Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760298AbYBOV4t (ORCPT ); Fri, 15 Feb 2008 16:56:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759640AbYBOV4a (ORCPT ); Fri, 15 Feb 2008 16:56:30 -0500 Received: from fg-out-1718.google.com ([72.14.220.158]:41743 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759547AbYBOV42 (ORCPT ); Fri, 15 Feb 2008 16:56:28 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject:content-type:content-transfer-encoding; b=Do1XxQ3MvfxsDy8PaGICDH/5bg0ptNAz8u4vdzEo90AQcQSYJPRydkCNdJR8V0WzaAYjSkkLgm9BQayfJKhQkZXl6bQdrpAWP6mESq7OmUGuXLLBSiMPtswyRnlTYhuw+TRDeGwt7D8QAQUh5JLgSP2qzydVx04fo0Nr1wvwy1s= Message-ID: <47B60A87.8000605@gmail.com> Date: Fri, 15 Feb 2008 23:56:23 +0200 From: =?ISO-8859-1?Q?T=F6r=F6k_Edwin?= User-Agent: Mozilla-Thunderbird 2.0.0.9 (X11/20080109) MIME-Version: 1.0 To: Arjan van de Ven CC: Linux Kernel Subject: LatencyTOP: sync_page description Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2717 Lines: 57 Hi Arjan, LatencyTOP says that sync_page is 'Writing a page to disk', however I see that even when no writes are involved, such as during a readdir, lseek, etc. Naming it a write is misleading, as no program is running that is doing constant writes to the disk. The only program is writing to a temp dir in /dev/shm. What would be a better description for sync_page? Here are some /proc/latency_stats containing sync_page: 125 6937678 210821 sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read get_unused_fd_flags path_walk do_sync_read autoremove_wake_function security_file_permission rw_verify_area 306 5677749 215746 sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read do_sync_read autoremove_wake_function security_file_permission rw_verify_area vfs_read vfs_llseek 21 435657 59966 sync_page sync_page __lock_page wake_bit_function read_cache_page_async ntfs_readpage read_cache_page map_mft_record ntfs_read_locked_inode ntfs_alloc_big_inode iget5_locked ntfs_test_inode 195 2716409 133660 blk_unplug sync_page sync_page __lock_page wake_bit_function read_cache_page_async ntfs_readpage read_cache_page map_mft_record ntfs_read_locked_inode ntfs_alloc_big_inode iget5_locked 28 1881278 181986 add_to_page_cache_lru sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read get_unused_fd_flags path_walk do_sync_read autoremove_wake_function security_file_permission 2 17132 9746 add_to_page_cache_lru sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read do_sync_read autoremove_wake_function security_file_permission rw_verify_area vfs_read 1 70 70 irq_exit sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read do_sync_read autoremove_wake_function security_file_permission rw_verify_area vfs_read 23 306682 114514 blk_unplug sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read do_sync_read autoremove_wake_function security_file_permission rw_verify_area vfs_read 1 153 153 hrtimer_interrupt smp_apic_timer_interrupt sync_page sync_page_killable sync_page_killable __lock_page_killable wake_bit_function generic_file_aio_read do_sync_read autoremove_wake_function cfq_idle_slice_timer security_file_permission Thanks, --Edwin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/