From: Hugh Dickins hughd@google.com Subject: mm: fix swap cache node allocation mask

https://bugzilla.kernel.org/show_bug.cgi?id=208085 reports that a slightly overcommitted load, testing swap and zram along with i915, splats and keeps on splatting, when it had better fail less noisily:

gnome-shell: page allocation failure: order:0, mode:0x400d0(__GFP_IO|__GFP_FS|__GFP_COMP|__GFP_RECLAIMABLE), nodemask=(null),cpuset=/,mems_allowed=0 CPU: 2 PID: 1155 Comm: gnome-shell Not tainted 5.7.0-1.fc33.x86_64 #1 Call Trace: dump_stack+0x64/0x88 warn_alloc.cold+0x75/0xd9 __alloc_pages_slowpath.constprop.0+0xcfa/0xd30 __alloc_pages_nodemask+0x2df/0x320 alloc_slab_page+0x195/0x310 allocate_slab+0x3c5/0x440 ___slab_alloc+0x40c/0x5f0 __slab_alloc+0x1c/0x30 kmem_cache_alloc+0x20e/0x220 xas_nomem+0x28/0x70 add_to_swap_cache+0x321/0x400 __read_swap_cache_async+0x105/0x240 swap_cluster_readahead+0x22c/0x2e0 shmem_swapin+0x8e/0xc0 shmem_swapin_page+0x196/0x740 shmem_getpage_gfp+0x3a2/0xa60 shmem_read_mapping_page_gfp+0x32/0x60 shmem_get_pages+0x155/0x5e0 [i915] __i915_gem_object_get_pages+0x68/0xa0 [i915] i915_vma_pin+0x3fe/0x6c0 [i915] eb_add_vma+0x10b/0x2c0 [i915] i915_gem_do_execbuffer+0x704/0x3430 [i915] i915_gem_execbuffer2_ioctl+0x1ea/0x3e0 [i915] drm_ioctl_kernel+0x86/0xd0 [drm] drm_ioctl+0x206/0x390 [drm] ksys_ioctl+0x82/0xc0 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x5b/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported on 5.7, but it goes back really to 3.1: when shmem_read_mapping_page_gfp() was implemented for use by i915, and allowed for __GFP_NORETRY and __GFP_NOWARN flags in most places, but missed swapin's "& GFP_KERNEL" mask for page tree node allocation in __read_swap_cache_async() - that was to mask off HIGHUSER_MOVABLE bits from what page cache uses, but GFP_RECLAIM_MASK is now what's needed.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2006151330070.11064@eggly.anvils Fixes: 68da9f055755 ("tmpfs: pass gfp to shmem_getpage_gfp") Signed-off-by: Hugh Dickins hughd@google.com Reviewed-by: Vlastimil Babka vbabka@suse.cz Reviewed-by: Matthew Wilcox (Oracle) willy@infradead.org Reported-by: Chris Murphy lists@colorremedies.com Analyzed-by: Vlastimil Babka vbabka@suse.cz Analyzed-by: Matthew Wilcox willy@infradead.org Tested-by: Chris Murphy lists@colorremedies.com Cc: stable@vger.kernel.org [3.1+] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/swap_state.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/swap_state.c~mm-fix-swap-cache-node-allocation-mask +++ a/mm/swap_state.c @@ -21,7 +21,7 @@ #include <linux/vmalloc.h> #include <linux/swap_slots.h> #include <linux/huge_mm.h> - +#include "internal.h"

/* * swapper_space is a fiction, retained to simplify the path through @@ -429,7 +429,7 @@ struct page *__read_swap_cache_async(swp __SetPageSwapBacked(page);

/* May fail (-ENOMEM) if XArray node allocation failed. */ - if (add_to_swap_cache(page, entry, gfp_mask & GFP_KERNEL)) { + if (add_to_swap_cache(page, entry, gfp_mask & GFP_RECLAIM_MASK)) { put_swap_page(page, entry); goto fail_unlock; } _