From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: [LSF/MM TOPIC] THP page cache Date: Thu, 20 Mar 2014 21:43:55 +0200 Message-ID: <20140320194355.GA4896@node.dhcp.inet.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ning Qu , Andi Kleen , Dave Hansen To: lsf-pc@lists.linux-foundation.org Return-path: Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org Hi, I believe we will get to transparent huge pages at summit anyway. Below is data points on file-backed transparent huge pages. The code I have by the time is in my repo[1], see branches thp/pc/v7/p1-base and thp/pc/v7/p2-mmap. Ning Qu works on rebasing shmem/tmpfs support on top of this. Workloads known to benefit from THP for page cache: - MongoDB: mongoperf on ramfs shows increase number of iops by 1.9x for r/o and 1.7x for r/w; - Google search/indexing benchmark shows +3% (in addition to +5% from AnonTHP), on pair with hugetlbfs; - IOZone shows improvement up to 2.5x on ramfs; Should help also with: - Reducing ITLB pressure: + x86-64 binaries is ready to be mapped with 2M pages: binutils creates binaries with required file offset and virtual address alignment, no changes required; + reported 11% performance increase of RDBMS by putting code to hugetlbfs; + MySQL spends 2.5% of cycles in page table walk due ITLB misses[2]; - HPC workloads on many-cores systems (like Xeon Phi): large code and data, small TLB, limited memory bandwidth. [1] git://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git [2] http://research.cs.wisc.edu/multifacet/papers/isca13_direct_segment.pdf -- Kirill A. Shutemov -- 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