On Wed, Mar 26, 2025 at 10:59 AM Matt Fleming <matt@xxxxxxxxxxxxxxxx> wrote: > > Hi there, > > I'm also seeing this PF_MEMALLOC WARN triggered from kswapd in 6.12.19. > > Does overlayfs need some kind of background inode reclaim support? Hey everyone, I know there was some off-list discussion last week at LSFMM, but I don't think a definite solution has been proposed for the below stacktrace. What is the shrinker API policy wrt memory allocation and I/O? Should overlayfs do something more like XFS and background reclaim to avoid GFP_NOFAIL allocations when kswapd is shrinking caches? > Call Trace: > <TASK> > __alloc_pages_noprof+0x31c/0x330 > alloc_pages_mpol_noprof+0xe3/0x1d0 > folio_alloc_noprof+0x5b/0xa0 > __filemap_get_folio+0x1f3/0x380 > __getblk_slow+0xa3/0x1e0 > __ext4_get_inode_loc+0x121/0x4b0 > ext4_get_inode_loc+0x40/0xa0 > ext4_reserve_inode_write+0x39/0xc0 > __ext4_mark_inode_dirty+0x5b/0x220 > ext4_evict_inode+0x26d/0x690 > evict+0x112/0x2a0 > __dentry_kill+0x71/0x180 > dput+0xeb/0x1b0 > ovl_stack_put+0x2e/0x50 [overlay] > ovl_destroy_inode+0x3a/0x60 [overlay] > destroy_inode+0x3b/0x70 > __dentry_kill+0x71/0x180 > shrink_dentry_list+0x6b/0xe0 > prune_dcache_sb+0x56/0x80 > super_cache_scan+0x12c/0x1e0 > do_shrink_slab+0x13b/0x350 > shrink_slab+0x278/0x3a0 > shrink_node+0x328/0x880 > balance_pgdat+0x36d/0x740 > kswapd+0x1f0/0x380 > kthread+0xd2/0x100 > ret_from_fork+0x34/0x50 > ret_from_fork_asm+0x1a/0x30 > </TASK>
