[PATCH] strbuf_write: omit system call when length is zero

Subsystems: the rest

STALE3738d

2 messages, 2 authors, 2016-06-15 · open the first message on its own page

[PATCH] strbuf_write: omit system call when length is zero

From: Stefan Beller <hidden>
Date: 2016-06-15 23:08:28

In case the length of the buffer is zero, we do not need to call the
fwrite system call as a performance improvement.

Signed-off-by: Stefan Beller <redacted>
---

 This applies on top of v17 for origin/sb/submodule-parallel-update.
 
 In case there are other reasons for origin/sb/submodule-parallel-update
 to need a reroll I'll squash it in. But as this is a pure performance
 optimization in a case we are not running into with that series and that
 series is clashing with Davids refs backend series, I figure we may not
 want to have a reroll for this fix alone.
 
 Thanks,
 Stefan
  

 strbuf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/strbuf.c b/strbuf.c
index 71345cd..5f6da82 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -397,7 +397,7 @@ ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)
 
 ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 {
-	return fwrite(sb->buf, 1, sb->len, f);
+	return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 }
 
 
-- 
2.7.2.374.ga5f0819.dirty

Re: [PATCH] strbuf_write: omit system call when length is zero

From: Duy Nguyen <hidden>
Date: 2016-06-15 23:08:29

On Fri, Feb 26, 2016 at 5:34 AM, Stefan Beller [off-list ref] wrote:
In case the length of the buffer is zero, we do not need to call the
fwrite system call as a performance improvement.
fwrite is a libc call, not system call. Are you sure it always calls
write() (assuming buffering is off)?
quoted hunk
Signed-off-by: Stefan Beller <redacted>
---

 This applies on top of v17 for origin/sb/submodule-parallel-update.

 In case there are other reasons for origin/sb/submodule-parallel-update
 to need a reroll I'll squash it in. But as this is a pure performance
 optimization in a case we are not running into with that series and that
 series is clashing with Davids refs backend series, I figure we may not
 want to have a reroll for this fix alone.

 Thanks,
 Stefan


 strbuf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/strbuf.c b/strbuf.c
index 71345cd..5f6da82 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -397,7 +397,7 @@ ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)

 ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 {
-       return fwrite(sb->buf, 1, sb->len, f);
+       return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 }


--
2.7.2.374.ga5f0819.dirty

--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html


-- 
Duy
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help