* [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
@ 2013-11-22 7:48 Chao Yu
2013-11-27 5:29 ` Jaegeuk Kim
0 siblings, 1 reply; 8+ messages in thread
From: Chao Yu @ 2013-11-22 7:48 UTC (permalink / raw)
To: ???; +Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel, 谭姝
If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
one by one, it makes low performance. So let's merge contiguous pages and
readahead for better performance.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
---
fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 63 insertions(+), 26 deletions(-)
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 4ac4150..81e704a 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
return 0;
}
+/*
+ * ra_sum_pages() merge contiguous pages into one bio and submit.
+ * these pre-readed pages are linked in pages list.
+ */
+static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
+ int start, int nrpages)
+{
+ struct page *page;
+ int page_idx = start;
+
+ for (; page_idx < start + nrpages; page_idx++) {
+ /* alloc temporal page for read node summary info*/
+ page = alloc_page(GFP_NOFS | __GFP_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;
+ }
+
+ lock_page(page);
+ page->index = page_idx;
+ list_add_tail(&page->lru, pages);
+ }
+
+ list_for_each_entry(page, pages, lru)
+ submit_read_page(sbi, page, page->index, READ_SYNC);
+
+ f2fs_submit_read_bio(sbi, READ_SYNC);
+ return 0;
+}
+
int restore_node_summary(struct f2fs_sb_info *sbi,
unsigned int segno, struct f2fs_summary_block *sum)
{
struct f2fs_node *rn;
struct f2fs_summary *sum_entry;
- struct page *page;
+ struct page *page, *tmp;
block_t addr;
- int i, last_offset;
-
- /* alloc temporal page for read node */
- page = alloc_page(GFP_NOFS | __GFP_ZERO);
- if (!page)
- return -ENOMEM;
- lock_page(page);
+ int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
+ int i, last_offset, nrpages, err = 0;
+ LIST_HEAD(page_list);
/* scan the node segment */
last_offset = sbi->blocks_per_seg;
addr = START_BLOCK(sbi, segno);
sum_entry = &sum->entries[0];
- for (i = 0; i < last_offset; i++, sum_entry++) {
- /*
- * In order to read next node page,
- * we must clear PageUptodate flag.
- */
- ClearPageUptodate(page);
+ for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
- if (f2fs_readpage(sbi, page, addr, READ_SYNC))
- goto out;
+ nrpages = min(last_offset - i, bio_blocks);
+ /* read ahead node pages */
+ err = ra_sum_pages(sbi, &page_list, addr, nrpages);
+ if (err)
+ return err;
- lock_page(page);
- rn = F2FS_NODE(page);
- sum_entry->nid = rn->footer.nid;
- sum_entry->version = 0;
- sum_entry->ofs_in_node = 0;
- addr++;
+ list_for_each_entry_safe(page, tmp, &page_list, lru) {
+
+ lock_page(page);
+ if(PageUptodate(page)) {
+ rn = F2FS_NODE(page);
+ sum_entry->nid = rn->footer.nid;
+ sum_entry->version = 0;
+ sum_entry->ofs_in_node = 0;
+ sum_entry++;
+ } else {
+ err = -EIO;
+ }
+
+ list_del(&page->lru);
+ unlock_page(page);
+ __free_pages(page, 0);
+ }
}
- unlock_page(page);
-out:
- __free_pages(page, 0);
- return 0;
+ return err;
}
static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
--
1.7.9.5
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-22 7:48 [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary Chao Yu
@ 2013-11-27 5:29 ` Jaegeuk Kim
2013-11-27 7:58 ` Chao Yu
0 siblings, 1 reply; 8+ messages in thread
From: Jaegeuk Kim @ 2013-11-27 5:29 UTC (permalink / raw)
To: Chao Yu; +Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel, 谭姝
Hi Chao,
It seems that we already have a readahed function for node pages,
ra_node_page().
So, we don't make a page list for this, but can use the node_inode's
page cache.
So how about writing ra_node_pages() which use the node_inode's page
cache?
Thanks,
2013-11-22 (금), 15:48 +0800, Chao Yu:
> If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
> one by one, it makes low performance. So let's merge contiguous pages and
> readahead for better performance.
>
> Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> ---
> fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
> 1 file changed, 63 insertions(+), 26 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 4ac4150..81e704a 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> return 0;
> }
>
> +/*
> + * ra_sum_pages() merge contiguous pages into one bio and submit.
> + * these pre-readed pages are linked in pages list.
> + */
> +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> + int start, int nrpages)
> +{
> + struct page *page;
> + int page_idx = start;
> +
> + for (; page_idx < start + nrpages; page_idx++) {
> + /* alloc temporal page for read node summary info*/
> + page = alloc_page(GFP_NOFS | __GFP_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;
> + }
> +
> + lock_page(page);
> + page->index = page_idx;
> + list_add_tail(&page->lru, pages);
> + }
> +
> + list_for_each_entry(page, pages, lru)
> + submit_read_page(sbi, page, page->index, READ_SYNC);
> +
> + f2fs_submit_read_bio(sbi, READ_SYNC);
> + return 0;
> +}
> +
> int restore_node_summary(struct f2fs_sb_info *sbi,
> unsigned int segno, struct f2fs_summary_block *sum)
> {
> struct f2fs_node *rn;
> struct f2fs_summary *sum_entry;
> - struct page *page;
> + struct page *page, *tmp;
> block_t addr;
> - int i, last_offset;
> -
> - /* alloc temporal page for read node */
> - page = alloc_page(GFP_NOFS | __GFP_ZERO);
> - if (!page)
> - return -ENOMEM;
> - lock_page(page);
> + int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> + int i, last_offset, nrpages, err = 0;
> + LIST_HEAD(page_list);
>
> /* scan the node segment */
> last_offset = sbi->blocks_per_seg;
> addr = START_BLOCK(sbi, segno);
> sum_entry = &sum->entries[0];
>
> - for (i = 0; i < last_offset; i++, sum_entry++) {
> - /*
> - * In order to read next node page,
> - * we must clear PageUptodate flag.
> - */
> - ClearPageUptodate(page);
> + for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
>
> - if (f2fs_readpage(sbi, page, addr, READ_SYNC))
> - goto out;
> + nrpages = min(last_offset - i, bio_blocks);
> + /* read ahead node pages */
> + err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> + if (err)
> + return err;
>
> - lock_page(page);
> - rn = F2FS_NODE(page);
> - sum_entry->nid = rn->footer.nid;
> - sum_entry->version = 0;
> - sum_entry->ofs_in_node = 0;
> - addr++;
> + list_for_each_entry_safe(page, tmp, &page_list, lru) {
> +
> + lock_page(page);
> + if(PageUptodate(page)) {
> + rn = F2FS_NODE(page);
> + sum_entry->nid = rn->footer.nid;
> + sum_entry->version = 0;
> + sum_entry->ofs_in_node = 0;
> + sum_entry++;
> + } else {
> + err = -EIO;
> + }
> +
> + list_del(&page->lru);
> + unlock_page(page);
> + __free_pages(page, 0);
> + }
> }
> - unlock_page(page);
> -out:
> - __free_pages(page, 0);
> - return 0;
> + return err;
> }
>
> static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
--
Jaegeuk Kim
Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-27 5:29 ` Jaegeuk Kim
@ 2013-11-27 7:58 ` Chao Yu
2013-11-27 8:19 ` Jaegeuk Kim
0 siblings, 1 reply; 8+ messages in thread
From: Chao Yu @ 2013-11-27 7:58 UTC (permalink / raw)
To: jaegeuk.kim
Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel,
'谭姝'
Hi Kim,
> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> Sent: Wednesday, November 27, 2013 1:30 PM
> To: Chao Yu
> Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; 谭姝
> Subject: Re: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
>
> Hi Chao,
>
> It seems that we already have a readahed function for node pages,
> ra_node_page().
> So, we don't make a page list for this, but can use the node_inode's
> page cache.
So you mean it's waste to release page list with updated data after we
finish work in restore_node_summary, right?
>
> So how about writing ra_node_pages() which use the node_inode's page
> cache?
Hmm, so ra_node_pages is introduced for read node_inode's pages which are
logical contiguously? and it also could take place of ra_node_page?
>
> Thanks,
>
> 2013-11-22 (금), 15:48 +0800, Chao Yu:
> > If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
> > one by one, it makes low performance. So let's merge contiguous pages and
> > readahead for better performance.
> >
> > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > ---
> > fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
> > 1 file changed, 63 insertions(+), 26 deletions(-)
> >
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index 4ac4150..81e704a 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> > return 0;
> > }
> >
> > +/*
> > + * ra_sum_pages() merge contiguous pages into one bio and submit.
> > + * these pre-readed pages are linked in pages list.
> > + */
> > +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> > + int start, int nrpages)
> > +{
> > + struct page *page;
> > + int page_idx = start;
> > +
> > + for (; page_idx < start + nrpages; page_idx++) {
> > + /* alloc temporal page for read node summary info*/
> > + page = alloc_page(GFP_NOFS | __GFP_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;
> > + }
> > +
> > + lock_page(page);
> > + page->index = page_idx;
> > + list_add_tail(&page->lru, pages);
> > + }
> > +
> > + list_for_each_entry(page, pages, lru)
> > + submit_read_page(sbi, page, page->index, READ_SYNC);
> > +
> > + f2fs_submit_read_bio(sbi, READ_SYNC);
> > + return 0;
> > +}
> > +
> > int restore_node_summary(struct f2fs_sb_info *sbi,
> > unsigned int segno, struct f2fs_summary_block *sum)
> > {
> > struct f2fs_node *rn;
> > struct f2fs_summary *sum_entry;
> > - struct page *page;
> > + struct page *page, *tmp;
> > block_t addr;
> > - int i, last_offset;
> > -
> > - /* alloc temporal page for read node */
> > - page = alloc_page(GFP_NOFS | __GFP_ZERO);
> > - if (!page)
> > - return -ENOMEM;
> > - lock_page(page);
> > + int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> > + int i, last_offset, nrpages, err = 0;
> > + LIST_HEAD(page_list);
> >
> > /* scan the node segment */
> > last_offset = sbi->blocks_per_seg;
> > addr = START_BLOCK(sbi, segno);
> > sum_entry = &sum->entries[0];
> >
> > - for (i = 0; i < last_offset; i++, sum_entry++) {
> > - /*
> > - * In order to read next node page,
> > - * we must clear PageUptodate flag.
> > - */
> > - ClearPageUptodate(page);
> > + for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
> >
> > - if (f2fs_readpage(sbi, page, addr, READ_SYNC))
> > - goto out;
> > + nrpages = min(last_offset - i, bio_blocks);
> > + /* read ahead node pages */
> > + err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > + if (err)
> > + return err;
> >
> > - lock_page(page);
> > - rn = F2FS_NODE(page);
> > - sum_entry->nid = rn->footer.nid;
> > - sum_entry->version = 0;
> > - sum_entry->ofs_in_node = 0;
> > - addr++;
> > + list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > +
> > + lock_page(page);
> > + if(PageUptodate(page)) {
> > + rn = F2FS_NODE(page);
> > + sum_entry->nid = rn->footer.nid;
> > + sum_entry->version = 0;
> > + sum_entry->ofs_in_node = 0;
> > + sum_entry++;
> > + } else {
> > + err = -EIO;
> > + }
> > +
> > + list_del(&page->lru);
> > + unlock_page(page);
> > + __free_pages(page, 0);
> > + }
> > }
> > - unlock_page(page);
> > -out:
> > - __free_pages(page, 0);
> > - return 0;
> > + return err;
> > }
> >
> > static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
>
> --
> Jaegeuk Kim
> Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-27 7:58 ` Chao Yu
@ 2013-11-27 8:19 ` Jaegeuk Kim
2013-11-28 1:26 ` Chao Yu
0 siblings, 1 reply; 8+ messages in thread
From: Jaegeuk Kim @ 2013-11-27 8:19 UTC (permalink / raw)
To: Chao Yu
Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel,
'谭姝'
Hi,
2013-11-27 (수), 15:58 +0800, Chao Yu:
> Hi Kim,
>
> > -----Original Message-----
> > From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> > Sent: Wednesday, November 27, 2013 1:30 PM
> > To: Chao Yu
> > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; 谭姝
> > Subject: Re: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
> >
> > Hi Chao,
> >
> > It seems that we already have a readahed function for node pages,
> > ra_node_page().
> > So, we don't make a page list for this, but can use the node_inode's
> > page cache.
>
> So you mean it's waste to release page list with updated data after we
> finish work in restore_node_summary, right?
Right.
>
> >
> > So how about writing ra_node_pages() which use the node_inode's page
> > cache?
>
> Hmm, so ra_node_pages is introduced for read node_inode's pages which are
> logical contiguously? and it also could take place of ra_node_page?
Ah. The ra_node_page() read a node page ahead for a given node id.
So it doesn't match exactly between ra_node_page() and ra_node_pages()
that I suggested.
So how about reading node pages and then caching some of them in the
page cache, node_inode's address space?
Thanks,
>
>
> >
> > Thanks,
> >
> > 2013-11-22 (금), 15:48 +0800, Chao Yu:
> > > If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
> > > one by one, it makes low performance. So let's merge contiguous pages and
> > > readahead for better performance.
> > >
> > > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > > ---
> > > fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
> > > 1 file changed, 63 insertions(+), 26 deletions(-)
> > >
> > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > index 4ac4150..81e704a 100644
> > > --- a/fs/f2fs/node.c
> > > +++ b/fs/f2fs/node.c
> > > @@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> > > return 0;
> > > }
> > >
> > > +/*
> > > + * ra_sum_pages() merge contiguous pages into one bio and submit.
> > > + * these pre-readed pages are linked in pages list.
> > > + */
> > > +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> > > + int start, int nrpages)
> > > +{
> > > + struct page *page;
> > > + int page_idx = start;
> > > +
> > > + for (; page_idx < start + nrpages; page_idx++) {
> > > + /* alloc temporal page for read node summary info*/
> > > + page = alloc_page(GFP_NOFS | __GFP_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;
> > > + }
> > > +
> > > + lock_page(page);
> > > + page->index = page_idx;
> > > + list_add_tail(&page->lru, pages);
> > > + }
> > > +
> > > + list_for_each_entry(page, pages, lru)
> > > + submit_read_page(sbi, page, page->index, READ_SYNC);
> > > +
> > > + f2fs_submit_read_bio(sbi, READ_SYNC);
> > > + return 0;
> > > +}
> > > +
> > > int restore_node_summary(struct f2fs_sb_info *sbi,
> > > unsigned int segno, struct f2fs_summary_block *sum)
> > > {
> > > struct f2fs_node *rn;
> > > struct f2fs_summary *sum_entry;
> > > - struct page *page;
> > > + struct page *page, *tmp;
> > > block_t addr;
> > > - int i, last_offset;
> > > -
> > > - /* alloc temporal page for read node */
> > > - page = alloc_page(GFP_NOFS | __GFP_ZERO);
> > > - if (!page)
> > > - return -ENOMEM;
> > > - lock_page(page);
> > > + int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> > > + int i, last_offset, nrpages, err = 0;
> > > + LIST_HEAD(page_list);
> > >
> > > /* scan the node segment */
> > > last_offset = sbi->blocks_per_seg;
> > > addr = START_BLOCK(sbi, segno);
> > > sum_entry = &sum->entries[0];
> > >
> > > - for (i = 0; i < last_offset; i++, sum_entry++) {
> > > - /*
> > > - * In order to read next node page,
> > > - * we must clear PageUptodate flag.
> > > - */
> > > - ClearPageUptodate(page);
> > > + for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
> > >
> > > - if (f2fs_readpage(sbi, page, addr, READ_SYNC))
> > > - goto out;
> > > + nrpages = min(last_offset - i, bio_blocks);
> > > + /* read ahead node pages */
> > > + err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > + if (err)
> > > + return err;
> > >
> > > - lock_page(page);
> > > - rn = F2FS_NODE(page);
> > > - sum_entry->nid = rn->footer.nid;
> > > - sum_entry->version = 0;
> > > - sum_entry->ofs_in_node = 0;
> > > - addr++;
> > > + list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > > +
> > > + lock_page(page);
> > > + if(PageUptodate(page)) {
> > > + rn = F2FS_NODE(page);
> > > + sum_entry->nid = rn->footer.nid;
> > > + sum_entry->version = 0;
> > > + sum_entry->ofs_in_node = 0;
> > > + sum_entry++;
> > > + } else {
> > > + err = -EIO;
> > > + }
> > > +
> > > + list_del(&page->lru);
> > > + unlock_page(page);
> > > + __free_pages(page, 0);
> > > + }
> > > }
> > > - unlock_page(page);
> > > -out:
> > > - __free_pages(page, 0);
> > > - return 0;
> > > + return err;
> > > }
> > >
> > > static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
> >
> > --
> > Jaegeuk Kim
> > Samsung
>
--
Jaegeuk Kim
Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-27 8:19 ` Jaegeuk Kim
@ 2013-11-28 1:26 ` Chao Yu
2013-11-28 3:33 ` Jaegeuk Kim
0 siblings, 1 reply; 8+ messages in thread
From: Chao Yu @ 2013-11-28 1:26 UTC (permalink / raw)
To: jaegeuk.kim
Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel,
'谭姝'
Hi Kim,
> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> Sent: Wednesday, November 27, 2013 4:19 PM
> To: Chao Yu
> Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; '谭姝'
> Subject: RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
>
> Hi,
>
> 2013-11-27 (수), 15:58 +0800, Chao Yu:
> > Hi Kim,
> >
> > > -----Original Message-----
> > > From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> > > Sent: Wednesday, November 27, 2013 1:30 PM
> > > To: Chao Yu
> > > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; 谭姝
> > > Subject: Re: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
> > >
> > > Hi Chao,
> > >
> > > It seems that we already have a readahed function for node pages,
> > > ra_node_page().
> > > So, we don't make a page list for this, but can use the node_inode's
> > > page cache.
> >
> > So you mean it's waste to release page list with updated data after we
> > finish work in restore_node_summary, right?
>
> Right.
So how about add all pages of page list to node_inode's address space by
add_to_page_cache_lru() with arg sum_entry->nid?
>
> >
> > >
> > > So how about writing ra_node_pages() which use the node_inode's page
> > > cache?
> >
> > Hmm, so ra_node_pages is introduced for read node_inode's pages which are
> > logical contiguously? and it also could take place of ra_node_page?
>
> Ah. The ra_node_page() read a node page ahead for a given node id.
> So it doesn't match exactly between ra_node_page() and ra_node_pages()
> that I suggested.
> So how about reading node pages and then caching some of them in the
> page cache, node_inode's address space?
Got it,
If we do not use the method above, we should search the NAT for nid number
as the index of node_inode's page by the specified node page blkaddr, that costs
a lot.
How do you think?
>
> Thanks,
>
> >
> >
> > >
> > > Thanks,
> > >
> > > 2013-11-22 (금), 15:48 +0800, Chao Yu:
> > > > If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
> > > > one by one, it makes low performance. So let's merge contiguous pages and
> > > > readahead for better performance.
> > > >
> > > > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > > > ---
> > > > fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
> > > > 1 file changed, 63 insertions(+), 26 deletions(-)
> > > >
> > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > > index 4ac4150..81e704a 100644
> > > > --- a/fs/f2fs/node.c
> > > > +++ b/fs/f2fs/node.c
> > > > @@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> > > > return 0;
> > > > }
> > > >
> > > > +/*
> > > > + * ra_sum_pages() merge contiguous pages into one bio and submit.
> > > > + * these pre-readed pages are linked in pages list.
> > > > + */
> > > > +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> > > > + int start, int nrpages)
> > > > +{
> > > > + struct page *page;
> > > > + int page_idx = start;
> > > > +
> > > > + for (; page_idx < start + nrpages; page_idx++) {
> > > > + /* alloc temporal page for read node summary info*/
> > > > + page = alloc_page(GFP_NOFS | __GFP_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;
> > > > + }
> > > > +
> > > > + lock_page(page);
> > > > + page->index = page_idx;
> > > > + list_add_tail(&page->lru, pages);
> > > > + }
> > > > +
> > > > + list_for_each_entry(page, pages, lru)
> > > > + submit_read_page(sbi, page, page->index, READ_SYNC);
> > > > +
> > > > + f2fs_submit_read_bio(sbi, READ_SYNC);
> > > > + return 0;
> > > > +}
> > > > +
> > > > int restore_node_summary(struct f2fs_sb_info *sbi,
> > > > unsigned int segno, struct f2fs_summary_block *sum)
> > > > {
> > > > struct f2fs_node *rn;
> > > > struct f2fs_summary *sum_entry;
> > > > - struct page *page;
> > > > + struct page *page, *tmp;
> > > > block_t addr;
> > > > - int i, last_offset;
> > > > -
> > > > - /* alloc temporal page for read node */
> > > > - page = alloc_page(GFP_NOFS | __GFP_ZERO);
> > > > - if (!page)
> > > > - return -ENOMEM;
> > > > - lock_page(page);
> > > > + int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> > > > + int i, last_offset, nrpages, err = 0;
> > > > + LIST_HEAD(page_list);
> > > >
> > > > /* scan the node segment */
> > > > last_offset = sbi->blocks_per_seg;
> > > > addr = START_BLOCK(sbi, segno);
> > > > sum_entry = &sum->entries[0];
> > > >
> > > > - for (i = 0; i < last_offset; i++, sum_entry++) {
> > > > - /*
> > > > - * In order to read next node page,
> > > > - * we must clear PageUptodate flag.
> > > > - */
> > > > - ClearPageUptodate(page);
> > > > + for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
> > > >
> > > > - if (f2fs_readpage(sbi, page, addr, READ_SYNC))
> > > > - goto out;
> > > > + nrpages = min(last_offset - i, bio_blocks);
> > > > + /* read ahead node pages */
> > > > + err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > > + if (err)
> > > > + return err;
> > > >
> > > > - lock_page(page);
> > > > - rn = F2FS_NODE(page);
> > > > - sum_entry->nid = rn->footer.nid;
> > > > - sum_entry->version = 0;
> > > > - sum_entry->ofs_in_node = 0;
> > > > - addr++;
> > > > + list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > > > +
> > > > + lock_page(page);
> > > > + if(PageUptodate(page)) {
> > > > + rn = F2FS_NODE(page);
> > > > + sum_entry->nid = rn->footer.nid;
> > > > + sum_entry->version = 0;
> > > > + sum_entry->ofs_in_node = 0;
> > > > + sum_entry++;
> > > > + } else {
> > > > + err = -EIO;
> > > > + }
> > > > +
> > > > + list_del(&page->lru);
> > > > + unlock_page(page);
> > > > + __free_pages(page, 0);
> > > > + }
> > > > }
> > > > - unlock_page(page);
> > > > -out:
> > > > - __free_pages(page, 0);
> > > > - return 0;
> > > > + return err;
> > > > }
> > > >
> > > > static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
> > >
> > > --
> > > Jaegeuk Kim
> > > Samsung
> >
>
> --
> Jaegeuk Kim
> Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-28 1:26 ` Chao Yu
@ 2013-11-28 3:33 ` Jaegeuk Kim
2013-11-28 5:56 ` Chao Yu
0 siblings, 1 reply; 8+ messages in thread
From: Jaegeuk Kim @ 2013-11-28 3:33 UTC (permalink / raw)
To: Chao Yu
Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel,
'谭姝'
Hi,
2013-11-28 (목), 09:26 +0800, Chao Yu:
> Hi Kim,
>
> > -----Original Message-----
> > From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> > Sent: Wednesday, November 27, 2013 4:19 PM
> > To: Chao Yu
> > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; '谭姝'
> > Subject: RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
> >
> > Hi,
> >
> > 2013-11-27 (수), 15:58 +0800, Chao Yu:
> > > Hi Kim,
> > >
> > > > -----Original Message-----
> > > > From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> > > > Sent: Wednesday, November 27, 2013 1:30 PM
> > > > To: Chao Yu
> > > > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; 谭姝
> > > > Subject: Re: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
> > > >
> > > > Hi Chao,
> > > >
> > > > It seems that we already have a readahed function for node pages,
> > > > ra_node_page().
> > > > So, we don't make a page list for this, but can use the node_inode's
> > > > page cache.
> > >
> > > So you mean it's waste to release page list with updated data after we
> > > finish work in restore_node_summary, right?
> >
> > Right.
>
> So how about add all pages of page list to node_inode's address space by
> add_to_page_cache_lru() with arg sum_entry->nid?
I don't think it's proper way to use add_to_page_cache_lru() directly.
>
> >
> > >
> > > >
> > > > So how about writing ra_node_pages() which use the node_inode's page
> > > > cache?
> > >
> > > Hmm, so ra_node_pages is introduced for read node_inode's pages which are
> > > logical contiguously? and it also could take place of ra_node_page?
> >
> > Ah. The ra_node_page() read a node page ahead for a given node id.
> > So it doesn't match exactly between ra_node_page() and ra_node_pages()
> > that I suggested.
> > So how about reading node pages and then caching some of them in the
> > page cache, node_inode's address space?
>
> Got it,
> If we do not use the method above, we should search the NAT for nid number
> as the index of node_inode's page by the specified node page blkaddr, that costs
> a lot.
> How do you think?
1. grab_cache_page(node_footer->nid);
2. memcpy();
3. SetPageUptodate();
4. f2fs_put_page();
Thanks,
>
> >
> > Thanks,
> >
> > >
> > >
> > > >
> > > > Thanks,
> > > >
> > > > 2013-11-22 (금), 15:48 +0800, Chao Yu:
> > > > > If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
> > > > > one by one, it makes low performance. So let's merge contiguous pages and
> > > > > readahead for better performance.
> > > > >
> > > > > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > > > > ---
> > > > > fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
> > > > > 1 file changed, 63 insertions(+), 26 deletions(-)
> > > > >
> > > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > > > index 4ac4150..81e704a 100644
> > > > > --- a/fs/f2fs/node.c
> > > > > +++ b/fs/f2fs/node.c
> > > > > @@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> > > > > return 0;
> > > > > }
> > > > >
> > > > > +/*
> > > > > + * ra_sum_pages() merge contiguous pages into one bio and submit.
> > > > > + * these pre-readed pages are linked in pages list.
> > > > > + */
> > > > > +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> > > > > + int start, int nrpages)
> > > > > +{
> > > > > + struct page *page;
> > > > > + int page_idx = start;
> > > > > +
> > > > > + for (; page_idx < start + nrpages; page_idx++) {
> > > > > + /* alloc temporal page for read node summary info*/
> > > > > + page = alloc_page(GFP_NOFS | __GFP_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;
> > > > > + }
> > > > > +
> > > > > + lock_page(page);
> > > > > + page->index = page_idx;
> > > > > + list_add_tail(&page->lru, pages);
> > > > > + }
> > > > > +
> > > > > + list_for_each_entry(page, pages, lru)
> > > > > + submit_read_page(sbi, page, page->index, READ_SYNC);
> > > > > +
> > > > > + f2fs_submit_read_bio(sbi, READ_SYNC);
> > > > > + return 0;
> > > > > +}
> > > > > +
> > > > > int restore_node_summary(struct f2fs_sb_info *sbi,
> > > > > unsigned int segno, struct f2fs_summary_block *sum)
> > > > > {
> > > > > struct f2fs_node *rn;
> > > > > struct f2fs_summary *sum_entry;
> > > > > - struct page *page;
> > > > > + struct page *page, *tmp;
> > > > > block_t addr;
> > > > > - int i, last_offset;
> > > > > -
> > > > > - /* alloc temporal page for read node */
> > > > > - page = alloc_page(GFP_NOFS | __GFP_ZERO);
> > > > > - if (!page)
> > > > > - return -ENOMEM;
> > > > > - lock_page(page);
> > > > > + int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> > > > > + int i, last_offset, nrpages, err = 0;
> > > > > + LIST_HEAD(page_list);
> > > > >
> > > > > /* scan the node segment */
> > > > > last_offset = sbi->blocks_per_seg;
> > > > > addr = START_BLOCK(sbi, segno);
> > > > > sum_entry = &sum->entries[0];
> > > > >
> > > > > - for (i = 0; i < last_offset; i++, sum_entry++) {
> > > > > - /*
> > > > > - * In order to read next node page,
> > > > > - * we must clear PageUptodate flag.
> > > > > - */
> > > > > - ClearPageUptodate(page);
> > > > > + for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
> > > > >
> > > > > - if (f2fs_readpage(sbi, page, addr, READ_SYNC))
> > > > > - goto out;
> > > > > + nrpages = min(last_offset - i, bio_blocks);
> > > > > + /* read ahead node pages */
> > > > > + err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > > > + if (err)
> > > > > + return err;
> > > > >
> > > > > - lock_page(page);
> > > > > - rn = F2FS_NODE(page);
> > > > > - sum_entry->nid = rn->footer.nid;
> > > > > - sum_entry->version = 0;
> > > > > - sum_entry->ofs_in_node = 0;
> > > > > - addr++;
> > > > > + list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > > > > +
> > > > > + lock_page(page);
> > > > > + if(PageUptodate(page)) {
> > > > > + rn = F2FS_NODE(page);
> > > > > + sum_entry->nid = rn->footer.nid;
> > > > > + sum_entry->version = 0;
> > > > > + sum_entry->ofs_in_node = 0;
> > > > > + sum_entry++;
> > > > > + } else {
> > > > > + err = -EIO;
> > > > > + }
> > > > > +
> > > > > + list_del(&page->lru);
> > > > > + unlock_page(page);
> > > > > + __free_pages(page, 0);
> > > > > + }
> > > > > }
> > > > > - unlock_page(page);
> > > > > -out:
> > > > > - __free_pages(page, 0);
> > > > > - return 0;
> > > > > + return err;
> > > > > }
> > > > >
> > > > > static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
> > > >
> > > > --
> > > > Jaegeuk Kim
> > > > Samsung
> > >
> >
> > --
> > Jaegeuk Kim
> > Samsung
>
--
Jaegeuk Kim
Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-28 3:33 ` Jaegeuk Kim
@ 2013-11-28 5:56 ` Chao Yu
2013-11-30 5:12 ` Jaegeuk Kim
0 siblings, 1 reply; 8+ messages in thread
From: Chao Yu @ 2013-11-28 5:56 UTC (permalink / raw)
To: jaegeuk.kim
Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel,
'谭姝'
Hi,
> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> Sent: Thursday, November 28, 2013 11:33 AM
> To: Chao Yu
> Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; '谭姝'
> Subject: RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
>
> Hi,
>
> 2013-11-28 (목), 09:26 +0800, Chao Yu:
> > Hi Kim,
> >
> > > -----Original Message-----
> > > From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> > > Sent: Wednesday, November 27, 2013 4:19 PM
> > > To: Chao Yu
> > > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; '谭姝'
> > > Subject: RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
> > >
> > > Hi,
> > >
> > > 2013-11-27 (수), 15:58 +0800, Chao Yu:
> > > > Hi Kim,
> > > >
> > > > > -----Original Message-----
> > > > > From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> > > > > Sent: Wednesday, November 27, 2013 1:30 PM
> > > > > To: Chao Yu
> > > > > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; 谭姝
> > > > > Subject: Re: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
> > > > >
> > > > > Hi Chao,
> > > > >
> > > > > It seems that we already have a readahed function for node pages,
> > > > > ra_node_page().
> > > > > So, we don't make a page list for this, but can use the node_inode's
> > > > > page cache.
> > > >
> > > > So you mean it's waste to release page list with updated data after we
> > > > finish work in restore_node_summary, right?
> > >
> > > Right.
> >
> > So how about add all pages of page list to node_inode's address space by
> > add_to_page_cache_lru() with arg sum_entry->nid?
>
> I don't think it's proper way to use add_to_page_cache_lru() directly.
This is the way used in VM readahead(i.e. read_pages/mpage_readpages/
read_cache_pages).
So what you worry about is that using lonely add_to_page_cache_lru()
may cause exception, is it?
>
> >
> > >
> > > >
> > > > >
> > > > > So how about writing ra_node_pages() which use the node_inode's page
> > > > > cache?
> > > >
> > > > Hmm, so ra_node_pages is introduced for read node_inode's pages which are
> > > > logical contiguously? and it also could take place of ra_node_page?
> > >
> > > Ah. The ra_node_page() read a node page ahead for a given node id.
> > > So it doesn't match exactly between ra_node_page() and ra_node_pages()
> > > that I suggested.
> > > So how about reading node pages and then caching some of them in the
> > > page cache, node_inode's address space?
> >
> > Got it,
> > If we do not use the method above, we should search the NAT for nid number
> > as the index of node_inode's page by the specified node page blkaddr, that costs
> > a lot.
> > How do you think?
>
> 1. grab_cache_page(node_footer->nid);
> 2. memcpy();
> 3. SetPageUptodate();
> 4. f2fs_put_page();
It could be.
This make ra_node_pages() synchronized, because we should read node_footer->nid
from updated node page before we cache node pages, and we will still use page list to
pass the updated page.
Why not introduce f2fs_cache_node_pages() include your code to cache node pages after
ra_node_pages()?
Thanks,
Yu
>
> Thanks,
>
> >
> > >
> > > Thanks,
> > >
> > > >
> > > >
> > > > >
> > > > > Thanks,
> > > > >
> > > > > 2013-11-22 (금), 15:48 +0800, Chao Yu:
> > > > > > If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
> > > > > > one by one, it makes low performance. So let's merge contiguous pages and
> > > > > > readahead for better performance.
> > > > > >
> > > > > > Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> > > > > > ---
> > > > > > fs/f2fs/node.c | 89 +++++++++++++++++++++++++++++++++++++++-----------------
> > > > > > 1 file changed, 63 insertions(+), 26 deletions(-)
> > > > > >
> > > > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > > > > > index 4ac4150..81e704a 100644
> > > > > > --- a/fs/f2fs/node.c
> > > > > > +++ b/fs/f2fs/node.c
> > > > > > @@ -1572,47 +1572,84 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> > > > > > return 0;
> > > > > > }
> > > > > >
> > > > > > +/*
> > > > > > + * ra_sum_pages() merge contiguous pages into one bio and submit.
> > > > > > + * these pre-readed pages are linked in pages list.
> > > > > > + */
> > > > > > +static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
> > > > > > + int start, int nrpages)
> > > > > > +{
> > > > > > + struct page *page;
> > > > > > + int page_idx = start;
> > > > > > +
> > > > > > + for (; page_idx < start + nrpages; page_idx++) {
> > > > > > + /* alloc temporal page for read node summary info*/
> > > > > > + page = alloc_page(GFP_NOFS | __GFP_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;
> > > > > > + }
> > > > > > +
> > > > > > + lock_page(page);
> > > > > > + page->index = page_idx;
> > > > > > + list_add_tail(&page->lru, pages);
> > > > > > + }
> > > > > > +
> > > > > > + list_for_each_entry(page, pages, lru)
> > > > > > + submit_read_page(sbi, page, page->index, READ_SYNC);
> > > > > > +
> > > > > > + f2fs_submit_read_bio(sbi, READ_SYNC);
> > > > > > + return 0;
> > > > > > +}
> > > > > > +
> > > > > > int restore_node_summary(struct f2fs_sb_info *sbi,
> > > > > > unsigned int segno, struct f2fs_summary_block *sum)
> > > > > > {
> > > > > > struct f2fs_node *rn;
> > > > > > struct f2fs_summary *sum_entry;
> > > > > > - struct page *page;
> > > > > > + struct page *page, *tmp;
> > > > > > block_t addr;
> > > > > > - int i, last_offset;
> > > > > > -
> > > > > > - /* alloc temporal page for read node */
> > > > > > - page = alloc_page(GFP_NOFS | __GFP_ZERO);
> > > > > > - if (!page)
> > > > > > - return -ENOMEM;
> > > > > > - lock_page(page);
> > > > > > + int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> > > > > > + int i, last_offset, nrpages, err = 0;
> > > > > > + LIST_HEAD(page_list);
> > > > > >
> > > > > > /* scan the node segment */
> > > > > > last_offset = sbi->blocks_per_seg;
> > > > > > addr = START_BLOCK(sbi, segno);
> > > > > > sum_entry = &sum->entries[0];
> > > > > >
> > > > > > - for (i = 0; i < last_offset; i++, sum_entry++) {
> > > > > > - /*
> > > > > > - * In order to read next node page,
> > > > > > - * we must clear PageUptodate flag.
> > > > > > - */
> > > > > > - ClearPageUptodate(page);
> > > > > > + for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
> > > > > >
> > > > > > - if (f2fs_readpage(sbi, page, addr, READ_SYNC))
> > > > > > - goto out;
> > > > > > + nrpages = min(last_offset - i, bio_blocks);
> > > > > > + /* read ahead node pages */
> > > > > > + err = ra_sum_pages(sbi, &page_list, addr, nrpages);
> > > > > > + if (err)
> > > > > > + return err;
> > > > > >
> > > > > > - lock_page(page);
> > > > > > - rn = F2FS_NODE(page);
> > > > > > - sum_entry->nid = rn->footer.nid;
> > > > > > - sum_entry->version = 0;
> > > > > > - sum_entry->ofs_in_node = 0;
> > > > > > - addr++;
> > > > > > + list_for_each_entry_safe(page, tmp, &page_list, lru) {
> > > > > > +
> > > > > > + lock_page(page);
> > > > > > + if(PageUptodate(page)) {
> > > > > > + rn = F2FS_NODE(page);
> > > > > > + sum_entry->nid = rn->footer.nid;
> > > > > > + sum_entry->version = 0;
> > > > > > + sum_entry->ofs_in_node = 0;
> > > > > > + sum_entry++;
> > > > > > + } else {
> > > > > > + err = -EIO;
> > > > > > + }
> > > > > > +
> > > > > > + list_del(&page->lru);
> > > > > > + unlock_page(page);
> > > > > > + __free_pages(page, 0);
> > > > > > + }
> > > > > > }
> > > > > > - unlock_page(page);
> > > > > > -out:
> > > > > > - __free_pages(page, 0);
> > > > > > - return 0;
> > > > > > + return err;
> > > > > > }
> > > > > >
> > > > > > static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
> > > > >
> > > > > --
> > > > > Jaegeuk Kim
> > > > > Samsung
> > > >
> > >
> > > --
> > > Jaegeuk Kim
> > > Samsung
> >
>
> --
> Jaegeuk Kim
> Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary
2013-11-28 5:56 ` Chao Yu
@ 2013-11-30 5:12 ` Jaegeuk Kim
0 siblings, 0 replies; 8+ messages in thread
From: Jaegeuk Kim @ 2013-11-30 5:12 UTC (permalink / raw)
To: Chao Yu
Cc: linux-fsdevel, linux-kernel, linux-f2fs-devel,
'谭姝'
Hi,
[snip]
> > > So how about add all pages of page list to node_inode's address space by
> > > add_to_page_cache_lru() with arg sum_entry->nid?
> >
> > I don't think it's proper way to use add_to_page_cache_lru() directly.
>
> This is the way used in VM readahead(i.e. read_pages/mpage_readpages/
> read_cache_pages).
> So what you worry about is that using lonely add_to_page_cache_lru()
> may cause exception, is it?
Right, what I meant was that, IMO, we should avoid copy and paste MM
codes, but use its wrappers, exported symbols, as much as possible.
> > > > > >
> > > > > > So how about writing ra_node_pages() which use the node_inode's page
> > > > > > cache?
> > > > >
> > > > > Hmm, so ra_node_pages is introduced for read node_inode's pages which are
> > > > > logical contiguously? and it also could take place of ra_node_page?
> > > >
> > > > Ah. The ra_node_page() read a node page ahead for a given node id.
> > > > So it doesn't match exactly between ra_node_page() and ra_node_pages()
> > > > that I suggested.
> > > > So how about reading node pages and then caching some of them in the
> > > > page cache, node_inode's address space?
> > >
> > > Got it,
> > > If we do not use the method above, we should search the NAT for nid number
> > > as the index of node_inode's page by the specified node page blkaddr, that costs
> > > a lot.
> > > How do you think?
> >
> > 1. grab_cache_page(node_footer->nid);
> > 2. memcpy();
> > 3. SetPageUptodate();
> > 4. f2fs_put_page();
>
> It could be.
>
> This make ra_node_pages() synchronized, because we should read node_footer->nid
> from updated node page before we cache node pages, and we will still use page list to
> pass the updated page.
>
> Why not introduce f2fs_cache_node_pages() include your code to cache node pages after
> ra_node_pages()?
Ok, right.
I'll test again and then merge this patch. :)
--
Jaegeuk Kim
Samsung
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2013-11-30 5:13 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-11-22 7:48 [f2fs-dev] [PATCH] f2fs: readahead contiguous pages for restore_node_summary Chao Yu
2013-11-27 5:29 ` Jaegeuk Kim
2013-11-27 7:58 ` Chao Yu
2013-11-27 8:19 ` Jaegeuk Kim
2013-11-28 1:26 ` Chao Yu
2013-11-28 3:33 ` Jaegeuk Kim
2013-11-28 5:56 ` Chao Yu
2013-11-30 5:12 ` Jaegeuk Kim
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