From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Andi Kleen <ak@linux.intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Alex Shi <alex.shu@intel.com>, Jan Beulich <jbeulich@novell.com>,
Robert Richter <robert.richter@amd.com>,
Andy Lutomirski <luto@amacapital.net>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Mel Gorman <mgorman@suse.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH, RFC 0/6] Avoid cache trashing on clearing huge/gigantic page
Date: Tue, 24 Jul 2012 17:09:11 +0300 [thread overview]
Message-ID: <20120724140911.GA8270@otc-wbsnb-06> (raw)
In-Reply-To: <20120723163020.5250e09e.akpm@linux-foundation.org>
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On Mon, Jul 23, 2012 at 04:30:20PM -0700, Andrew Morton wrote:
> On Fri, 20 Jul 2012 15:50:16 +0300
> "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> wrote:
>
> > Clearing a 2MB huge page will typically blow away several levels of CPU
> > caches. To avoid this only cache clear the 4K area around the fault
> > address and use a cache avoiding clears for the rest of the 2MB area.
> >
> > It would be nice to test the patchset with more workloads. Especially if
> > you see performance regression with THP.
> >
> > Any feedback is appreciated.
>
> This all looks pretty sane to me. Some detail-poking from the x86 guys
> would be nice.
>
> What do other architectures need to do? Simply implement
> clear_page_nocache()?
And define ARCH_HAS_USER_NOCACHE to 1.
> I believe that powerpc is one, not sure about
> others. Please update the changelogs to let arch maintainers know
> what they should do and cc those people on future versions?
Okay.
--
Kirill A. Shutemov
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next prev parent reply other threads:[~2012-07-24 14:07 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-20 12:50 [PATCH, RFC 0/6] Avoid cache trashing on clearing huge/gigantic page Kirill A. Shutemov
2012-07-20 12:50 ` [PATCH, RFC 1/6] THP: Use real address for NUMA policy Kirill A. Shutemov
2012-07-20 12:50 ` [PATCH, RFC 2/6] mm: make clear_huge_page tolerate non aligned address Kirill A. Shutemov
2012-07-20 12:50 ` [PATCH, RFC 3/6] THP: Pass real, not rounded, address to clear_huge_page Kirill A. Shutemov
2012-07-20 12:50 ` [PATCH, RFC 4/6] x86: Add clear_page_nocache Kirill A. Shutemov
2012-07-20 12:50 ` [PATCH, RFC 5/6] mm: make clear_huge_page cache clear only around the fault address Kirill A. Shutemov
2012-07-20 12:50 ` [PATCH, RFC 6/6] x86: switch the 64bit uncached page clear to SSE/AVX v2 Kirill A. Shutemov
2012-07-23 23:30 ` [PATCH, RFC 0/6] Avoid cache trashing on clearing huge/gigantic page Andrew Morton
2012-07-24 14:09 ` Kirill A. Shutemov [this message]
2012-07-25 18:51 ` Christoph Lameter
2012-07-25 19:28 ` Andi Kleen
2012-07-25 19:38 ` Christoph Lameter
2012-08-09 15:18 ` H. Peter Anvin
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