: > > test_swapin_nozswap can hit OOM before reaching its assertions on some > setups. The test currently sets memory.max=8M and then allocates/reads > 32M with memory.zswap.max=0, which may over-constrain reclaim and kill > the workload process. > > Raise memory.max to 24M so the workload can make forward progress, and > lower the swap_peak expectation from 24M to 8M to keep the check robust > across environments. > > The test intent is unchanged: verify that swapping happens while zswap > remains unused when memory.zswap.max=0. > > === Error Logs === > > # ./test_zswap > TAP version 13 > 1..7 > ok 1 test_zswap_usage > not ok 2 test_swapin_nozswap > ... > > # dmesg > [271641.879153] test_zswap invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), > order=0, oom_score_adj=0 > [271641.879168] CPU: 1 UID: 0 PID: 177372 Comm: test_zswap Kdump: loaded > Not tainted 6.12.0-211.el10.ppc64le #1 VOLUNTARY > [271641.879171] Hardware name: IBM,9009-41A POWER9 (architected) 0x4e0202 > 0xf000005 of:IBM,FW940.02 (UL940_041) hv:phyp pSeries > [271641.879173] Call Trace: > [271641.879174] [c00000037540f730] [c00000000127ec44] > dump_stack_lvl+0x88/0xc4 (unreliable) > [271641.879184] [c00000037540f760] [c0000000005cc594] dump_header+0x5c/0x1e4 > [271641.879188] [c00000037540f7e0] [c0000000005cb464] > oom_kill_process+0x324/0x3b0 > [271641.879192] [c00000037540f860] [c0000000005cbe48] > out_of_memory+0x118/0x420 > [271641.879196] [c00000037540f8f0] [c00000000070d8ec] > mem_cgroup_out_of_memory+0x18c/0x1b0 > [271641.879200] [c00000037540f990] [c000000000713888] > try_charge_memcg+0x598/0x890 > [271641.879204] [c00000037540fa70] [c000000000713dbc] > charge_memcg+0x5c/0x110 > [271641.879207] [c00000037540faa0] [c0000000007159f8] > __mem_cgroup_charge+0x48/0x120 > [271641.879211] [c00000037540fae0] [c000000000641914] > alloc_anon_folio+0x2b4/0x5a0 > [271641.879215] [c00000037540fb60] [c000000000641d58] > do_anonymous_page+0x158/0x6b0 > [271641.879218] [c00000037540fbd0] [c000000000642f8c] > __handle_mm_fault+0x4bc/0x910 > [271641.879221] [c00000037540fcf0] [c000000000643500] > handle_mm_fault+0x120/0x3c0 > [271641.879224] [c00000037540fd40] [c00000000014bba0] > ___do_page_fault+0x1c0/0x980 > [271641.879228] [c00000037540fdf0] [c00000000014c44c] > hash__do_page_fault+0x2c/0xc0 > [271641.879232] [c00000037540fe20] [c0000000001565d8] > do_hash_fault+0x128/0x1d0 > [271641.879236] [c00000037540fe50] [c000000000008be0] > data_access_common_virt+0x210/0x220 > [271641.879548] Tasks state (memory values in pages): > ... > [271641.879550] [ pid ] uid tgid total_vm rss rss_anon rss_file > rss_shmem pgtables_bytes swapents oom_score_adj name > [271641.879555] [ 177372] 0 177372 571 0 0 0 > 0 51200 96 0 test_zswap > [271641.879562] > oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=/,mems_allowed=0,oom_memcg=/no_zswap_test,task_memcg=/no_zswap_test,task=test_zswap,pid=177372,uid=0 > [271641.879578] Memory cgroup out of memory: Killed process 177372 > (test_zswap) total-vm:36544kB, anon-rss:0kB, file-rss:0kB, shmem-rss:0kB, > UID:0 pgtables:50kB oom_score_adj:0 > > Signed-off-by: Li Wang <[email protected]> > Cc: Johannes Weiner <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Michal Koutný <[email protected]> > Cc: Muchun Song <[email protected]> > Cc: Nhat Pham <[email protected]> > Cc: Tejun Heo <[email protected]> > Cc: Roman Gushchin <[email protected]> > Cc: Shakeel Butt <[email protected]> > Cc: Yosry Ahmed <[email protected]>
Acked-by: Yosry Ahmed <[email protected]>
