From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753430AbdLELBH (ORCPT ); Tue, 5 Dec 2017 06:01:07 -0500 Received: from mail-qt0-f195.google.com ([209.85.216.195]:32837 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125AbdLELBE (ORCPT ); Tue, 5 Dec 2017 06:01:04 -0500 X-Google-Smtp-Source: AGs4zMZ1aMHi6cOQczMbBvtbZbH510KQk2YUch1KNGBmDiZTIKkkO736S50XNscgTPTucQVXYQVy3Q== Message-ID: <1512471662.4125.2.camel@redhat.com> Subject: Re: [LKP] [lkp-robot] [fs/locks] 52306e882f: stress-ng.lockofd.ops_per_sec -11% regression From: Jeff Layton To: Aaron Lu , Benjamin Coddington Cc: lkp@01.org, Linus Torvalds , LKML , xiaolong.ye@intel.com Date: Tue, 05 Dec 2017 06:01:02 -0500 In-Reply-To: <20171205055746.GA13514@intel.com> References: <20170928080223.GX17200@yexl-desktop> <20171108072233.GA3816@intel.com> <20171205055746.GA13514@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.2 (3.26.2-1.fc27) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2017-12-05 at 13:57 +0800, Aaron Lu wrote: > On Wed, Nov 08, 2017 at 03:22:33PM +0800, Aaron Lu wrote: > > On Thu, Sep 28, 2017 at 04:02:23PM +0800, kernel test robot wrote: > > > > > > Greeting, > > > > > > FYI, we noticed a -11% regression of stress-ng.lockofd.ops_per_sec due to commit: > > > > > > > > > commit: 52306e882f77d3fd73f91435c41373d634acc5d2 ("fs/locks: Use allocation rather than the stack in fcntl_getlk()") > > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > > > It's been a while, I wonder what do you think of this regression? > > > > The test stresses byte-range locks AFAICS and since the commit uses > > dynamic allocation instead of stack for the 'struct file_lock', it sounds > > natural the performance regressed for this test. > > > > Now the question is, do we care about the performance regression here? > > Appreciated it if you can share your opinion on this, thanks. > > Regards, > Aaron > Sorry I missed your earlier mail about this. My feeling is to not worry about it. struct file_lock is rather large, so putting it on the stack was always a bit dangerous, and F_GETLK is a rather uncommon operation anyway. That said, if there are real-world workloads that have regressed because of this patch, I'm definitely open to backing it out. Does anyone else have opinions on the matter? > > Feel free to let me know if you need any other data. > > > > Thanks for your time. > > > > > in testcase: stress-ng > > > on test machine: 88 threads Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz with 128G memory > > > with following parameters: > > > > > > testtime: 1s > > > class: filesystem > > > cpufreq_governor: performance > > > > > > > > > > > > > > > Details are as below: > > > --------------------------------------------------------------------------------------------------> > > > > > > > > > To reproduce: > > > > > > git clone https://github.com/intel/lkp-tests.git > > > cd lkp-tests > > > bin/lkp install job.yaml # job file is attached in this email > > > bin/lkp run job.yaml > > > > > > testcase/path_params/tbox_group/run: stress-ng/1s-filesystem-performance/lkp-bdw-ep6 > > > > > > v4.13-rc1 52306e882f77d3fd73f91435c4 > > > ---------------- -------------------------- > > > %stddev change %stddev > > > \ | \ > > > 1.219e+08 -11% 1.09e+08 stress-ng.lockofd.ops_per_sec > > > 1.229e+08 -10% 1.103e+08 stress-ng.locka.ops_per_sec > > > 1.233e+08 -10% 1.105e+08 stress-ng.locka.ops > > > 1.223e+08 -11% 1.093e+08 stress-ng.lockofd.ops > > > 1061237 10% 1168476 stress-ng.eventfd.ops > > > 1061205 10% 1168414 stress-ng.eventfd.ops_per_sec > > > 2913174 9% 3163165 stress-ng.time.voluntary_context_switches > > > 89.90 -4% 86.58 stress-ng.time.user_time > > > 26510 -6% 24822 stress-ng.io.ops > > > 26489 -6% 24798 stress-ng.io.ops_per_sec > > > 885499 ± 14% 18% 1042236 perf-stat.cpu-migrations > > > 2.537e+08 10% 2.783e+08 perf-stat.node-store-misses > > > 1067830 ± 4% 8% 1154877 ± 3% perf-stat.page-faults > > > 5384755 ± 4% 7% 5747689 perf-stat.context-switches > > > 32.28 7% 34.42 ± 3% perf-stat.node-store-miss-rate% > > > 12245 ±110% -7e+03 5367 ± 29% latency_stats.avg.call_usermodehelper_exec.__request_module.get_fs_type.do_mount.SyS_mount.entry_SYSCALL_64_fastpath > > > 311261 ±173% -3e+05 11702 ±100% latency_stats.avg.tty_release_struct.tty_release.__fput.____fput.task_work_run.exit_to_usermode_loop.syscall_return_slowpath.entry_SYSCALL_64_fastpath > > > 1472 ± 60% 4e+03 5144 ± 97% latency_stats.max.sync_inodes_sb.sync_inodes_one_sb.iterate_supers.sys_sync.entry_SYSCALL_64_fastpath > > > 225 ± 39% 3e+03 3698 ±132% latency_stats.max.rpc_wait_bit_killable.__rpc_wait_for_completion_task.nfs4_do_close.[nfsv4].__nfs4_close.[nfsv4].nfs4_close_sync.[nfsv4].nfs4_close_context.[nfsv4].__put_nfs_open_context.nfs_file_clear_open_context.nfs_file_release.__fput.____fput.task_work_run > > > 228 ± 34% 3e+03 3103 ±159% latency_stats.max.rpc_wait_bit_killable.__rpc_wait_for_completion_task.nfs4_run_open_task.[nfsv4].nfs4_do_open.[nfsv4].nfs4_atomic_open.[nfsv4].nfs4_file_open.[nfsv4].do_dentry_open.vfs_open.path_openat.do_filp_open.do_sys_open.SyS_open > > > 270 ± 24% 3e+03 3110 ±162% latency_stats.max.io_schedule.wait_on_page_bit_common.__filemap_fdatawait_range.filemap_write_and_wait_range.nfs_file_fsync.vfs_fsync_range.vfs_fsync.nfs4_file_flush.[nfsv4].filp_close.do_dup2.SyS_dup2.entry_SYSCALL_64_fastpath > > > 12245 ±110% -7e+03 5367 ± 29% latency_stats.max.call_usermodehelper_exec.__request_module.get_fs_type.do_mount.SyS_mount.entry_SYSCALL_64_fastpath > > > 927506 ±173% -9e+05 11702 ±100% latency_stats.max.tty_release_struct.tty_release.__fput.____fput.task_work_run.exit_to_usermode_loop.syscall_return_slowpath.entry_SYSCALL_64_fastpath > > > 7892 ± 54% 3e+04 33793 ±131% latency_stats.sum.sync_inodes_sb.sync_inodes_one_sb.iterate_supers.sys_sync.entry_SYSCALL_64_fastpath > > > 12030 ±109% 2e+04 33536 ±136% latency_stats.sum.autofs4_wait.autofs4_mount_wait.autofs4_d_manage.follow_managed.lookup_fast.path_openat.do_filp_open.do_sys_open.SyS_open.entry_SYSCALL_64_fastpath > > > 14311 ± 15% 7e+03 21729 ±116% latency_stats.sum.call_rwsem_down_read_failed.page_lock_anon_vma_read.rmap_walk_anon.rmap_walk.try_to_unmap.migrate_pages.migrate_misplaced_page.__handle_mm_fault.handle_mm_fault.__do_page_fault.do_page_fault.page_fault > > > 8095 ± 22% 7e+03 15421 ± 79% latency_stats.sum.call_rwsem_down_read_failed.rmap_walk_anon.rmap_walk.remove_migration_ptes.migrate_pages.migrate_misplaced_page.__handle_mm_fault.handle_mm_fault.__do_page_fault.do_page_fault.page_fault > > > 495 ± 39% 7e+03 7470 ±131% latency_stats.sum.rpc_wait_bit_killable.__rpc_wait_for_completion_task.nfs4_do_close.[nfsv4].__nfs4_close.[nfsv4].nfs4_close_sync.[nfsv4].nfs4_close_context.[nfsv4].__put_nfs_open_context.nfs_file_clear_open_context.nfs_file_release.__fput.____fput.task_work_run > > > 3449 ± 18% 7e+03 10001 ± 68% latency_stats.sum.io_schedule.wait_on_page_bit_common.__filemap_fdatawait_range.filemap_fdatawait_keep_errors.sync_inodes_sb.sync_inodes_one_sb.iterate_supers.sys_sync.entry_SYSCALL_64_fastpath > > > 378 ±123% 6e+03 6438 ±109% latency_stats.sum.io_schedule.__lock_page.find_lock_entry.shmem_getpage_gfp.shmem_fault.__do_fault.__handle_mm_fault.handle_mm_fault.__do_page_fault.do_page_fault.page_fault > > > 386 ± 34% 3e+03 3242 ±153% latency_stats.sum.rpc_wait_bit_killable.__rpc_wait_for_completion_task.nfs4_run_open_task.[nfsv4].nfs4_do_open.[nfsv4].nfs4_atomic_open.[nfsv4].nfs4_file_open.[nfsv4].do_dentry_open.vfs_open.path_openat.do_filp_open.do_sys_open.SyS_open > > > 413 ± 19% 3e+03 3256 ±156% latency_stats.sum.io_schedule.wait_on_page_bit_common.__filemap_fdatawait_range.filemap_write_and_wait_range.nfs_file_fsync.vfs_fsync_range.vfs_fsync.nfs4_file_flush.[nfsv4].filp_close.do_dup2.SyS_dup2.entry_SYSCALL_64_fastpath > > > 2874 ±173% -3e+03 0 latency_stats.sum.call_rwsem_down_write_failed.do_unlinkat.SyS_unlink.entry_SYSCALL_64_fastpath > > > 3683 ±172% -4e+03 5 ±100% latency_stats.sum.call_rwsem_down_read_failed.lookup_slow.walk_component.path_lookupat.filename_lookup.user_path_at_empty.SyS_chmod.entry_SYSCALL_64_fastpath > > > 12245 ±110% -7e+03 5367 ± 29% latency_stats.sum.call_usermodehelper_exec.__request_module.get_fs_type.do_mount.SyS_mount.entry_SYSCALL_64_fastpath > > > 7320 ±136% -7e+03 0 latency_stats.sum.call_rwsem_down_write_failed.do_truncate.do_sys_ftruncate.SyS_ftruncate.entry_SYSCALL_64_fastpath > > > 52297 ±124% -3e+04 26320 ± 16% latency_stats.sum.call_rwsem_down_read_failed.lookup_slow.walk_component.link_path_walk.path_parentat.filename_parentat.do_unlinkat.SyS_unlink.entry_SYSCALL_64_fastpath > > > 64452 ± 83% -3e+04 31383 ± 30% latency_stats.sum.call_rwsem_down_write_failed.do_rmdir.SyS_rmdir.entry_SYSCALL_64_fastpath > > > 1867567 ±173% -2e+06 11702 ±100% latency_stats.sum.tty_release_struct.tty_release.__fput.____fput.task_work_run.exit_to_usermode_loop.syscall_return_slowpath.entry_SYSCALL_64_fastpath > > > > > > > > > > > > > > > Disclaimer: > > > Results have been estimated based on internal Intel analysis and are provided > > > for informational purposes only. Any difference in system hardware or software > > > design or configuration may affect actual performance. > > > > > > > > > Thanks, > > > Xiaolong -- Jeff Layton