From: Bean Huo <huobean@gmail.com>
To: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Cc: beanhuo@micron.com
Subject: [PATCH RFC] mm: Let readahead submit larger batches of pages in case of ra->ra_pages == 0
Date: Fri, 4 Sep 2020 16:48:07 +0200 [thread overview]
Message-ID: <20200904144807.31810-1-huobean@gmail.com> (raw)
From: Bean Huo <beanhuo@micron.com>
Current generic_file_buffered_read() will break up the larger batches of pages
and read data in single page length in case of ra->ra_pages == 0. This patch is
to allow it to pass the batches of pages down to the device if the supported
maximum IO size >= the requested size.
Signed-off-by: Bean Huo <beanhuo@micron.com>
---
mm/filemap.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 1aaea26556cc..0deec1897817 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2062,6 +2062,7 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
struct file *filp = iocb->ki_filp;
struct address_space *mapping = filp->f_mapping;
struct inode *inode = mapping->host;
+ struct backing_dev_info *bdi = inode_to_bdi(mapping->host);
struct file_ra_state *ra = &filp->f_ra;
loff_t *ppos = &iocb->ki_pos;
pgoff_t index;
@@ -2098,9 +2099,14 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
if (!page) {
if (iocb->ki_flags & IOCB_NOIO)
goto would_block;
- page_cache_sync_readahead(mapping,
- ra, filp,
- index, last_index - index);
+
+ if (!ra->ra_pages && bdi->io_pages >= last_index - index)
+ __do_page_cache_readahead(mapping, filp, index,
+ last_index - index, 0);
+ else
+ page_cache_sync_readahead(mapping, ra, filp,
+ index,
+ last_index - index);
page = find_get_page(mapping, index);
if (unlikely(page == NULL))
goto no_cached_page;
--
2.17.1
next reply other threads:[~2020-09-04 14:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 14:48 Bean Huo [this message]
2020-09-04 18:09 ` [PATCH RFC] mm: Let readahead submit larger batches of pages in case of ra->ra_pages == 0 Andrew Morton
2020-09-11 8:15 ` Bean Huo
2020-09-11 9:47 ` Christoph Hellwig
2020-09-11 11:35 ` Bean Huo
2020-09-11 11:36 ` Bean Huo
2020-09-07 7:16 ` Christoph Hellwig
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