From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Date: Fri, 10 Jun 2005 17:13:41 +0000 Subject: Re: [RFD] Separating struct task and the kernel stacks Message-Id: <20050610171341.GG24611@parcelfarce.linux.theplanet.co.uk> List-Id: References: <9712.1118384111@kao2.melbourne.sgi.com> In-Reply-To: <9712.1118384111@kao2.melbourne.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Fri, Jun 10, 2005 at 08:11:42AM -0700, Christoph Lameter wrote: > Using the slab allocator generates a certain amount of overhead during > process creation. I believe the page allocator would be faster. Also there > needs to be no separate allocation of memory for the stack. While speed of process creation is certainly an important benchmark, speed of scheduling is more important. I was under the impression that the reason x86 moved the task_struct from the bottom of the stack to its own slab was that the scheduler had bad cache effects due to all task_structs being on the same 4k boundary. Obviously, ia64 has slightly different caches from x86, but I just wanted to point out that it isn't necessarily all bad to move the task_struct off the stack. -- "Next the statesmen will invent cheap lies, putting the blame upon the nation that is attacked, and every man will be glad of those conscience-soothing falsities, and will diligently study them, and refuse to examine any refutations of them; and thus he will by and by convince himself that the war is just, and will thank God for the better sleep he enjoys after this process of grotesque self-deception." -- Mark Twain