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authorPeter Xu <peterx@redhat.com>2020-04-01 21:08:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-02 09:35:30 -0700
commit71335f37c5e8ec9225285206f7f875057b9737ad (patch)
tree7ee491f75201c017de56dc34885d7b9a4d72ecf4 /mm/gup.c
parent4426e945df588f2878affddf88a51259200f7e29 (diff)
mm/gup: allow to react to fatal signals
The existing gup code does not react to the fatal signals in many code paths. For example, in one retry path of gup we're still using down_read() rather than down_read_killable(). Also, when doing page faults we don't pass in FAULT_FLAG_KILLABLE as well, which means that within the faulting process we'll wait in non-killable way as well. These were spotted by Linus during the code review of some other patches. Let's allow the gup code to react to fatal signals to improve the responsiveness of threads when during gup and being killed. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Brian Geffon <bgeffon@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bobby Powers <bobbypowers@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Denis Plotnikov <dplotnikov@virtuozzo.com> Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Martin Cracauer <cracauer@cons.org> Cc: Marty McFadden <mcfadden8@llnl.gov> Cc: Matthew Wilcox <willy@infradead.org> Cc: Maya Gokhale <gokhale2@llnl.gov> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Link: http://lkml.kernel.org/r/20200220160256.9887-1-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/mm/gup.c b/mm/gup.c
index efe9038933d9..da3e03185144 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -864,7 +864,7 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma,
if (*flags & FOLL_REMOTE)
fault_flags |= FAULT_FLAG_REMOTE;
if (locked)
- fault_flags |= FAULT_FLAG_ALLOW_RETRY;
+ fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (*flags & FOLL_NOWAIT)
fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT;
if (*flags & FOLL_TRIED) {
@@ -1207,7 +1207,7 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
address = untagged_addr(address);
if (unlocked)
- fault_flags |= FAULT_FLAG_ALLOW_RETRY;
+ fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
retry:
vma = find_extend_vma(mm, address);
@@ -1329,7 +1329,13 @@ retry:
break;
*locked = 1;
- down_read(&mm->mmap_sem);
+ ret = down_read_killable(&mm->mmap_sem);
+ if (ret) {
+ BUG_ON(ret > 0);
+ if (!pages_done)
+ pages_done = ret;
+ break;
+ }
ret = __get_user_pages(tsk, mm, start, 1, flags | FOLL_TRIED,
pages, NULL, locked);