On 2024/5/8 21:41, Gao Xiang wrote:
+Cc Michal,
On 2024/5/8 20:58, hailong.liu@xxxxxxxx wrote:
From: "Hailong.Liu" <hailong.liu@xxxxxxxx>
Commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc")
includes support for __GFP_NOFAIL, but it presents a conflict with
commit dd544141b9eb ("vmalloc: back off when the current task is
OOM-killed"). A possible scenario is as belows:
process-a
kvcalloc(n, m, GFP_KERNEL | __GFP_NOFAIL)
__vmalloc_node_range()
__vmalloc_area_node()
vm_area_alloc_pages()
--> oom-killer send SIGKILL to process-a
if (fatal_signal_pending(current)) break;
--> return NULL;
to fix this, do not check fatal_signal_pending() in vm_area_alloc_pages()
if __GFP_NOFAIL set.
Reported-by: Oven <liyangouwen1@xxxxxxxx>
Signed-off-by: Hailong.Liu <hailong.liu@xxxxxxxx>
Why taging this as RFC here? It seems a corner-case fix of
commit a421ef303008
BTW, I guess maybe commit e9c3cda4d86e ("mm, vmalloc: fix high order
__GFP_NOFAIL allocations") misses fatal_signal_pending() handling
anyway..
Thanks,
Gao Xiang
