All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Ross Zwisler <ross.zwisler@linux.intel.com>
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 12:09:51 +0100	[thread overview]
Message-ID: <20150312110950.GA8475@gmail.com> (raw)
In-Reply-To: <1426107899-27933-1-git-send-email-ross.zwisler@linux.intel.com>


* 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.


Thanks,

	Ingo

  reply	other threads:[~2015-03-12 11:09 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 [this message]
2015-03-13  2:00   ` Ross Zwisler
2015-04-28 22:13 Ross Zwisler
2015-04-29 10:28 ` Borislav Petkov

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=20150312110950.GA8475@gmail.com \
    --to=mingo@kernel.org \
    --cc=bp@suse.de \
    --cc=dan.j.williams@intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=ross.zwisler@linux.intel.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.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.