On Fri, Aug 30, 2013 at 6:52 PM, Linus Torvalds <torva...@linux-foundation.org> wrote: > On Fri, Aug 30, 2013 at 9:37 AM, Sedat Dilek <sedat.di...@gmail.com> wrote: >> >> Where is this a.out file from or how to generate it? > > Oh, that's just the silly threaded test-binary. I don't know what you > called it. > > As to your config options, yesh, you have some expensive stuff. > DEBUG_OBJECTS and DEBUG_MUTEXES in particular tend to cause lots of > horrible performance issues. I didn't check if there might be other > things.. >
I tried w/o DEBUG_OBJECTS and DEBUG_MUTEXES and disabled some
unnecessary debug-options, too (see attached diff).
This is what I get now...
[ TEST-CASE ]
$ ~/src/linux-kernel/linux/tools/perf/perf stat --null --repeat 5
./scripts/t_lockref_from-linus
Total loops: 26480075
Total loops: 27002388
Total loops: 25761463
Total loops: 26877615
Total loops: 27047644
Performance counter stats for './scripts/t_lockref_from-linus' (5 runs):
10,008617789 seconds time elapsed
( +- 0,07% )
Looks like this is now 10x faster: ~2.66Mloops (debug) VS.
~26.60Mloops (no-debug).
[ PERF-RECORD ]
$ sudo ~/src/linux-kernel/linux/tools/perf/perf record -e cycles:pp
./scripts/t_lockref_from-linus
Total loops: 26601346
[ perf record: Woken up 25 times to write data ]
[ perf record: Captured and wrote 6.100 MB perf.data (~266501 samples) ]
[ PERF-REPORT ]
$ sudo ~/src/linux-kernel/linux/tools/perf/perf report -f
Samples: 159K of event 'cycles:pp', Event count (approx.): 76968896763
12,79% t_lockref_from- [kernel.kallsyms] [k] irq_return
4,36% t_lockref_from- [kernel.kallsyms] [k] __ticket_spin_lock
4,36% t_lockref_from- [kernel.kallsyms] [k] __acct_update_integrals
4,07% t_lockref_from- [kernel.kallsyms] [k] user_exit
3,12% t_lockref_from- [kernel.kallsyms] [k] local_clock
2,83% t_lockref_from- [kernel.kallsyms] [k] lockref_get_or_lock
2,73% t_lockref_from- [kernel.kallsyms] [k] kmem_cache_alloc
2,62% t_lockref_from- [kernel.kallsyms] [k] __d_lookup_rcu
2,53% t_lockref_from- libc-2.15.so [.] __xstat64
2,53% t_lockref_from- [kernel.kallsyms] [k] kmem_cache_free
2,28% t_lockref_from- [kernel.kallsyms] [k] path_init
2,27% t_lockref_from- [kernel.kallsyms] [k] link_path_walk
1,86% t_lockref_from- [kernel.kallsyms] [k] user_enter
1,85% t_lockref_from- [kernel.kallsyms] [k] rcu_eqs_exit_common.isra.43
1,81% t_lockref_from- [kernel.kallsyms] [k] sched_clock_cpu
1,79% t_lockref_from- [kernel.kallsyms] [k] rcu_eqs_enter_common.isra.45
1,78% t_lockref_from- [kernel.kallsyms] [k] path_lookupat
1,67% t_lockref_from- [kernel.kallsyms] [k] native_read_tsc
1,63% t_lockref_from- [kernel.kallsyms] [k] cp_new_stat
1,61% t_lockref_from- [kernel.kallsyms] [k] lockref_put_or_lock
1,53% t_lockref_from- [kernel.kallsyms] [k] account_system_time
1,48% t_lockref_from- [kernel.kallsyms] [k] tracesys
1,47% t_lockref_from- [kernel.kallsyms] [k] copy_user_generic_unrolled
1,46% t_lockref_from- [kernel.kallsyms] [k] syscall_trace_enter
1,39% t_lockref_from- [kernel.kallsyms] [k] jiffies_to_timeval
1,33% t_lockref_from- [kernel.kallsyms] [k] native_sched_clock
1,27% t_lockref_from- [kernel.kallsyms] [k] getname_flags
1,27% t_lockref_from- [kernel.kallsyms] [k] lookup_fast
1,18% t_lockref_from- [kernel.kallsyms] [k] get_vtime_delta
1,05% t_lockref_from- [kernel.kallsyms] [k] syscall_trace_leave
1,03% t_lockref_from- [kernel.kallsyms] [k] generic_fillattr
1,02% t_lockref_from- [kernel.kallsyms] [k] strncpy_from_user
1,00% t_lockref_from- [kernel.kallsyms] [k] user_path_at_empty
0,97% t_lockref_from- [kernel.kallsyms] [k] account_user_time
0,95% t_lockref_from- [kernel.kallsyms] [k] vfs_fstatat
0,95% t_lockref_from- [kernel.kallsyms] [k] system_call_after_swapgs
0,92% t_lockref_from- [kernel.kallsyms] [k] generic_permission
0,91% t_lockref_from- [kernel.kallsyms] [k] filename_lookup
0,80% t_lockref_from- [kernel.kallsyms] [k] vfs_getattr
0,78% t_lockref_from- [kernel.kallsyms] [k] __ticket_spin_unlock
0,74% t_lockref_from- [kernel.kallsyms] [k] complete_walk
0,70% t_lockref_from- [kernel.kallsyms] [k] vtime_account_user
0,68% t_lockref_from- [kernel.kallsyms] [k] d_rcu_to_refcount
0,65% t_lockref_from- [kernel.kallsyms] [k] common_perm
0,62% t_lockref_from- [kernel.kallsyms] [k] rcu_eqs_enter
0,58% t_lockref_from- [kernel.kallsyms] [k] vtime_user_enter
0,57% t_lockref_from- [kernel.kallsyms] [k] __inode_permission
0,55% t_lockref_from- [kernel.kallsyms] [k] dput
0,52% t_lockref_from- [kernel.kallsyms] [k] apparmor_inode_getattr
0,52% t_lockref_from- [kernel.kallsyms] [k] SYSC_newstat
0,52% t_lockref_from- [kernel.kallsyms] [k] mntget
0,49% t_lockref_from- [kernel.kallsyms] [k] cpuacct_account_field
0,48% t_lockref_from- [kernel.kallsyms] [k] __vtime_account_system
0,46% t_lockref_from- t_lockref_from-linus [.] start_routine
Thanks for all the explanations and hints.
Regards,
- Sedat -
P.S.: Some words to "perf -f"...
$ sudo ~/src/linux-kernel/linux/tools/perf/perf record -f -e cycles:pp
./scripts/t_lockref_from-linus
[sudo] password for wearefam:
Error: unknown switch `f'
usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list
available events
--filter <filter>
event filter
-p, --pid <pid> record events on existing process id
-t, --tid <tid> record events on existing thread id
-r, --realtime <n> collect data with this RT SCHED_FIFO priority
-D, --no-delay collect data without buffering
-R, --raw-samples collect raw sample records from all opened counters
-a, --all-cpus system-wide collection from all CPUs
-C, --cpu <cpu> list of cpus to monitor
-c, --count <n> event period to sample
-o, --output <file> output file name
-i, --no-inherit child tasks do not inherit counters
-F, --freq <n> profile at this frequency
-m, --mmap-pages <n> number of mmap data pages
--group put the counters into a counter group
-g, --call-graph <mode[,dump_size]>
do call-graph (stack chain/backtrace)
recording: [fp] dwarf
-v, --verbose be more verbose (show counter open errors, etc)
-q, --quiet don't print any message
-s, --stat per thread counts
-d, --data Sample addresses
-T, --timestamp Sample timestamps
-P, --period Sample period
-n, --no-samples don't sample
-N, --no-buildid-cache
do not update the buildid cache
-B, --no-buildid do not collect buildids in perf.data
-G, --cgroup <name> monitor event in cgroup name only
-u, --uid <user> user to profile
-b, --branch-any sample any taken branches
-j, --branch-filter <branch filter mask>
branch stack filter modes
-W, --weight sample by weight (on special events only)
- EOT -
kernel-config.diff
Description: Binary data
