On Fri, 2014-11-21 at 13:04 -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, Nov 21, 2014 at 12:57:06PM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Thu, Nov 20, 2014 at 11:06:05AM -0800, Tuan Bui escreveu: > > > Subject: [PATCH] Perf Bench: Locking Microbenchmark > > > > > > In response to this thread https://lkml.org/lkml/2014/2/11/93, this is > > > a micro benchmark that stresses locking contention in the kernel with > > > creat(2) system call by spawning multiple processes to spam this system > > > call. This workload generate similar results and contentions in AIM7 > > > fserver workload but can generate outputs within seconds. > > > > > > With the creat system call the contention vary on what locks are used > > > in the particular file system. I have ran this benchmark only on ext4 > > > and xfs file system. > > I noticed that if control+C it it leaves tons of files in the current > directory, can you please add code to make it handle this? I think that > it would also be better to create a temporary directory, etc. >
Thank you for the suggestion Arnaldo. I will implement code to handle control+C using a temp directory. > And please take a look at the edited changelog below, to reflect those > changes on your next attempt to submit this patch, ok? I added an > Example so that people can now at a glance how it changes the existing > output for 'perf bench' and what is the output for 'perf bench locking'. > > - Arnaldo > I will definitely include your edited changelog on my next attempt to submit this patch. Thank you. -Tuan > Subject: [PATCH] perf bench: Locking Microbenchmark > > In response to this thread https://lkml.org/lkml/2014/2/11/93, this is > a micro benchmark that stresses locking contention in the kernel with > creat(2) system call by spawning multiple processes to spam this system > call. This workload generate similar results and contentions in AIM7 > fserver workload but can generate outputs within seconds. > > With the creat system call the contention vary on what locks are used > in the particular file system. I have ran this benchmark only on ext4 > and xfs file system. > > Running the creat workload on ext4 show contention in the mutex lock > that is used by ext4_orphan_add() and ext4_orphan_del() to add or delete > an inode from the list of inodes. At the same time running the creat > workload on xfs show contention in the spinlock that is used by > xsf_log_commit_cil() to commit a transaction to the Committed Item List. > > Here is a comparison of this benchmark with AIM7 running fserver workload > at 500-1000 users along with a perf trace running on ext4 file system. > > Test machine is a 8-sockets 80 cores Westmere system HT-off on v3.17-rc6. > > AIM7 AIM7 perf-bench perf-bench > Users Jobs/min Jobs/min/child Ops/sec Ops/sec/child > 500 119668.25 239.34 104249 208 > 600 126074.90 210.12 106136 176 > 700 128662.42 183.80 106175 151 > 800 119822.05 149.78 106290 132 > 900 106150.25 117.94 105230 116 > 1000 104681.29 104.68 106489 106 > > Perf report for AIM7 fserver: > 14.51% reaim [kernel.kallsyms] [k] osq_lock > 4.98% reaim reaim [.] add_long > 4.98% reaim reaim [.] add_int > 4.31% reaim [kernel.kallsyms] [k] mutex_spin_on_owner > ... > > Perf report of 'perf bench locking vfs' > > 22.37% locking-creat [kernel.kallsyms] [k] osq_lock > 5.77% locking-creat [kernel.kallsyms] [k] mutex_spin_on_owner > 5.31% locking-creat [kernel.kallsyms] [k] _raw_spin_lock > 5.15% locking-creat [jbd2] [k] > jbd2_journal_put_journal_head > ... > > Example: > > [root@zoo ~]# perf bench > Usage: > perf bench [<common options>] <collection> <benchmark> > [<options>] > > # List of all available benchmark collections: > > sched: Scheduler and IPC benchmarks > mem: Memory access benchmarks > numa: NUMA scheduling and MM benchmarks > futex: Futex stressing benchmarks > locking: Kernel locking benchmarks > all: All benchmarks > > [root@zoo ~]# perf bench locking > > # List of available benchmarks for collection 'locking': > > vfs: Benchmark vfs using creat(2) > all: Run all benchmarks in this suite > > [root@zoo ~]# perf bench locking vfs > > 100 processes: throughput = 342506 average opts/sec all processes > 100 processes: throughput = 3425 average opts/sec per process > > 200 processes: throughput = 341309 average opts/sec all processes > 200 processes: throughput = 1706 average opts/sec per process > <SNIP> > > Changes since v1: > - Added -j options to specified jobs per processes. > - Change name of microbenchmark from creat to vfs. > - Change all instances of threads to proccess. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
