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From: Ross Zwisler <ross.zwisler@linux.intel.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, Dan Williams <dan.j.williams@intel.com>,
	Borislav Petkov <bp@suse.de>
Subject: Re: [PATCH] x86: improve algorithm in clflush_cache_range
Date: Thu, 12 Mar 2015 20:00:26 -0600	[thread overview]
Message-ID: <1426212026.14865.2.camel@theros.lm.intel.com> (raw)
In-Reply-To: <20150312110950.GA8475@gmail.com>

On Thu, 2015-03-12 at 12:09 +0100, Ingo Molnar wrote:
> * Ross Zwisler <ross.zwisler@linux.intel.com> wrote:
> 
> > The current algorithm used in clflush_cache_range() can cause the last
> > cache line of the buffer to be flushed twice.
> > 
> > Fix that algorithm so that each cache line will only be flushed once,
> > and remove arithmetic on void pointers.  Void pointer arithmetic is
> > allowed by GCC extensions, but isn't part of the base C standards.
> 
> The optimization itself is fine, but that last argument is bogus: the 
> Linux kernel very much relies on 'void *' arithmetics in a gazillion 
> places.

Okay.  Are you happy with the patch as is or would you like me to
resubmit with that bit omitted from the change log?

- Ross


  reply	other threads:[~2015-03-13  2:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-11 21:04 [PATCH] x86: improve algorithm in clflush_cache_range Ross Zwisler
2015-03-12 11:09 ` Ingo Molnar
2015-03-13  2:00   ` Ross Zwisler [this message]
  -- strict thread matches above, loose matches on Subject: below --
2015-04-28 22:13 Ross Zwisler
2015-04-29 10:28 ` Borislav Petkov

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