Messages in this thread | | | Date | Wed, 8 May 2024 22:43:21 +0800 | From | Hailong Liu <> | Subject | Re: [RFC PATCH] mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL |
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On Wed, 08. May 21:41, Gao Xiang wrote: > > +Cc Michal, > > On 2024/5/8 20:58, hailong.liu@oppo.com wrote: > > From: "Hailong.Liu" <hailong.liu@oppo.com> > > > > 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@oppo.com> > > Signed-off-by: Hailong.Liu <hailong.liu@oppo.com> > > Why taging this as RFC here? It seems a corner-case fix of > commit a421ef303008 > > Thanks, > Gao Xiang >
Hi Gao Xiang:
RFC here to wait for a better way to handle this case :). IMO, if vmalloc support __GFP_NOFAIL it should not return null even system is deadlock on memory.
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Best Regards, Hailong.
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