NetBSD Problem Report #50900
From www@NetBSD.org Sun Mar 6 17:45:06 2016
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Message-Id: <20160306174505.4E2BF7ACC5@mollari.NetBSD.org>
Date: Sun, 6 Mar 2016 17:45:05 +0000 (UTC)
From: dcb314@hotmail.com
Reply-To: dcb314@hotmail.com
To: gnats-bugs@NetBSD.org
Subject: src/sys/rump/librump/rumpvfs/rumpfs.c:936: clumsy call to memset ?
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>Number: 50900
>Category: kern
>Synopsis: src/sys/rump/librump/rumpvfs/rumpfs.c:936: clumsy call to memset ?
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: kern-bug-people
>State: closed
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sun Mar 06 17:50:00 +0000 2016
>Closed-Date: Sun Mar 06 20:13:56 +0000 2016
>Last-Modified: Sun Mar 06 20:13:56 +0000 2016
>Originator: David Binderman
>Release: cvs dated 20160305
>Organization:
>Environment:
>Description:
[src/sys/rump/librump/rumpvfs/rumpfs.c:936] -> [src/sys/rump/librump/rumpvfs/rumpfs.c:937]: (performance) Buffer 'newdata' is being written before its old content has been used.
Source code is
copylen = MIN(rn->rn_dlen, newlen);
memset(newdata, 0, newlen);
memcpy(newdata, rn->rn_data, copylen);
This could be coded up in a faster fashion,
Suggest only zero those bytes that the memcpy doesn't touch.
>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
From: "Christos Zoulas" <christos@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc:
Subject: PR/50900 CVS commit: src/sys/rump/librump/rumpvfs
Date: Sun, 6 Mar 2016 14:47:41 -0500
Module Name: src
Committed By: christos
Date: Sun Mar 6 19:47:41 UTC 2016
Modified Files:
src/sys/rump/librump/rumpvfs: rumpfs.c
Log Message:
PR/50900: David Binderman: optimize memset
To generate a diff of this commit:
cvs rdiff -u -r1.138 -r1.139 src/sys/rump/librump/rumpvfs/rumpfs.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
State-Changed-From-To: open->closed
State-Changed-By: wiz@NetBSD.org
State-Changed-When: Sun, 06 Mar 2016 20:13:56 +0000
State-Changed-Why:
Fixed by christos, thanks!
>Unformatted:
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