diff options
| author | Minchan Kim <minchan@kernel.org> | 2018-01-18 16:33:50 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-01-19 10:09:40 -0800 |
| commit | f80207727aaca3aa34a9cd80659393534de69cad (patch) | |
| tree | d9dc20d2ea690f091761bf6f5eed8d474f1f4857 | |
| parent | dda3e15231b35840fe6f0973f803cc70ddb86281 (diff) | |
mm/memory.c: release locked page in do_swap_page()
James reported a bug in swap paging-in from his testing. It is that
do_swap_page doesn't release locked page so system hang-up happens due
to a deadlock on PG_locked.
It was introduced by 0bcac06f27d7 ("mm, swap: skip swapcache for swapin
of synchronous device") because I missed swap cache hit places to update
swapcache variable to work well with other logics against swapcache in
do_swap_page.
This patch fixes it.
Debugged by James Bottomley.
Link: http://lkml.kernel.org/r/<1514407817.4169.4.camel@HansenPartnership.com>
Link: http://lkml.kernel.org/r/20180102235606.GA19438@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memory.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index ca5674cbaff2..793004608332 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2857,8 +2857,11 @@ int do_swap_page(struct vm_fault *vmf) int ret = 0; bool vma_readahead = swap_use_vma_readahead(); - if (vma_readahead) + if (vma_readahead) { page = swap_readahead_detect(vmf, &swap_ra); + swapcache = page; + } + if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte)) { if (page) put_page(page); @@ -2889,9 +2892,12 @@ int do_swap_page(struct vm_fault *vmf) delayacct_set_flag(DELAYACCT_PF_SWAPIN); - if (!page) + if (!page) { page = lookup_swap_cache(entry, vma_readahead ? vma : NULL, vmf->address); + swapcache = page; + } + if (!page) { struct swap_info_struct *si = swp_swap_info(entry); |