| Message ID | 20170703230820.63929-1-jaegeuk@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Jaegeuk, On 2017/7/4 7:08, Jaegeuk Kim wrote: > In order to avoid lock contention for atomic written pages, we'd better give > EAGAIN in f2fs_migrate_page. We expect it will be released soon as transaction > commits. Hmm.. if atomic write is triggered intensively, there is little change to migrate fragmented page. How about detecting migrate mode here, for MIGRATE_SYNC case, let it moving the page; for MIGRATE_ASYNC/MIGRATE_SYNC_LIGHT case, the migration priority is lower, we can return EAGAIN. Thanks, > > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > --- > fs/f2fs/data.c | 35 ++++++++++------------------------- > 1 file changed, 10 insertions(+), 25 deletions(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index d58b81213a86..1458e3a6d630 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2197,41 +2197,26 @@ static sector_t f2fs_bmap(struct address_space *mapping, sector_t block) > int f2fs_migrate_page(struct address_space *mapping, > struct page *newpage, struct page *page, enum migrate_mode mode) > { > - int rc, extra_count; > - struct f2fs_inode_info *fi = F2FS_I(mapping->host); > - bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page); > + int rc; > > - BUG_ON(PageWriteback(page)); > - > - /* migrating an atomic written page is safe with the inmem_lock hold */ > - if (atomic_written && !mutex_trylock(&fi->inmem_lock)) > + /* > + * We'd better return EAGAIN for atomic pages, which will be committed > + * sooner or later. Don't botter transactions with inmem_lock. > + */ > + if (IS_ATOMIC_WRITTEN_PAGE(page)) > return -EAGAIN; > > + BUG_ON(PageWriteback(page)); /* Writeback must be complete */ > + > /* > * A reference is expected if PagePrivate set when move mapping, > * however F2FS breaks this for maintaining dirty page counts when > * truncating pages. So here adjusting the 'extra_count' make it work. > */ > - extra_count = (atomic_written ? 1 : 0) - page_has_private(page); > rc = migrate_page_move_mapping(mapping, newpage, > - page, NULL, mode, extra_count); > - if (rc != MIGRATEPAGE_SUCCESS) { > - if (atomic_written) > - mutex_unlock(&fi->inmem_lock); > + page, NULL, mode, (page_has_private(page) ? -1 : 0)); > + if (rc != MIGRATEPAGE_SUCCESS) > return rc; > - } > - > - if (atomic_written) { > - struct inmem_pages *cur; > - list_for_each_entry(cur, &fi->inmem_pages, list) > - if (cur->page == page) { > - cur->page = newpage; > - break; > - } > - mutex_unlock(&fi->inmem_lock); > - put_page(page); > - get_page(newpage); > - } > > if (PagePrivate(page)) > SetPagePrivate(newpage); >
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index d58b81213a86..1458e3a6d630 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2197,41 +2197,26 @@ static sector_t f2fs_bmap(struct address_space *mapping, sector_t block) int f2fs_migrate_page(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode) { - int rc, extra_count; - struct f2fs_inode_info *fi = F2FS_I(mapping->host); - bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page); + int rc; - BUG_ON(PageWriteback(page)); - - /* migrating an atomic written page is safe with the inmem_lock hold */ - if (atomic_written && !mutex_trylock(&fi->inmem_lock)) + /* + * We'd better return EAGAIN for atomic pages, which will be committed + * sooner or later. Don't botter transactions with inmem_lock. + */ + if (IS_ATOMIC_WRITTEN_PAGE(page)) return -EAGAIN; + BUG_ON(PageWriteback(page)); /* Writeback must be complete */ + /* * A reference is expected if PagePrivate set when move mapping, * however F2FS breaks this for maintaining dirty page counts when * truncating pages. So here adjusting the 'extra_count' make it work. */ - extra_count = (atomic_written ? 1 : 0) - page_has_private(page); rc = migrate_page_move_mapping(mapping, newpage, - page, NULL, mode, extra_count); - if (rc != MIGRATEPAGE_SUCCESS) { - if (atomic_written) - mutex_unlock(&fi->inmem_lock); + page, NULL, mode, (page_has_private(page) ? -1 : 0)); + if (rc != MIGRATEPAGE_SUCCESS) return rc; - } - - if (atomic_written) { - struct inmem_pages *cur; - list_for_each_entry(cur, &fi->inmem_pages, list) - if (cur->page == page) { - cur->page = newpage; - break; - } - mutex_unlock(&fi->inmem_lock); - put_page(page); - get_page(newpage); - } if (PagePrivate(page)) SetPagePrivate(newpage);
In order to avoid lock contention for atomic written pages, we'd better give EAGAIN in f2fs_migrate_page. We expect it will be released soon as transaction commits. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> --- fs/f2fs/data.c | 35 ++++++++++------------------------- 1 file changed, 10 insertions(+), 25 deletions(-)