RE: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary slightly
Hi,
> -Original Message-
> From: Jaegeuk Kim [mailto:jaegeuk@samsung.com]
> Sent: Monday, March 10, 2014 1:38 PM
> To: Chao Yu
> Cc: 'Gu Zheng'; 'linux-kernel'; 'f2fs'
> Subject: RE: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary
> slightly
>
> Hi,
>
> 2014-03-10 (월), 13:13 +0800, Chao Yu:
> > Hi Gu, Kim:
> >
> > One more comment.
> >
> > > -Original Message-
> > > From: Jaegeuk Kim [mailto:jaegeuk@samsung.com]
> > > Sent: Monday, March 10, 2014 12:46 PM
> > > To: Gu Zheng
> > > Cc: linux-kernel; f2fs
> > > Subject: Re: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary
> > > slightly
> > >
> > > Hi Gu,
> > >
> > > 2014-03-07 (금), 18:43 +0800, Gu Zheng:
> > > > Previously, we ra_sum_pages to pre-read contiguous pages as more
> > > > as possible, and if we fail to alloc more pages, an ENOMEM error
> > > > will be reported upstream, even though we have alloced some pages
> > > > yet. In fact, we can use the available pages to do the job partly,
> > > > and continue the rest in the following circle. Only reporting ENOMEM
> > > > upstream if we really can not alloc any available page.
> > > >
> > > > And another fix is ignoring dealing with the following pages if an
> > > > EIO occurs when reading page from page_list.
> > > >
> > > > Signed-off-by: Gu Zheng
> >
> > Reviewed-by: Chao Yu
> >
> > > > ---
> > > > fs/f2fs/node.c| 44
> > > > fs/f2fs/segment.c |7 +--
> > > > 2 files changed, 25 insertions(+), 26 deletions(-)
> > > >
> > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > > index 8787469..4b7861d 100644
> > > > --- a/fs/f2fs/node.c
> > > > +++ b/fs/f2fs/node.c
> > > > @@ -1588,15 +1588,8 @@ static int ra_sum_pages(struct f2fs_sb_info
> > > > *sbi, struct list_head
> > > *pages,
> > > > for (; page_idx < start + nrpages; page_idx++) {
> > > > /* alloc temporal page for read node summary info*/
> > > > page = alloc_page(GFP_F2FS_ZERO);
> > > > - if (!page) {
> > > > - struct page *tmp;
> > > > - list_for_each_entry_safe(page, tmp, pages, lru)
> > > > {
> > > > - list_del(&page->lru);
> > > > - unlock_page(page);
> > > > - __free_pages(page, 0);
> > > > - }
> > > > - return -ENOMEM;
> > > > - }
> > > > + if (!page)
> > > > + break;
> > > >
> > > > lock_page(page);
> > > > page->index = page_idx;
> > > > @@ -1607,7 +1600,8 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi,
> > > > struct list_head
> > > *pages,
> > > > f2fs_submit_page_mbio(sbi, page, page->index, &fio);
> > > >
> > > > f2fs_submit_merged_bio(sbi, META, READ);
> > > > - return 0;
> > > > +
> > > > + return page_idx - start;
> > > > }
> > > >
> > > > int restore_node_summary(struct f2fs_sb_info *sbi,
> > > > @@ -1630,28 +1624,30 @@ int restore_node_summary(struct f2fs_sb_info
> > > > *sbi,
> > > > nrpages = min(last_offset - i, bio_blocks);
> > > >
> > > > /* read ahead node pages */
> > > > - err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > > - if (err)
> > > > - return err;
> > > > + nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > > + if (!nrpages)
> > > > + return -ENOMEM;
> > > >
> > > > list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > > > -
> > >
> > > Here we can just add:
> > > if (err)
> > > goto skip;
> > > lock_page();
> > > ...
> >
RE: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary slightly
Hi,
2014-03-10 (월), 13:13 +0800, Chao Yu:
> Hi Gu, Kim:
>
> One more comment.
>
> > -Original Message-
> > From: Jaegeuk Kim [mailto:jaegeuk@samsung.com]
> > Sent: Monday, March 10, 2014 12:46 PM
> > To: Gu Zheng
> > Cc: linux-kernel; f2fs
> > Subject: Re: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary
> > slightly
> >
> > Hi Gu,
> >
> > 2014-03-07 (금), 18:43 +0800, Gu Zheng:
> > > Previously, we ra_sum_pages to pre-read contiguous pages as more
> > > as possible, and if we fail to alloc more pages, an ENOMEM error
> > > will be reported upstream, even though we have alloced some pages
> > > yet. In fact, we can use the available pages to do the job partly,
> > > and continue the rest in the following circle. Only reporting ENOMEM
> > > upstream if we really can not alloc any available page.
> > >
> > > And another fix is ignoring dealing with the following pages if an
> > > EIO occurs when reading page from page_list.
> > >
> > > Signed-off-by: Gu Zheng
>
> Reviewed-by: Chao Yu
>
> > > ---
> > > fs/f2fs/node.c| 44
> > > fs/f2fs/segment.c |7 +--
> > > 2 files changed, 25 insertions(+), 26 deletions(-)
> > >
> > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > index 8787469..4b7861d 100644
> > > --- a/fs/f2fs/node.c
> > > +++ b/fs/f2fs/node.c
> > > @@ -1588,15 +1588,8 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi,
> > > struct list_head
> > *pages,
> > > for (; page_idx < start + nrpages; page_idx++) {
> > > /* alloc temporal page for read node summary info*/
> > > page = alloc_page(GFP_F2FS_ZERO);
> > > - if (!page) {
> > > - struct page *tmp;
> > > - list_for_each_entry_safe(page, tmp, pages, lru) {
> > > - list_del(&page->lru);
> > > - unlock_page(page);
> > > - __free_pages(page, 0);
> > > - }
> > > - return -ENOMEM;
> > > - }
> > > + if (!page)
> > > + break;
> > >
> > > lock_page(page);
> > > page->index = page_idx;
> > > @@ -1607,7 +1600,8 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi,
> > > struct list_head
> > *pages,
> > > f2fs_submit_page_mbio(sbi, page, page->index, &fio);
> > >
> > > f2fs_submit_merged_bio(sbi, META, READ);
> > > - return 0;
> > > +
> > > + return page_idx - start;
> > > }
> > >
> > > int restore_node_summary(struct f2fs_sb_info *sbi,
> > > @@ -1630,28 +1624,30 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
> > > nrpages = min(last_offset - i, bio_blocks);
> > >
> > > /* read ahead node pages */
> > > - err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > - if (err)
> > > - return err;
> > > + nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > + if (!nrpages)
> > > + return -ENOMEM;
> > >
> > > list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > > -
> >
> > Here we can just add:
> > if (err)
> > goto skip;
> > lock_page();
> > ...
> > unlock_page();
> > skip:
> > list_del();
> > __free_pages();
> >
> > IMO, it's more neat, so if you have any objection, let me know.
> > Otherwise, I'll handle this by myself. :)
> > Thanks,
> >
> > > - lock_page(page);
> > > - if (unlikely(!PageUptodate(page))) {
> > > - err = -EIO;
> > > - } else {
> > > - rn = F2FS_NODE(page);
> > > - sum_entry->nid = rn->footer.nid;
> > > - sum_entry->version = 0;
> > > - sum_entry->ofs_in_node = 0;
> > > - sum_entry++;
> > > + if (!err) {
>
> If we skip here, next round we will
RE: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary slightly
Hi Gu, Kim:
One more comment.
> -Original Message-
> From: Jaegeuk Kim [mailto:jaegeuk@samsung.com]
> Sent: Monday, March 10, 2014 12:46 PM
> To: Gu Zheng
> Cc: linux-kernel; f2fs
> Subject: Re: [f2fs-dev] [PATCH 4/5] f2fs: optimize restore_node_summary
> slightly
>
> Hi Gu,
>
> 2014-03-07 (금), 18:43 +0800, Gu Zheng:
> > Previously, we ra_sum_pages to pre-read contiguous pages as more
> > as possible, and if we fail to alloc more pages, an ENOMEM error
> > will be reported upstream, even though we have alloced some pages
> > yet. In fact, we can use the available pages to do the job partly,
> > and continue the rest in the following circle. Only reporting ENOMEM
> > upstream if we really can not alloc any available page.
> >
> > And another fix is ignoring dealing with the following pages if an
> > EIO occurs when reading page from page_list.
> >
> > Signed-off-by: Gu Zheng
Reviewed-by: Chao Yu
> > ---
> > fs/f2fs/node.c| 44
> > fs/f2fs/segment.c |7 +--
> > 2 files changed, 25 insertions(+), 26 deletions(-)
> >
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index 8787469..4b7861d 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1588,15 +1588,8 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi,
> > struct list_head
> *pages,
> > for (; page_idx < start + nrpages; page_idx++) {
> > /* alloc temporal page for read node summary info*/
> > page = alloc_page(GFP_F2FS_ZERO);
> > - if (!page) {
> > - struct page *tmp;
> > - list_for_each_entry_safe(page, tmp, pages, lru) {
> > - list_del(&page->lru);
> > - unlock_page(page);
> > - __free_pages(page, 0);
> > - }
> > - return -ENOMEM;
> > - }
> > + if (!page)
> > + break;
> >
> > lock_page(page);
> > page->index = page_idx;
> > @@ -1607,7 +1600,8 @@ static int ra_sum_pages(struct f2fs_sb_info *sbi,
> > struct list_head
> *pages,
> > f2fs_submit_page_mbio(sbi, page, page->index, &fio);
> >
> > f2fs_submit_merged_bio(sbi, META, READ);
> > - return 0;
> > +
> > + return page_idx - start;
> > }
> >
> > int restore_node_summary(struct f2fs_sb_info *sbi,
> > @@ -1630,28 +1624,30 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
> > nrpages = min(last_offset - i, bio_blocks);
> >
> > /* read ahead node pages */
> > - err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > - if (err)
> > - return err;
> > + nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > + if (!nrpages)
> > + return -ENOMEM;
> >
> > list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > -
>
> Here we can just add:
> if (err)
> goto skip;
> lock_page();
> ...
> unlock_page();
> skip:
> list_del();
> __free_pages();
>
> IMO, it's more neat, so if you have any objection, let me know.
> Otherwise, I'll handle this by myself. :)
> Thanks,
>
> > - lock_page(page);
> > - if (unlikely(!PageUptodate(page))) {
> > - err = -EIO;
> > - } else {
> > - rn = F2FS_NODE(page);
> > - sum_entry->nid = rn->footer.nid;
> > - sum_entry->version = 0;
> > - sum_entry->ofs_in_node = 0;
> > - sum_entry++;
> > + if (!err) {
If we skip here, next round we will fill these summary page entries with
wrong info because we skip the code 'sum_entry++;'.
> > + lock_page(page);
> > + if (unlikely(!PageUptodate(page))) {
> > + err = -EIO;
> > + } else {
> > + rn = F2FS_NODE(page);
> > + sum_entry->nid = rn->footer.nid;
> > +
