From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] memory page_alloc zonelist caching speedup aligncache From: Rohit Seth Reply-To: rohitseth@google.com In-Reply-To: <20061018081440.18477.10664.sendpatchset@sam.engr.sgi.com> References: <20061018081440.18477.10664.sendpatchset@sam.engr.sgi.com> Content-Type: text/plain Date: Wed, 18 Oct 2006 08:35:37 -0700 Message-Id: <1161185737.582.326.camel@galaxy.corp.google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Jackson Cc: akpm@osdl.org, nickpiggin@yahoo.com.au, ak@suse.de, linux-mm@kvack.org, holt@sgi.com, mbligh@google.com, rientjes@google.com, menage@google.com, clameter@sgi.com List-ID: On Wed, 2006-10-18 at 01:14 -0700, Paul Jackson wrote: > From: Paul Jackson > > Avoid frequent writes to the zonelist zones[] array, which are > read-only after initial setup, by putting the zonelist_cache on > a separate cacheline. > > Signed-off-by: Paul Jackson > > --- > > include/linux/mmzone.h | 3 ++- > 1 files changed, 2 insertions(+), 1 deletion(-) > > --- 2.6.19-rc2-mm1.orig/include/linux/mmzone.h 2006-10-17 17:19:22.000000000 -0700 > +++ 2.6.19-rc2-mm1/include/linux/mmzone.h 2006-10-17 17:31:31.000000000 -0700 > @@ -396,7 +396,8 @@ struct zonelist { > struct zonelist_cache *zlcache_ptr; // NULL or &zlcache > struct zone *zones[MAX_ZONES_PER_ZONELIST + 1]; // NULL delimited > #ifdef CONFIG_NUMA > - struct zonelist_cache zlcache; // optional ... > + /* Keep written zonelist_cache off read-only zones[] cache lines */ > + struct zonelist_cache zlcache ____cacheline_aligned; // optional ... > #endif > }; > > Wouldn't it be better to have the read mostly field z_to_n defined first in zonelist_cache (and define the BITMAP at the end). -rohit -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org