From: Andi Kleen <ak@suse.de>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jes Sorensen <jes@sgi.com>, Linus Torvalds <torvalds@osdl.org>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: [patch] avoid unaligned access when accessing poll stack
Date: Fri, 31 Mar 2006 16:53:32 +0000 [thread overview]
Message-ID: <200603311853.32870.ak@suse.de> (raw)
In-Reply-To: <87irpupo3y.fsf@duaron.myhome.or.jp>
On Friday 31 March 2006 18:37, OGAWA Hirofumi wrote:
> Jes Sorensen <jes@sgi.com> writes:
>
> > struct poll_list *walk;
> > struct fdtable *fdt;
> > int max_fdset;
> > - /* Allocate small arguments on the stack to save memory and be faster */
> > - char stack_pps[POLL_STACK_ALLOC];
> > + /* Allocate small arguments on the stack to save memory and be
> > + faster - use long to make sure the buffer is aligned properly
> > + on 64 bit archs to avoid unaligned access */
> > + long stack_pps[POLL_STACK_ALLOC/sizeof(long)];
> > struct poll_list *stack_pp = NULL;
>
> struct poll_list stack_pps[POLL_STACK_ALLOC / sizeof(struct poll_list)];
>
> is more readable, and probably gcc align it rightly?
Yes, but it would be wrong
-Andi
WARNING: multiple messages have this Message-ID (diff)
From: Andi Kleen <ak@suse.de>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jes Sorensen <jes@sgi.com>, Linus Torvalds <torvalds@osdl.org>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: [patch] avoid unaligned access when accessing poll stack
Date: Fri, 31 Mar 2006 18:53:32 +0200 [thread overview]
Message-ID: <200603311853.32870.ak@suse.de> (raw)
In-Reply-To: <87irpupo3y.fsf@duaron.myhome.or.jp>
On Friday 31 March 2006 18:37, OGAWA Hirofumi wrote:
> Jes Sorensen <jes@sgi.com> writes:
>
> > struct poll_list *walk;
> > struct fdtable *fdt;
> > int max_fdset;
> > - /* Allocate small arguments on the stack to save memory and be faster */
> > - char stack_pps[POLL_STACK_ALLOC];
> > + /* Allocate small arguments on the stack to save memory and be
> > + faster - use long to make sure the buffer is aligned properly
> > + on 64 bit archs to avoid unaligned access */
> > + long stack_pps[POLL_STACK_ALLOC/sizeof(long)];
> > struct poll_list *stack_pp = NULL;
>
> struct poll_list stack_pps[POLL_STACK_ALLOC / sizeof(struct poll_list)];
>
> is more readable, and probably gcc align it rightly?
Yes, but it would be wrong
-Andi
next prev parent reply other threads:[~2006-03-31 16:53 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-31 15:38 [patch] avoid unaligned access when accessing poll stack Jes Sorensen
2006-03-31 15:38 ` Jes Sorensen
2006-03-31 16:00 ` Andi Kleen
2006-03-31 16:00 ` Andi Kleen
2006-03-31 16:18 ` Jes Sorensen
2006-03-31 16:18 ` Jes Sorensen
2006-04-01 2:35 ` Mitchell Blank Jr
2006-04-01 2:35 ` Mitchell Blank Jr
2006-04-01 2:44 ` Andi Kleen
2006-04-01 2:44 ` Andi Kleen
2006-04-01 3:39 ` Mitchell Blank Jr
2006-04-01 3:39 ` Mitchell Blank Jr
2006-03-31 16:37 ` OGAWA Hirofumi
2006-03-31 16:37 ` OGAWA Hirofumi
2006-03-31 16:53 ` Andi Kleen [this message]
2006-03-31 16:53 ` Andi Kleen
2006-03-31 17:16 ` OGAWA Hirofumi
2006-03-31 17:16 ` OGAWA Hirofumi
2006-03-31 17:18 ` Andi Kleen
2006-03-31 17:18 ` Andi Kleen
2006-03-31 17:40 ` OGAWA Hirofumi
2006-03-31 17:40 ` OGAWA Hirofumi
2006-03-31 17:19 ` OGAWA Hirofumi
2006-03-31 17:19 ` OGAWA Hirofumi
2006-03-31 18:20 ` Andrew Morton
2006-03-31 18:20 ` Andrew Morton
2006-04-02 14:49 ` Jes Sorensen
2006-04-02 14:49 ` Jes Sorensen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=200603311853.32870.ak@suse.de \
--to=ak@suse.de \
--cc=akpm@osdl.org \
--cc=hirofumi@mail.parknet.co.jp \
--cc=jes@sgi.com \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@osdl.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.