From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f47.google.com (mail-pa0-f47.google.com [209.85.220.47]) by kanga.kvack.org (Postfix) with ESMTP id 5F9336B006E for ; Fri, 28 Feb 2014 17:34:44 -0500 (EST) Received: by mail-pa0-f47.google.com with SMTP id lj1so1347654pab.34 for ; Fri, 28 Feb 2014 14:34:44 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTP id tm9si3481097pab.337.2014.02.28.14.34.41 for ; Fri, 28 Feb 2014 14:34:41 -0800 (PST) Date: Fri, 28 Feb 2014 14:34:40 -0800 From: Andrew Morton Subject: Re: [PATCH 0/1] mm, shmem: map few pages around fault address if they are in page cache Message-Id: <20140228143440.e0ec026baeced2efbb52aa50@linux-foundation.org> In-Reply-To: <1393625931-2858-1-git-send-email-quning@google.com> References: <1393625931-2858-1-git-send-email-quning@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ning Qu Cc: Linus Torvalds , Mel Gorman , Rik van Riel , "Kirill A. Shutemov" , Andi Kleen , Matthew Wilcox , Dave Hansen , Alexander Viro , Dave Chinner , Ning Qu , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Hugh Dickins On Fri, 28 Feb 2014 14:18:50 -0800 Ning Qu wrote: > This is a follow-up patch for "mm: map few pages around fault address if they are in page cache" > > We use the generic filemap_map_pages as ->map_pages in shmem/tmpfs. > Please cc Hugh on shmem/tmpfs things > > ========================================================================= > Below is just some simple experiment numbers from this patch, let me know if > you would like more: > > Tested on Xeon machine with 64GiB of RAM, using the current default fault > order 4. > > Sequential access 8GiB file > Baseline with-patch > 1 thread > minor fault 205 101 Confused. Sequential access of an 8G file should generate 2,000,000 minor faults, not 205. And with FAULT_AROUND_ORDER=4, that should come down to 2,000,000/16 minor faults when using faultaround? > time, seconds 7.94 7.82 > > Random access 8GiB file > Baseline with-patch > 1 thread > minor fault 724 623 > time, seconds 9.75 9.84 > -- 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