| Message ID | 1389309492-31174-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 03dbc77..35d7565 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -720,7 +720,7 @@ static int ftrace_profile_init(void) int cpu; int ret = 0; - for_each_online_cpu(cpu) { + for_each_possible_cpu(cpu) { ret = ftrace_profile_init_cpu(cpu); if (ret) break;
This is a note to let you know that I have just added a patch titled ftrace: Initialize the ftrace profiler for each possible cpu to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.16. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From dcb9ad194c5f5a6ff0b5cc6b1e46194770d9bffc Mon Sep 17 00:00:00 2001 From: Miao Xie <miaox@cn.fujitsu.com> Date: Mon, 16 Dec 2013 15:20:01 +0800 Subject: ftrace: Initialize the ftrace profiler for each possible cpu commit c4602c1c818bd6626178d6d3fcc152d9f2f48ac0 upstream. Ftrace currently initializes only the online CPUs. This implementation has two problems: - If we online a CPU after we enable the function profile, and then run the test, we will lose the trace information on that CPU. Steps to reproduce: # echo 0 > /sys/devices/system/cpu/cpu1/online # cd <debugfs>/tracing/ # echo <some function name> >> set_ftrace_filter # echo 1 > function_profile_enabled # echo 1 > /sys/devices/system/cpu/cpu1/online # run test - If we offline a CPU before we enable the function profile, we will not clear the trace information when we enable the function profile. It will trouble the users. Steps to reproduce: # cd <debugfs>/tracing/ # echo <some function name> >> set_ftrace_filter # echo 1 > function_profile_enabled # run test # cat trace_stat/function* # echo 0 > /sys/devices/system/cpu/cpu1/online # echo 0 > function_profile_enabled # echo 1 > function_profile_enabled # cat trace_stat/function* # run test # cat trace_stat/function* So it is better that we initialize the ftrace profiler for each possible cpu every time we enable the function profile instead of just the online ones. Link: http://lkml.kernel.org/r/1387178401-10619-1-git-send-email-miaox@cn.fujitsu.com Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- kernel/trace/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.8.3.2