From: Andi Kleen <andi@firstfloor.org>
To: Thomas Hellstrom <thellstrom@vmware.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
venkatesh.pallipadi@intel.com
Subject: Re: [PATCH] x86: Use clflush() instead of wbinvd() whenever possible when changing mapping
Date: Fri, 24 Jul 2009 12:05:01 +0200 [thread overview]
Message-ID: <87ocra1jn6.fsf@basil.nowhere.org> (raw)
In-Reply-To: <1248421981-31865-1-git-send-email-thellstrom@vmware.com> (Thomas Hellstrom's message of "Fri, 24 Jul 2009 09:53:01 +0200")
Thomas Hellstrom <thellstrom@vmware.com> writes:
> The current code uses wbinvd() when the area to flush is > 4MB. Although this
> may be faster than using clflush() the effect of wbinvd() on irq latencies
> may be catastrophical on systems with large caches. Therefore use clflush()
may be? You seem to miss some hard data here.
I wouldn't expect wbinvd to take longer than a ms or two, which
is probably not catastrophic yet.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-07-24 10:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-24 7:53 [PATCH] x86: Use clflush() instead of wbinvd() whenever possible when changing mapping Thomas Hellstrom
2009-07-24 10:05 ` Andi Kleen [this message]
2009-07-24 10:21 ` Thomas Hellstrom
2009-07-24 10:58 ` Andi Kleen
2009-07-24 11:14 ` Thomas Hellstrom
2009-07-24 13:16 ` Andi Kleen
2009-07-30 9:07 ` Pavel Machek
2009-08-02 16:22 ` Thomas Hellström
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