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References: <20221017202451.4951-1-vishal.moola@gmail.com> <20221017202451.4951-15-vishal.moola@gmail.com>
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In-Reply-To: <9c01bb74-97b3-d1c0-6a5f-dc8b11113e1a@kernel.org>
From:   Vishal Moola <vishal.moola@gmail.com>
Date:   Mon, 14 Nov 2022 13:38:56 -0800
Message-ID: <CAOzc2pweRFtsUj65=U-N-+ASf3cQybwMuABoVB+ciHzD1gKWhQ@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH v3 14/23] f2fs: Convert f2fs_write_cache_pages()
 to use filemap_get_folios_tag()
To:     Chao Yu <chao@kernel.org>
Cc:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org,
        fengnan chang <fengnanchang@gmail.com>,
        linux-fsdevel@vger.kernel.org
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On Sun, Nov 13, 2022 at 11:02 PM Chao Yu <chao@kernel.org> wrote:
>
> On 2022/10/18 4:24, Vishal Moola (Oracle) wrote:
> > Converted the function to use a folio_batch instead of pagevec. This is in
> > preparation for the removal of find_get_pages_range_tag().
> >
> > Also modified f2fs_all_cluster_page_ready to take in a folio_batch instead
> > of pagevec. This does NOT support large folios. The function currently
>
> Vishal,
>
> It looks this patch tries to revert Fengnan's change:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=01fc4b9a6ed8eacb64e5609bab7ac963e1c7e486
>
> How about doing some tests to evaluate its performance effect?

Yeah I'll play around with it to see how much of a difference it makes.

> +Cc Fengnan Chang
>
> Thanks,
>
> > only utilizes folios of size 1 so this shouldn't cause any issues right
> > now.
> >
> > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> > ---
> >   fs/f2fs/compress.c | 13 +++++----
> >   fs/f2fs/data.c     | 69 +++++++++++++++++++++++++---------------------
> >   fs/f2fs/f2fs.h     |  5 ++--
> >   3 files changed, 47 insertions(+), 40 deletions(-)
> >
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index d315c2de136f..7af6c923e0aa 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -842,10 +842,11 @@ bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index)
> >       return is_page_in_cluster(cc, index);
> >   }
> >
> > -bool f2fs_all_cluster_page_ready(struct compress_ctx *cc, struct page **pages,
> > -                             int index, int nr_pages, bool uptodate)
> > +bool f2fs_all_cluster_page_ready(struct compress_ctx *cc,
> > +                             struct folio_batch *fbatch,
> > +                             int index, int nr_folios, bool uptodate)
> >   {
> > -     unsigned long pgidx = pages[index]->index;
> > +     unsigned long pgidx = fbatch->folios[index]->index;
> >       int i = uptodate ? 0 : 1;
> >
> >       /*
> > @@ -855,13 +856,13 @@ bool f2fs_all_cluster_page_ready(struct compress_ctx *cc, struct page **pages,
> >       if (uptodate && (pgidx % cc->cluster_size))
> >               return false;
> >
> > -     if (nr_pages - index < cc->cluster_size)
> > +     if (nr_folios - index < cc->cluster_size)
> >               return false;
> >
> >       for (; i < cc->cluster_size; i++) {
> > -             if (pages[index + i]->index != pgidx + i)
> > +             if (fbatch->folios[index + i]->index != pgidx + i)
> >                       return false;
> > -             if (uptodate && !PageUptodate(pages[index + i]))
> > +             if (uptodate && !folio_test_uptodate(fbatch->folios[index + i]))
> >                       return false;
> >       }
> >
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index a71e818cd67b..7511578b73c3 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -2938,7 +2938,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >   {
> >       int ret = 0;
> >       int done = 0, retry = 0;
> > -     struct page *pages[F2FS_ONSTACK_PAGES];
> > +     struct folio_batch fbatch;
> >       struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
> >       struct bio *bio = NULL;
> >       sector_t last_block;
> > @@ -2959,7 +2959,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >               .private = NULL,
> >       };
> >   #endif
> > -     int nr_pages;
> > +     int nr_folios;
> >       pgoff_t index;
> >       pgoff_t end;            /* Inclusive */
> >       pgoff_t done_index;
> > @@ -2969,6 +2969,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >       int submitted = 0;
> >       int i;
> >
> > +     folio_batch_init(&fbatch);
> > +
> >       if (get_dirty_pages(mapping->host) <=
> >                               SM_I(F2FS_M_SB(mapping))->min_hot_blocks)
> >               set_inode_flag(mapping->host, FI_HOT_DATA);
> > @@ -2994,13 +2996,13 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >               tag_pages_for_writeback(mapping, index, end);
> >       done_index = index;
> >       while (!done && !retry && (index <= end)) {
> > -             nr_pages = find_get_pages_range_tag(mapping, &index, end,
> > -                             tag, F2FS_ONSTACK_PAGES, pages);
> > -             if (nr_pages == 0)
> > +             nr_folios = filemap_get_folios_tag(mapping, &index, end,
> > +                             tag, &fbatch);
> > +             if (nr_folios == 0)
> >                       break;
> >
> > -             for (i = 0; i < nr_pages; i++) {
> > -                     struct page *page = pages[i];
> > +             for (i = 0; i < nr_folios; i++) {
> > +                     struct folio *folio = fbatch.folios[i];
> >                       bool need_readd;
> >   readd:
> >                       need_readd = false;
> > @@ -3017,7 +3019,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >                               }
> >
> >                               if (!f2fs_cluster_can_merge_page(&cc,
> > -                                                             page->index)) {
> > +                                                             folio->index)) {
> >                                       ret = f2fs_write_multi_pages(&cc,
> >                                               &submitted, wbc, io_type);
> >                                       if (!ret)
> > @@ -3026,27 +3028,28 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >                               }
> >
> >                               if (unlikely(f2fs_cp_error(sbi)))
> > -                                     goto lock_page;
> > +                                     goto lock_folio;
> >
> >                               if (!f2fs_cluster_is_empty(&cc))
> > -                                     goto lock_page;
> > +                                     goto lock_folio;
> >
> >                               if (f2fs_all_cluster_page_ready(&cc,
> > -                                     pages, i, nr_pages, true))
> > -                                     goto lock_page;
> > +                                     &fbatch, i, nr_folios, true))
> > +                                     goto lock_folio;
> >
> >                               ret2 = f2fs_prepare_compress_overwrite(
> >                                                       inode, &pagep,
> > -                                                     page->index, &fsdata);
> > +                                                     folio->index, &fsdata);
> >                               if (ret2 < 0) {
> >                                       ret = ret2;
> >                                       done = 1;
> >                                       break;
> >                               } else if (ret2 &&
> >                                       (!f2fs_compress_write_end(inode,
> > -                                             fsdata, page->index, 1) ||
> > +                                             fsdata, folio->index, 1) ||
> >                                        !f2fs_all_cluster_page_ready(&cc,
> > -                                             pages, i, nr_pages, false))) {
> > +                                             &fbatch, i, nr_folios,
> > +                                             false))) {
> >                                       retry = 1;
> >                                       break;
> >                               }
> > @@ -3059,46 +3062,47 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >                               break;
> >                       }
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> > -lock_page:
> > +lock_folio:
> >   #endif
> > -                     done_index = page->index;
> > +                     done_index = folio->index;
> >   retry_write:
> > -                     lock_page(page);
> > +                     folio_lock(folio);
> >
> > -                     if (unlikely(page->mapping != mapping)) {
> > +                     if (unlikely(folio->mapping != mapping)) {
> >   continue_unlock:
> > -                             unlock_page(page);
> > +                             folio_unlock(folio);
> >                               continue;
> >                       }
> >
> > -                     if (!PageDirty(page)) {
> > +                     if (!folio_test_dirty(folio)) {
> >                               /* someone wrote it for us */
> >                               goto continue_unlock;
> >                       }
> >
> > -                     if (PageWriteback(page)) {
> > +                     if (folio_test_writeback(folio)) {
> >                               if (wbc->sync_mode != WB_SYNC_NONE)
> > -                                     f2fs_wait_on_page_writeback(page,
> > +                                     f2fs_wait_on_page_writeback(
> > +                                                     &folio->page,
> >                                                       DATA, true, true);
> >                               else
> >                                       goto continue_unlock;
> >                       }
> >
> > -                     if (!clear_page_dirty_for_io(page))
> > +                     if (!folio_clear_dirty_for_io(folio))
> >                               goto continue_unlock;
> >
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> >                       if (f2fs_compressed_file(inode)) {
> > -                             get_page(page);
> > -                             f2fs_compress_ctx_add_page(&cc, page);
> > +                             folio_get(folio);
> > +                             f2fs_compress_ctx_add_page(&cc, &folio->page);
> >                               continue;
> >                       }
> >   #endif
> > -                     ret = f2fs_write_single_data_page(page, &submitted,
> > -                                     &bio, &last_block, wbc, io_type,
> > -                                     0, true);
> > +                     ret = f2fs_write_single_data_page(&folio->page,
> > +                                     &submitted, &bio, &last_block,
> > +                                     wbc, io_type, 0, true);
> >                       if (ret == AOP_WRITEPAGE_ACTIVATE)
> > -                             unlock_page(page);
> > +                             folio_unlock(folio);
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> >   result:
> >   #endif
> > @@ -3122,7 +3126,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >                                       }
> >                                       goto next;
> >                               }
> > -                             done_index = page->index + 1;
> > +                             done_index = folio->index +
> > +                                     folio_nr_pages(folio);
> >                               done = 1;
> >                               break;
> >                       }
> > @@ -3136,7 +3141,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> >                       if (need_readd)
> >                               goto readd;
> >               }
> > -             release_pages(pages, nr_pages);
> > +             folio_batch_release(&fbatch);
> >               cond_resched();
> >       }
> >   #ifdef CONFIG_F2FS_FS_COMPRESSION
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index e6355a5683b7..d7bfb88fa341 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -4226,8 +4226,9 @@ void f2fs_end_read_compressed_page(struct page *page, bool failed,
> >                               block_t blkaddr, bool in_task);
> >   bool f2fs_cluster_is_empty(struct compress_ctx *cc);
> >   bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index);
> > -bool f2fs_all_cluster_page_ready(struct compress_ctx *cc, struct page **pages,
> > -                             int index, int nr_pages, bool uptodate);
> > +bool f2fs_all_cluster_page_ready(struct compress_ctx *cc,
> > +             struct folio_batch *fbatch, int index, int nr_folios,
> > +             bool uptodate);
> >   bool f2fs_sanity_check_cluster(struct dnode_of_data *dn);
> >   void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page);
> >   int f2fs_write_multi_pages(struct compress_ctx *cc,