Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262562AbVBCQu2 (ORCPT ); Thu, 3 Feb 2005 11:50:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262310AbVBCQu1 (ORCPT ); Thu, 3 Feb 2005 11:50:27 -0500 Received: from netblock-66-218-40-30.dslextreme.com ([66.218.40.30]:7626 "EHLO mail.lowrydigital.com") by vger.kernel.org with ESMTP id S263405AbVBCQtm (ORCPT ); Thu, 3 Feb 2005 11:49:42 -0500 Mime-Version: 1.0 (Apple Message framework v619.2) In-Reply-To: References: Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <1e90ea5b2039243539df074d7bc9a658@lowrydigital.com> Content-Transfer-Encoding: 7bit From: Ian Godin Subject: Re: Drive performance bottleneck Date: Thu, 3 Feb 2005 08:49:42 -0800 To: linux-kernel@vger.kernel.org X-Mailer: Apple Mail (2.619.2) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2085 Lines: 67 On Feb 2, 2005, at 7:56 PM, Bernd Eckenfels wrote: > In article you > wrote: >> Below is an oprofile (truncated) of (the same) dd running on >> /dev/sdb. > > do you also have the oprofile of the sg_dd handy? > > Greetings > Bernd > Just ran it on the sg_dd (using /dev/sg1): CPU: P4 / Xeon, speed 3402.13 MHz (estimated) Counted GLOBAL_POWER_EVENTS events (time during which processor is not stopped) with a unit mask of 0x01 (mandatory) count 10 0000 samples % symbol name 2145136 89.7474 __copy_to_user_ll 64720 2.7077 lock_kernel 17883 0.7482 mark_offset_tsc 16212 0.6783 page_address 8091 0.3385 schedule 5380 0.2251 timer_interrupt 5314 0.2223 _spin_lock 5311 0.2222 mwait_idle 4034 0.1688 sysenter_past_esp 3569 0.1493 do_anonymous_page 3530 0.1477 apic_timer_interrupt 3368 0.1409 _spin_lock_irqsave 3150 0.1318 sg_read_xfer 3043 0.1273 kmem_cache_alloc 2590 0.1084 find_busiest_group 2553 0.1068 scheduler_tick 2319 0.0970 __copy_from_user_ll 2299 0.0962 sg_ioctl 2131 0.0892 irq_entries_start 1905 0.0797 sys_ioctl 1773 0.0742 copy_page_range 1678 0.0702 fget 1648 0.0689 __switch_to 1648 0.0689 scsi_block_when_processing_errors 1632 0.0683 sg_start_req 1569 0.0656 increment_tail 1511 0.0632 try_to_wake_up 1506 0.0630 update_one_process 1454 0.0608 fput 1397 0.0584 do_gettimeofday 1396 0.0584 zap_pte_range 1371 0.0574 recalc_task_prio 1357 0.0568 sched_clock 1352 0.0566 sg_link_reserve 1282 0.0536 __elv_add_request 1229 0.0514 kmap_atomic 1195 0.0500 page_fault Oddly enough it appears to also be copying to user space... Ian. - 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/