From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Kenneth W" Date: Sat, 27 Mar 2004 00:14:13 +0000 Subject: RE: should ia64_spinlock_contention do backoff? Message-Id: <200403270014.i2R0EFF07014@unix-os.sc.intel.com> List-Id: References: <200403251941.i2PJfrTH026392@napali.hpl.hp.com> In-Reply-To: <200403251941.i2PJfrTH026392@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> Chris Wedgwood wrote on Fri, March 26, 2004 3:41 PM > Does anyone have any idea what locks are most heavily contented for > ia64 right now? This question is a bit too broad, lock contention highly depends on workload. For example, I'm doing direct I/O on bunch of block devices, and the dev nodes sit on reiserfs, this contention shows up: 79.7% 91.2% 18us(1415us) 449us( 760ms)(57.9%) 2970234 8.8% 91.2% 0% kernel_flag 0.00% 92.3% 5.8us( 35us) 689us( 58ms)(0.01%) 298 7.7% 92.3% 0% __break_lease+0x80 0.01% 94.3% 23us( 120us) 555us(9106us)(0.01%) 298 5.7% 94.3% 0% chrdev_open+0x1a0 0.00% 83.3% 7.6us( 14us) 73us( 344us)(0.00%) 6 16.7% 83.3% 0% de_put+0x60 0.00% 92.7% 5.4us( 18us) 633us( 14ms)(0.00%) 41 7.3% 92.7% 0% default_llseek+0x60 0.00% 100% 2.9us( 4.2us) 44us( 86us)(0.00%) 2 0% 100% 0% proc_file_lseek+0x60 0.00% 100% 32us( 34us) 2523us(7279us)(0.00%) 3 0% 100% 0% proc_lookup+0x60 0.00% 100% 14us( 17us) 18us( 24us)(0.00%) 2 0% 100% 0% reiserfs_commit_write+0xb0 74.2% 91.2% 16us(1247us) 394us( 292ms)(50.6%) 2959013 8.8% 91.2% 0% reiserfs_dirty_inode+0xa0 0.00% 100% 214us( 214us) 106us( 106us)(0.00%) 1 0% 100% 0% reiserfs_file_release+0x110 0.00% 50.0% 21us( 34us) 29us( 29us)(0.00%) 2 50.0% 50.0% 0% reiserfs_readdir+0xb0 0.01% 92.3% 294us( 369us) 223us(1791us)(0.00%) 13 7.7% 92.3% 0% reiserfs_write_super+0x60 5.5% 92.9% 342us(1415us) 16ms( 760ms)( 7.3%) 10516 7.1% 92.9% 0% schedule+0xe30 0.00% 100% 4.1us( 7.3us) 27us( 45us)(0.00%) 2 0% 100% 0% sys_fcntl+0x430 0.00% 90.9% 14us( 48us) 80us( 254us)(0.00%) 11 9.1% 90.9% 0% sys_ioctl+0xb0 0.00% 93.8% 11us( 21us) 191us(2263us)(0.00%) 16 6.2% 93.8% 0% tty_read+0x170 0.00% 80.0% 17us( 28us) 21us( 38us)(0.00%) 10 20.0% 80.0% 0% tty_write+0x3c0 And if my workload does lots of context switch, load balance also shows up some hot spots. 1.2% 2.1% 1.9us( 22us) 0us 426680 97.9% 0% 2.1% load_balance+0x290 0.02% 89.3% 2.5us( 44us) 3.3us( 635us)(0.00%) 4582 10.7% 89.3% 0% load_balance+0x2d0 0.02% 1.3% 2.9us( 15us) 2.9us( 8.3us)(0.00%) 4582 98.7% 1.3% 0% load_balance+0x2e0 0.01% 84.6% 2.1us( 17us) 2.9us( 21us)(0.00%) 4585 15.4% 84.6% 0% load_balance+0xb60 - Ken