From: Davidlohr Bueso <d...@stgolabs.net> Similarly to the anon memory counterpart, we can share the mapping's lock ownership as the interval tree is not modified when doing doing the walk, only the file page.
Signed-off-by: Davidlohr Bueso <dbu...@suse.de> Acked-by: Rik van Riel <r...@redhat.com> Acked-by: "Kirill A. Shutemov" <kir...@shutemov.name> Acked-by: Hugh Dickins <hu...@google.com> Cc: Oleg Nesterov <o...@redhat.com> Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Srikar Dronamraju <sri...@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgor...@suse.de> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> https://jira.sw.ru/browse/PSBM-122663 (cherry picked from commit 3dec0ba0be6a532cac949e02b853021bf6d57dad) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- include/linux/fs.h | 10 ++++++++++ mm/rmap.c | 9 +++++---- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index f422b0f7b02a..acedffc46fe4 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -709,6 +709,16 @@ static inline void i_mmap_unlock_write(struct address_space *mapping) up_write(&mapping->i_mmap_rwsem); } +static inline void i_mmap_lock_read(struct address_space *mapping) +{ + down_read(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_unlock_read(struct address_space *mapping) +{ + up_read(&mapping->i_mmap_rwsem); +} + /* * Might pages of this file be mapped into userspace? */ diff --git a/mm/rmap.c b/mm/rmap.c index e72be32c3dae..523957450d20 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1723,7 +1723,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) if (!mapping) return ret; pgoff = page_to_pgoff(page); - down_write_nested(&mapping->i_mmap_rwsem, SINGLE_DEPTH_NESTING); + + i_mmap_lock_read(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); @@ -1748,7 +1749,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) if (!mapping_mapped(peer)) continue; - i_mmap_lock_write(peer); + i_mmap_lock_read(peer); vma_interval_tree_foreach(vma, &peer->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); @@ -1764,7 +1765,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) cond_resched(); } - i_mmap_unlock_write(peer); + i_mmap_unlock_read(peer); if (ret != SWAP_AGAIN) goto done; @@ -1772,7 +1773,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) goto done; } done: - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); return ret; } -- 2.26.2 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
