From 2d6c928241add2848e4eebfce407e95164229976 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 23 May 2016 16:25:42 -0700 Subject: [PATCH] mm: make vm_brk killable Now that all the callers handle vm_brk failure we can change it wait for mmap_sem killable to help oom_reaper to not get blocked just because vm_brk gets blocked behind mmap_sem readers. Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Cc: "Kirill A. Shutemov" Cc: Oleg Nesterov Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 2 +- mm/mmap.c | 9 +++------ 2 files changed, 4 insertions(+), 7 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index d5eb8dddd7c0..2835d598d258 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2011,7 +2011,7 @@ static inline void mm_populate(unsigned long addr, unsigned long len) {} #endif /* These take the mm semaphore themselves */ -extern unsigned long vm_brk(unsigned long, unsigned long); +extern unsigned long __must_check vm_brk(unsigned long, unsigned long); extern int vm_munmap(unsigned long, size_t); extern unsigned long __must_check vm_mmap(struct file *, unsigned long, unsigned long, unsigned long, diff --git a/mm/mmap.c b/mm/mmap.c index ca292a7c2b68..d3d9a94ca031 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2712,12 +2712,9 @@ unsigned long vm_brk(unsigned long addr, unsigned long len) unsigned long ret; bool populate; - /* - * XXX not all users are chcecking the return value, convert - * to down_write_killable after they are able to cope with - * error - */ - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; + ret = do_brk(addr, len); populate = ((mm->def_flags & VM_LOCKED) != 0); up_write(&mm->mmap_sem); -- 2.20.1