From: "Kirill A. Shutemov" Subject: [PATCHv1, RFC 31/33] WIP: ext4: handle writeback with huge pages Date: Tue, 26 Jul 2016 03:35:33 +0300 Message-ID: <1469493335-3622-32-git-send-email-kirill.shutemov@linux.intel.com> References: <1469493335-3622-1-git-send-email-kirill.shutemov@linux.intel.com> Cc: Alexander Viro , Hugh Dickins , Andrea Arcangeli , Andrew Morton , Dave Hansen , Vlastimil Babka , Matthew Wilcox , Ross Zwisler , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, "Kirill A. Shutemov" To: "Theodore Ts'o" , Andreas Dilger , Jan Kara Return-path: In-Reply-To: <1469493335-3622-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org Modify mpage_map_and_submit_buffers() to do writeback with huge pages. This is somewhat unstable. I have hard time see full picture yet. More work is required. Not-yet-signed-off-by: Kirill A. Shutemov --- fs/ext4/inode.c | 40 ++++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 2e22f62f007b..29133e4550fc 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2088,16 +2088,16 @@ static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page) loff_t size = i_size_read(mpd->inode); int err; - BUG_ON(page->index != mpd->first_page); - if (page->index == size >> PAGE_SHIFT) - len = size & ~PAGE_MASK; - else - len = PAGE_SIZE; + page = compound_head(page); + len = hpage_size(page); + if (page->index + hpage_nr_pages(page) - 1 == size >> PAGE_SHIFT) + len = size & ~hpage_mask(page); + clear_page_dirty_for_io(page); err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false); if (!err) - mpd->wbc->nr_to_write--; - mpd->first_page++; + mpd->wbc->nr_to_write -= hpage_nr_pages(page); + mpd->first_page = round_up(mpd->first_page + 1, hpage_nr_pages(page)); return err; } @@ -2245,12 +2245,16 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) break; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; + unsigned long diff; - if (page->index > end) + if (page_to_pgoff(page) > end) break; /* Up to 'end' pages must be contiguous */ - BUG_ON(page->index != start); + BUG_ON(page_to_pgoff(page) != start); + diff = (page - compound_head(page)) << bpp_bits; bh = head = page_buffers(page); + while (diff--) + bh = bh->b_this_page; do { if (lblk < mpd->map.m_lblk) continue; @@ -2287,7 +2291,10 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) * supports blocksize < pagesize as we will try to * convert potentially unmapped parts of inode. */ - mpd->io_submit.io_end->size += PAGE_SIZE; + if (PageTransCompound(page)) + mpd->io_submit.io_end->size += HPAGE_PMD_SIZE; + else + mpd->io_submit.io_end->size += PAGE_SIZE; /* Page fully mapped - let IO run! */ err = mpage_submit_page(mpd, page); if (err < 0) { @@ -2295,6 +2302,10 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) return err; } start++; + if (PageTransCompound(page)) { + start = round_up(start, HPAGE_PMD_NR); + break; + } } pagevec_release(&pvec); } @@ -2534,7 +2545,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) * mapping. However, page->index will not change * because we have a reference on the page. */ - if (page->index > end) + if (page_to_pgoff(page) > end) goto out; /* @@ -2563,7 +2574,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) if (!PageDirty(page) || (PageWriteback(page) && (mpd->wbc->sync_mode == WB_SYNC_NONE)) || - unlikely(page->mapping != mapping)) { + unlikely(page_mapping(page) != mapping)) { unlock_page(page); continue; } @@ -2572,8 +2583,9 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) BUG_ON(PageWriteback(page)); if (mpd->map.m_len == 0) - mpd->first_page = page->index; - mpd->next_page = page->index + 1; + mpd->first_page = page_to_pgoff(page); + mpd->next_page = round_up(mpd->first_page + 1, + hpage_nr_pages(compound_head(page))); /* Add all dirty buffers to mpd */ lblk = ((ext4_lblk_t)page->index) << (PAGE_SHIFT - blkbits); -- 2.8.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org