leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

This fixes a long standing bug in the ftrace profiler.

Browse Source 
The problem is that the profiler only initializes the online
 CPUs, and not possible CPUs. This causes issues if the user takes
 CPUs online or offline while the profiler is running.
 
 If we online a CPU after starting the profiler, we lose all the
 trace information on the CPU going online.
 
 If we offline a CPU after running a test and start a new test, it
 will not clear the old data from that CPU.
 
 This bug causes incorrect data to be reported to the user if they
 online or offline CPUs during the profiling.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.15 (GNU/Linux)
 
 iQEcBAABAgAGBQJSsNBHAAoJEKQekfcNnQGuKP8H/2mol/d7z2vANh7/FeNjTKIN
 VkRzDEwUIwoaJBsL75EDDXBFx7w8jjAsXyoTrqrvMRV4UNcsfm46mohQTPAmK39y
 muqodL1VnVXdKrUmtw/1nL7yDi2KltQH1UwOgvwXGuUFIq5cuCXNQxNK9/1fVVVn
 tIMNz5kEAG3XCwnqP0PgQxWCuA7s+aQR0ijTf4vPf1G3IJujPyG9VhJWcGS3dJTR
 t8TPyatd9D/S+7/r7iZ9hS8nWpaka3qJfhiWqk16SC9LiUXVA8oFOVMoN7n6Co5E
 6r2dNo01WOABlojCxi1t3afUtcV1bUjBnVkiDva5cSc84pQSxe1qRrIpjTmHk00=
 =MSZs
 -----END PGP SIGNATURE-----

Merge tag 'trace-fixes-v3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace fix from Steven Rostedt:
 "This fixes a long standing bug in the ftrace profiler.  The problem is
  that the profiler only initializes the online CPUs, and not possible
  CPUs.  This causes issues if the user takes CPUs online or offline
  while the profiler is running.

  If we online a CPU after starting the profiler, we lose all the trace
  information on the CPU going online.

  If we offline a CPU after running a test and start a new test, it will
  not clear the old data from that CPU.

  This bug causes incorrect data to be reported to the user if they
  online or offline CPUs during the profiling"

* tag 'trace-fixes-v3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Initialize the ftrace profiler for each possible cpu
This commit is contained in:
Linus Torvalds 2013-12-20 09:32:30 -08:00
commit 5263f0a880
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/trace/ftrace.c
View File

@ -775,7 +775,7 @@ 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;