[rcu] 878d7439d0: -100% softirqs.RCU

From: Fengguang Wu
Date: Mon Jan 20 2014 - 04:31:03 EST


Hi Eric,

Just FYI, we noticed the below changes in old commit 878d7439d0 ("rcu:
Fix batch-limit size problem") in test case will-it-scale/open1:

62da1921292ef78 878d7439d0f45a95869e41757
--------------- -------------------------
0.00 ~200% +60900.0% 1.22 ~18% TOTAL perf-profile.cpu-clock.file_free_rcu.rcu_process_callbacks.__do_softirq.call_softirq.do_softirq
0.28 ~126% +339.3% 1.23 TOTAL perf-profile.cpu-clock.__d_lookup_rcu.link_path_walk.do_filp_open.do_sys_open.sys_open
1.16 ~15% -100.0% 0.00 TOTAL perf-profile.cpu-clock.file_free_rcu.rcu_process_callbacks.__do_softirq.run_ksoftirqd.smpboot_thread_fn
1.89e+08 ~14% -100.0% 63093 ~ 6% TOTAL softirqs.RCU
3.66 ~ 7% -100.0% 0.00 TOTAL perf-profile.cpu-clock.rcu_process_callbacks.__do_softirq.run_ksoftirqd.smpboot_thread_fn.kthread
1.29 ~11% -100.0% 0.00 TOTAL perf-profile.cpu-clock.rcu_process_gp_end.isra.23.rcu_process_callbacks.__do_softirq.run_ksoftirqd.smpboot_thread_fn
1.39 ~ 9% -100.0% 0.00 TOTAL perf-profile.cpu-clock.check_for_new_grace_period.isra.25.rcu_process_callbacks.__do_softirq.run_ksoftirqd.smpboot_thread_fn
57276 ~ 9% +110.2% 120367 ~15% TOTAL slabinfo.kmalloc-256.active_objs
3582 ~ 9% +110.0% 7525 ~15% TOTAL slabinfo.kmalloc-256.active_slabs
3582 ~ 9% +110.0% 7525 ~15% TOTAL slabinfo.kmalloc-256.num_slabs
57331 ~ 9% +110.0% 120407 ~15% TOTAL slabinfo.kmalloc-256.num_objs
23741 ~ 6% +71.2% 40652 ~13% TOTAL meminfo.SUnreclaim
19830 ~ 4% -44.1% 11094 ~ 8% TOTAL interrupts.RES
6113 ~ 8% +74.6% 10674 ~12% TOTAL proc-vmstat.nr_slab_unreclaimable
2.44 ~13% +62.9% 3.98 ~13% TOTAL perf-profile.cpu-clock.__slab_alloc.kmem_cache_alloc.get_empty_filp.do_filp_open.do_sys_open
3 ~ 0% -33.3% 2 ~ 0% TOTAL vmstat.procs.r
53183 ~ 3% +31.6% 70006 ~ 8% TOTAL meminfo.Slab
1001 ~ 9% -14.3% 858 ~10% TOTAL slabinfo.kmalloc-128.num_objs
1001 ~ 9% -14.3% 858 ~10% TOTAL slabinfo.kmalloc-128.active_objs
2.47 ~ 7% +12.1% 2.76 ~ 6% TOTAL perf-profile.cpu-clock.__call_rcu.call_rcu_sched.__fput.____fput.task_work_run
6686 ~ 5% -95.9% 272 ~ 3% TOTAL time.involuntary_context_switches
109 ~ 1% +21.3% 132 ~ 1% TOTAL time.system_time
55 ~ 0% +19.6% 66 ~ 0% TOTAL time.percent_of_cpu_this_job_got
899 ~ 3% +10.5% 993 ~ 7% TOTAL vmstat.system.cs

time.system_time

140 ++-------------------------------------------------------------------+
| O O O O |
135 ++ |
O O O O O O O O O O O O O O O O O O O O O
130 ++ O O O O O O O O O |
| |
125 ++ |
| |
120 ++ |
| |
115 ++ |
| .*. .*. *.. |
110 *+ .*. .*. .*.*.*. .* *.*.*..*.*.*.* *. .*. + .*. |
| * *.*.*. * * * *.* *.* * |
105 ++-------------------------------------------------------------------+


time.percent_of_cpu_this_job_got

66 O+O-O-O-O--O-O-O-O-O-O-O-O--O-O-O-O-O-O-O-O--O-O-O-O-O-O-O-O--O-O-O-O-O
| |
64 ++ |
| |
| |
62 ++ |
| |
60 ++ |
| |
58 ++ |
| * * |
| + + + + |
56 ++ .*.*. + *.*.*.*.* *..*.*. .*. |
*.*.*.*.*..*.*.*.* *.* *.*.*.* *..*.*.* |
54 ++--------------------------------------------------------------------+


time.involuntary_context_switches

9000 ++------------------------------------------------------------------+
| * |
8000 ++ .*.*. .* * *. .*.*. .* *. + + .*. |
7000 *+* * + + + .. * *.*.*.*.* + + *.* *. *. .*.*. |
| * * * * *.* |
6000 ++ |
5000 ++ |
| |
4000 ++ |
3000 ++ |
| |
2000 ++ |
1000 ++ |
| O O O |
0 O+--O-O---O---O-O--O-O-O-O-O-O-O-O-O-O-O-O-O-O-O-O--O-O-O-O-O-O-O-O-O
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/