From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <43C7C4C7.8050409@cfl.rr.com> Date: Fri, 13 Jan 2006 10:18:31 -0500 From: Phillip Susi MIME-Version: 1.0 Subject: Re: [PATCH/RFC] Shared page tables References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Dave McCracken Cc: Hugh Dickins , Andrew Morton , Linux Kernel , Linux Memory Management List-ID: Shouldn't those kind of applications already be using threads to share page tables rather than forking hundreds of processes that all mmap() the same file? Dave McCracken wrote: > Here's a new version of my shared page tables patch. > > The primary purpose of sharing page tables is improved performance for > large applications that share big memory areas between multiple processes. > It eliminates the redundant page tables and significantly reduces the > number of minor page faults. Tests show significant performance > improvement for large database applications, including those using large > pages. There is no measurable performance degradation for small processes. > > This version of the patch uses Hugh's new locking mechanism, extending it > up the page table tree as far as necessary for proper concurrency control. > > The patch also includes the proper locking for following the vma chains. > > Hugh, I believe I have all the lock points nailed down. I'd appreciate > your input on any I might have missed. > > The architectures supported are i386 and x86_64. I'm working on 64 bit > ppc, but there are still some issues around proper segment handling that > need more testing. This will be available in a separate patch once it's > solid. > > Dave McCracken > -- 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