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From: David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
To: dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Cc: harvey.harrison-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org
Subject: Re: [PATCH 2/2] kernel: Move arches to use common unaligned access
Date: Fri, 11 Apr 2008 03:16:42 -0700 (PDT)	[thread overview]
Message-ID: <20080411.031642.193716019.davem@davemloft.net> (raw)
In-Reply-To: <15208.1207908688-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

From: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Date: Fri, 11 Apr 2008 11:11:28 +0100

> Harvey Harrison <harvey.harrison-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 
> > - * impractical.  So, now we fall back to using memcpy.
> > + * impractical.  So, now we fall back to using memmov.
> 
> That's memmove, not memmov.  Any why memmove, not memcpy?  Is __tmp likely to
> overlap with *ptr?

No, I think it has something to do with what cases GCC is allowed to
optimize the call inline and what cases it cannot wrt.  alignment of
datums.

WARNING: multiple messages have this Message-ID (diff)
From: David Miller <davem@davemloft.net>
To: dhowells@redhat.com
Cc: harvey.harrison@gmail.com, akpm@linux-foundation.org,
	linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	torvalds@linux-foundation.org
Subject: Re: [PATCH 2/2] kernel: Move arches to use common unaligned access
Date: Fri, 11 Apr 2008 03:16:42 -0700 (PDT)	[thread overview]
Message-ID: <20080411.031642.193716019.davem@davemloft.net> (raw)
Message-ID: <20080411101642.Vn7fU3EzN_b_mdc2T66XBKSiUIRA-W4HkG_gZj0UYNk@z> (raw)
In-Reply-To: <15208.1207908688@redhat.com>

From: David Howells <dhowells@redhat.com>
Date: Fri, 11 Apr 2008 11:11:28 +0100

> Harvey Harrison <harvey.harrison@gmail.com> wrote:
> 
> > - * impractical.  So, now we fall back to using memcpy.
> > + * impractical.  So, now we fall back to using memmov.
> 
> That's memmove, not memmov.  Any why memmove, not memcpy?  Is __tmp likely to
> overlap with *ptr?

No, I think it has something to do with what cases GCC is allowed to
optimize the call inline and what cases it cannot wrt.  alignment of
datums.

  parent reply	other threads:[~2008-04-11 10:16 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-11  3:38 [PATCH 2/2] kernel: Move arches to use common unaligned access Harvey Harrison
2008-04-11  3:38 ` Harvey Harrison
2008-04-11  7:48 ` Ingo Molnar
2008-04-11  7:48   ` Ingo Molnar
2008-04-11 10:11 ` David Howells
2008-04-11 10:11   ` David Howells
     [not found]   ` <15208.1207908688-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2008-04-11 10:16     ` David Miller [this message]
2008-04-11 10:16       ` David Miller
2008-04-11 10:27       ` David Howells
2008-04-11 10:27         ` David Howells
2008-04-11 15:19     ` Harvey Harrison
2008-04-11 15:19       ` Harvey Harrison
2008-04-11 15:50       ` David Howells
2008-04-11 15:50         ` David Howells
     [not found]         ` <2225.1207929050-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2008-04-11 17:31           ` Harvey Harrison
2008-04-11 17:31             ` Harvey Harrison
2008-04-11 17:55           ` [PATCH 2/2-revised] " Harvey Harrison
2008-04-11 17:55             ` Harvey Harrison

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