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https://github.com/Fishwaldo/Star64_linux.git
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a7636d9ecf
When doing ebpf+kprobe on some hot TCP functions (e.g. tcp_rcv_established), the kprobe_dispatcher() function shows up in 'perf report'. In kprobe_dispatcher(), there is a lot of cache bouncing on 'tk->nhit++'. 'tk->nhit' and 'tk->tp.flags' also share the same cacheline. perf report (cycles:pp): 8.30% ipv4_dst_check 4.74% copy_user_enhanced_fast_string 3.93% dst_release 2.80% tcp_v4_rcv 2.31% queued_spin_lock_slowpath 2.30% _raw_spin_lock 1.88% mlx4_en_process_rx_cq 1.84% eth_get_headlen 1.81% ip_rcv_finish ~~~~ 1.71% kprobe_dispatcher ~~~~ 1.55% mlx4_en_xmit 1.09% __probe_kernel_read perf report after patch: 9.15% ipv4_dst_check 5.00% copy_user_enhanced_fast_string 4.12% dst_release 2.96% tcp_v4_rcv 2.50% _raw_spin_lock 2.39% queued_spin_lock_slowpath 2.11% eth_get_headlen 2.03% mlx4_en_process_rx_cq 1.69% mlx4_en_xmit 1.19% ip_rcv_finish 1.12% __probe_kernel_read 1.02% ehci_hcd_cleanup Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Kernel Team <kernel-team@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1454531308-2441898-1-git-send-email-kafai@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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| .. | ||
| bpf | ||
| configs | ||
| debug | ||
| events | ||
| gcov | ||
| irq | ||
| livepatch | ||
| locking | ||
| power | ||
| printk | ||
| rcu | ||
| sched | ||
| time | ||
| trace | ||
| .gitignore | ||
| acct.c | ||
| async.c | ||
| audit.c | ||
| audit.h | ||
| audit_fsnotify.c | ||
| audit_tree.c | ||
| audit_watch.c | ||
| auditfilter.c | ||
| auditsc.c | ||
| backtracetest.c | ||
| bounds.c | ||
| capability.c | ||
| cgroup.c | ||
| cgroup_freezer.c | ||
| cgroup_pids.c | ||
| compat.c | ||
| configs.c | ||
| context_tracking.c | ||
| cpu.c | ||
| cpu_pm.c | ||
| cpuset.c | ||
| crash_dump.c | ||
| cred.c | ||
| delayacct.c | ||
| dma.c | ||
| elfcore.c | ||
| exec_domain.c | ||
| exit.c | ||
| extable.c | ||
| fork.c | ||
| freezer.c | ||
| futex.c | ||
| futex_compat.c | ||
| groups.c | ||
| hung_task.c | ||
| irq_work.c | ||
| jump_label.c | ||
| kallsyms.c | ||
| kcmp.c | ||
| Kconfig.freezer | ||
| Kconfig.hz | ||
| Kconfig.locks | ||
| Kconfig.preempt | ||
| kexec.c | ||
| kexec_core.c | ||
| kexec_file.c | ||
| kexec_internal.h | ||
| kmod.c | ||
| kprobes.c | ||
| ksysfs.c | ||
| kthread.c | ||
| latencytop.c | ||
| Makefile | ||
| membarrier.c | ||
| memremap.c | ||
| module-internal.h | ||
| module.c | ||
| module_signing.c | ||
| notifier.c | ||
| nsproxy.c | ||
| padata.c | ||
| panic.c | ||
| params.c | ||
| pid.c | ||
| pid_namespace.c | ||
| profile.c | ||
| ptrace.c | ||
| range.c | ||
| reboot.c | ||
| relay.c | ||
| resource.c | ||
| seccomp.c | ||
| signal.c | ||
| smp.c | ||
| smpboot.c | ||
| smpboot.h | ||
| softirq.c | ||
| stacktrace.c | ||
| stop_machine.c | ||
| sys.c | ||
| sys_ni.c | ||
| sysctl.c | ||
| sysctl_binary.c | ||
| task_work.c | ||
| taskstats.c | ||
| test_kprobes.c | ||
| torture.c | ||
| tracepoint.c | ||
| tsacct.c | ||
| uid16.c | ||
| up.c | ||
| user-return-notifier.c | ||
| user.c | ||
| user_namespace.c | ||
| utsname.c | ||
| utsname_sysctl.c | ||
| watchdog.c | ||
| workqueue.c | ||
| workqueue_internal.h | ||