Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757509AbZAVLbn (ORCPT ); Thu, 22 Jan 2009 06:31:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754762AbZAVLbc (ORCPT ); Thu, 22 Jan 2009 06:31:32 -0500 Received: from brick.kernel.dk ([93.163.65.50]:2823 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751725AbZAVLba (ORCPT ); Thu, 22 Jan 2009 06:31:30 -0500 Date: Thu, 22 Jan 2009 12:29:55 +0100 From: Jens Axboe To: "Chilukuri, Harita" Cc: Matthew Wilcox , Andi Kleen , Andrew Morton , "Wilcox, Matthew R" , "Ma, Chinang" , "linux-kernel@vger.kernel.org" , "Tripathi, Sharad C" , "arjan@linux.intel.com" , "Siddha, Suresh B" , "Styner, Douglas W" , "Wang, Peter Xihong" , "Nueckel, Hubert" , "chris.mason@oracle.com" , "srostedt@redhat.com" , "linux-scsi@vger.kernel.org" , Andrew Vasquez , Anirban Chakraborty Subject: Re: Mainline kernel OLTP performance update Message-ID: <20090122112955.GH30821@kernel.dk> References: <20090114163557.11e097f2.akpm@linux-foundation.org> <20090115012147.GW29283@parisc-linux.org> <20090114180431.f4a96543.akpm@linux-foundation.org> <874p01fg3a.fsf@basil.nowhere.org> <20090115024740.GX29283@parisc-linux.org> <20090120132703.GJ30821@kernel.dk> <588992150B702C48B3312184F1B810AD03A497632C@azsmsx501.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <588992150B702C48B3312184F1B810AD03A497632C@azsmsx501.amr.corp.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5774 Lines: 154 On Wed, Jan 21 2009, Chilukuri, Harita wrote: > Jen, we work with Matthew on the OLTP workload and have tested the part_stats patch on 2.6.29-rc2. Below are the details: > > Disabling the part_stats has positive impact on the OLTP workload. > > Linux OLTP Performance summary > Kernel# Speedup(x) Intr/s CtxSw/s us% sys% idle% iowait% > 2.6.29-rc2-part_stats 1.000 30329 41716 74 26 0 0 > 2.6.29-rc2-disable-part_stats 1.006 30413 42582 74 25 0 0 > > Server configurations: > Intel Xeon Quad-core 2.0GHz 2 cpus/8 cores/8 threads > 64GB memory, 3 qle2462 FC HBA, 450 spindles (30 logical units) > > > ======oprofile CPU_CLK_UNHALTED for top 30 functions > Cycles% 2.6.29-rc2-part_stats Cycles% 2.6.29-rc2-disable-part_stats > 0.9634 qla24xx_intr_handler 1.0372 qla24xx_intr_handler > 0.9057 copy_user_generic_string 0.7461 qla24xx_wrt_req_reg > 0.7583 unmap_vmas 0.7130 kmem_cache_alloc > 0.6280 qla24xx_wrt_req_reg 0.6876 copy_user_generic_string > 0.6088 kmem_cache_alloc 0.5656 qla24xx_start_scsi > 0.5468 clear_page_c 0.4881 __blockdev_direct_IO > 0.5191 qla24xx_start_scsi 0.4728 try_to_wake_up > 0.4892 try_to_wake_up 0.4588 unmap_vmas > 0.4870 __blockdev_direct_IO 0.4360 scsi_request_fn > 0.4187 scsi_request_fn 0.3711 __switch_to > 0.3717 __switch_to 0.3699 aio_complete > 0.3567 rb_get_reader_page 0.3648 rb_get_reader_page > 0.3396 aio_complete 0.3597 ring_buffer_consume > 0.3012 __end_that_request_first 0.3292 memset_c > 0.2926 memset_c 0.3076 __list_add > 0.2926 ring_buffer_consume 0.2771 clear_page_c > 0.2884 page_remove_rmap 0.2745 task_rq_lock > 0.2691 disk_map_sector_rcu 0.2733 generic_make_request > 0.2670 copy_page_c 0.2555 tcp_sendmsg > 0.2670 lock_timer_base 0.2529 qla2x00_process_completed_re > 0.2606 qla2x00_process_completed_re0.2440 e1000_xmit_frame > 0.2521 task_rq_lock 0.2390 lock_timer_base > 0.2328 __list_add 0.2364 qla24xx_queuecommand > 0.2286 generic_make_request 0.2301 kmem_cache_free > 0.2286 pick_next_highest_task_rt 0.2262 blk_queue_end_tag > 0.2136 push_rt_task 0.2262 kref_get > 0.2115 blk_queue_end_tag 0.2250 push_rt_task > 0.2115 kmem_cache_free 0.2135 scsi_dispatch_cmd > 0.2051 e1000_xmit_frame 0.2084 sd_prep_fn > 0.2051 scsi_device_unbusy 0.2059 kfree Alright, so that 0.6%. IIRC, 0.1% (or there abouts) is significant with this benchmark, correct? To get a feel for the rest of the accounting overhead, could you try with this patch that just disables the whole thing? diff --git a/block/blk-core.c b/block/blk-core.c index a824e49..eec9126 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -64,6 +64,7 @@ static struct workqueue_struct *kblockd_workqueue; static void drive_stat_acct(struct request *rq, int new_io) { +#if 0 struct hd_struct *part; int rw = rq_data_dir(rq); int cpu; @@ -82,6 +83,7 @@ static void drive_stat_acct(struct request *rq, int new_io) } part_stat_unlock(); +#endif } void blk_queue_congestion_threshold(struct request_queue *q) @@ -1014,6 +1017,7 @@ static inline void add_request(struct request_queue *q, struct request *req) __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0); } +#if 0 static void part_round_stats_single(int cpu, struct hd_struct *part, unsigned long now) { @@ -1027,6 +1031,7 @@ static void part_round_stats_single(int cpu, struct hd_struct *part, } part->stamp = now; } +#endif /** * part_round_stats() - Round off the performance stats on a struct disk_stats. @@ -1046,11 +1051,13 @@ static void part_round_stats_single(int cpu, struct hd_struct *part, */ void part_round_stats(int cpu, struct hd_struct *part) { +#if 0 unsigned long now = jiffies; if (part->partno) part_round_stats_single(cpu, &part_to_disk(part)->part0, now); part_round_stats_single(cpu, part, now); +#endif } EXPORT_SYMBOL_GPL(part_round_stats); @@ -1690,6 +1697,7 @@ static int __end_that_request_first(struct request *req, int error, (unsigned long long)req->sector); } +#if 0 if (blk_fs_request(req) && req->rq_disk) { const int rw = rq_data_dir(req); struct hd_struct *part; @@ -1700,6 +1708,7 @@ static int __end_that_request_first(struct request *req, int error, part_stat_add(cpu, part, sectors[rw], nr_bytes >> 9); part_stat_unlock(); } +#endif total_bytes = bio_nbytes = 0; while ((bio = req->bio) != NULL) { @@ -1779,7 +1788,9 @@ static int __end_that_request_first(struct request *req, int error, */ static void end_that_request_last(struct request *req, int error) { +#if 0 struct gendisk *disk = req->rq_disk; +#endif if (blk_rq_tagged(req)) blk_queue_end_tag(req->q, req); @@ -1797,6 +1808,7 @@ static void end_that_request_last(struct request *req, int error) * IO on queueing nor completion. Accounting the containing * request is enough. */ +#if 0 if (disk && blk_fs_request(req) && req != &req->q->bar_rq) { unsigned long duration = jiffies - req->start_time; const int rw = rq_data_dir(req); @@ -1813,6 +1825,7 @@ static void end_that_request_last(struct request *req, int error) part_stat_unlock(); } +#endif if (req->end_io) req->end_io(req, error); -- Jens Axboe -- 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/