From: Mel Gorman <mgorman@techsingularity.net>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>, Jan Kara <jack@suse.cz>,
Linux-FSDevel <linux-fsdevel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 1/2] mm: filemap: Remove redundant code in do_read_cache_page
Date: Tue, 26 Jan 2016 14:09:29 +0000 [thread overview]
Message-ID: <1453817370-10399-2-git-send-email-mgorman@techsingularity.net> (raw)
In-Reply-To: <1453817370-10399-1-git-send-email-mgorman@techsingularity.net>
do_read_cache_page and __read_cache_page duplicates page filler code
when filling the page for the first time. This patch simply removes the
duplicate logic.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Jan Kara <jack@suse.cz>
---
mm/filemap.c | 43 ++++++++++++-------------------------------
1 file changed, 12 insertions(+), 31 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index bc943867d68c..aa38593d0cd5 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2283,7 +2283,7 @@ static struct page *wait_on_page_read(struct page *page)
return page;
}
-static struct page *__read_cache_page(struct address_space *mapping,
+static struct page *do_read_cache_page(struct address_space *mapping,
pgoff_t index,
int (*filler)(void *, struct page *),
void *data,
@@ -2305,31 +2305,19 @@ static struct page *__read_cache_page(struct address_space *mapping,
/* Presumably ENOMEM for radix tree node */
return ERR_PTR(err);
}
+
+filler:
err = filler(data, page);
if (err < 0) {
page_cache_release(page);
- page = ERR_PTR(err);
- } else {
- page = wait_on_page_read(page);
+ return ERR_PTR(err);
}
- }
- return page;
-}
-
-static struct page *do_read_cache_page(struct address_space *mapping,
- pgoff_t index,
- int (*filler)(void *, struct page *),
- void *data,
- gfp_t gfp)
-
-{
- struct page *page;
- int err;
-retry:
- page = __read_cache_page(mapping, index, filler, data, gfp);
- if (IS_ERR(page))
- return page;
+ page = wait_on_page_read(page);
+ if (IS_ERR(page))
+ return page;
+ goto out;
+ }
if (PageUptodate(page))
goto out;
@@ -2337,21 +2325,14 @@ static struct page *do_read_cache_page(struct address_space *mapping,
if (!page->mapping) {
unlock_page(page);
page_cache_release(page);
- goto retry;
+ goto repeat;
}
if (PageUptodate(page)) {
unlock_page(page);
goto out;
}
- err = filler(data, page);
- if (err < 0) {
- page_cache_release(page);
- return ERR_PTR(err);
- } else {
- page = wait_on_page_read(page);
- if (IS_ERR(page))
- return page;
- }
+ goto filler;
+
out:
mark_page_accessed(page);
return page;
--
2.6.4
next prev parent reply other threads:[~2016-01-26 14:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-26 14:09 [PATCH 0/2] Avoid unnecessary page locks in the generic read path v2r1 Mel Gorman
2016-01-26 14:09 ` Mel Gorman [this message]
2016-01-26 14:09 ` [PATCH 2/2] mm: filemap: Avoid unnecessary calls to lock_page when waiting for IO to complete during a read Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2016-01-25 10:03 [PATCH 0/2] Avoid unnecessary page locks in the generic read path Mel Gorman
2016-01-25 10:03 ` [PATCH 1/2] mm: filemap: Remove redundant code in do_read_cache_page Mel Gorman
2016-01-25 11:35 ` Jan Kara
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