On Sun, Jun 30, 2013 at 09:57:36AM +0200, Mike Galbraith wrote: > taskset -c 3 pipe-test 1 > > switch-rate > 3.10.0-master 426.4 KHz > 3.10.0-masterx 591.8 Khz 1.387 (591=notgood, 426=omfg) > > 3.10.0-master 3.10.0-masterx > 7.13% [k] __schedule 9.58% [k] __schedule > ! 6.02% [.] __read_nocancel 8.25% [k] system_call > ! 5.82% [.] __write_nocancel 5.34% [k] > _raw_spin_lock_irqsave > ! 4.28% [k] system_call 4.26% [k] pipe_read > ! 4.13% [k] user_exit 3.53% [k] > copy_user_generic_string > 3.64% [k] _raw_spin_lock_irqsave 3.52% [k] > native_sched_clock > 3.37% [k] pipe_read 3.43% [k] __switch_to > 2.72% [k] copy_user_generic_string 3.21% [.] main > 2.60% [.] main 2.96% [k] mutex_lock > 2.59% [k] native_sched_clock 2.89% [k] mutex_unlock > 2.47% [k] __switch_to 2.86% [k] > sched_clock_local > 2.10% [k] mutex_unlock 2.63% [.] > __read_nocancel > 2.08% [k] sched_clock_local 2.47% [k] pipe_write > 2.05% [k] mutex_lock 2.37% [k] > _raw_spin_unlock_irqrestore > 1.91% [k] pipe_write 1.96% [.] > __write_nocancel > 1.89% [k] user_enter 1.62% [k] vfs_write > 1.72% [k] _raw_spin_unlock_irqrestore 1.54% [k] do_sync_write > 1.51% [k] rcu_eqs_enter_common.isra.47 1.52% [k] fget_light > 1.41% [k] rcu_eqs_exit_common.isra.45 1.48% [k] fsnotify > 1.30% [k] tracesys 1.39% [k] > dequeue_task_fair > 1.23% [k] fsnotify 1.39% [k] update_curr > 1.23% [k] int_check_syscall_exit_worka 1.37% [k] do_sync_read > 1.20% [k] fget_light 1.33% [.] > __GI___libc_write > 1.16% [k] vfs_write 1.29% [k] > try_to_wake_up > 1.05% [k] syscall_trace_enter 1.09% [k] > _raw_spin_lock_irq > 1.04% [k] do_sync_write 1.08% [k] > pipe_iov_copy_from_user > 1.03% [k] context_tracking_task_switch 1.05% [k] > finish_task_switch > 0.99% [k] update_curr 1.04% [k] > prepare_to_wait >
Yeah, who'd have thought that putting stuff in the syscall path would've made syscalls more expensive ;-) But yeah, that's a _lot_ more expensive.. I'd not be surprised if more people would find that objectionable. -- 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/
