From: Tejun Heo <tj@kernel.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>,
ShuoX Liu <shuox.liu@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Christoph Lameter <cl@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH] percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bit
Date: Fri, 27 Apr 2012 10:27:31 -0700 [thread overview]
Message-ID: <20120427172731.GD26595@google.com> (raw)
In-Reply-To: <4F9AD49D.6080406@zytor.com>
On Fri, Apr 27, 2012 at 10:17:17AM -0700, H. Peter Anvin wrote:
> On 04/27/2012 09:53 AM, Tejun Heo wrote:
> >
> > + /*
> > + * If PSE is available, use PMD_SIZE for atom_size so that
> > + * embedded percpu areas are aligned to PMD. This, in the
> > + * future, can also allow using PMD mappings in vmalloc
> > + * area. Use PAGE_SIZE on 32bit as vmalloc space is highly
> > + * contended and large vmalloc area alloc can easily fail.
> > + */
> > + atom_size = PAGE_SIZE;
> > +#ifdef CONFIG_X86_64
> > + if (cpu_has_pse)
> > + atom_size = PMD_SIZE;
> > +#endif
>
> Just make it PAGE_SIZE on i386 and PMD_SIZE on x86-64; keep the behavior
> consistent. !cpu_has_pse on x86-64 is an abnormal situation (I think it
> applies to Xen, pretty much.)
>
> Other than that,
>
> Acked-by: H. Peter Anvin <hpa@zytor.com>
Yeah, that's simpler. Will update.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-04-27 17:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-25 8:49 [PATCH] mm: percpu: Add PCPU_FC_FIXED to pcpu_fc for setting fixed pcpu_atom_size ShuoX Liu
2012-04-25 22:24 ` Tejun Heo
2012-04-26 2:01 ` Yanmin Zhang
2012-04-26 22:49 ` Tejun Heo
2012-04-27 1:09 ` Yanmin Zhang
2012-04-27 8:56 ` Yanmin Zhang
2012-04-27 16:53 ` [PATCH] percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bit Tejun Heo
2012-04-27 17:17 ` H. Peter Anvin
2012-04-27 17:27 ` Tejun Heo [this message]
2012-04-27 17:21 ` Christoph Lameter
2012-04-27 17:27 ` Tejun Heo
2012-04-27 17:39 ` [PATCH v2] " Tejun Heo
2012-04-27 17:51 ` H. Peter Anvin
2012-04-27 17:53 ` Tejun Heo
2012-04-28 2:18 ` [PATCH] " ShuoX Liu
2012-04-27 16:34 ` [PATCH] mm: percpu: Add PCPU_FC_FIXED to pcpu_fc for setting fixed pcpu_atom_size Tejun Heo
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