From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Date: Fri, 15 Oct 2004 01:18:38 +0000 Subject: Re: [PATCH] General purpose zeroed page slab Message-Id: <20041015011838.GC9753@wotan.suse.de> List-Id: References: <20041014180427.GA7973@wotan.suse.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Adam Heath Cc: Andi Kleen , "Martin K. Petersen" , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, akpm@osdl.org, tony.luck@intel.com On Thu, Oct 14, 2004 at 06:36:47PM -0500, Adam Heath wrote: > On Thu, 14 Oct 2004, Andi Kleen wrote: > > > Also that's pretty dumb. How about keeping track how much of the > > page got non zeroed (e.g. by using a few free words in struct page > > for a coarse grained dirty bitmap) > > > > Then you could memset on free only the parts that got actually > > changed, and never waste cache lines for anything else. > > That will fail when a struct is placed in the page, and only the beginning and > end of the struct was changed. Hmm? I think you're misunderstanding me. The dirty bitmap would cover all areas that are potentially not zero. If someone changes a byte without setting the bitmap they're buggy. -Andi >