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| author | Changbin Du <changbin.du@intel.com> | 2017-11-30 11:39:43 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-20 10:04:51 +0100 |
| commit | a34419b3f6a277b4da240f7b7a5e8be4d5c2356b (patch) | |
| tree | 6bf363aaf00f7b4ba59ae69008757f076b4fae02 /tools/perf/scripts/python/bin | |
| parent | c60db4f68593e381571fdf9e2111363e1793cdf4 (diff) | |
tracing: Allocate mask_str buffer dynamically
commit 90e406f96f630c07d631a021fd4af10aac913e77 upstream.
The default NR_CPUS can be very large, but actual possible nr_cpu_ids
usually is very small. For my x86 distribution, the NR_CPUS is 8192 and
nr_cpu_ids is 4. About 2 pages are wasted.
Most machines don't have so many CPUs, so define a array with NR_CPUS
just wastes memory. So let's allocate the buffer dynamically when need.
With this change, the mutext tracing_cpumask_update_lock also can be
removed now, which was used to protect mask_str.
Link: http://lkml.kernel.org/r/1512013183-19107-1-git-send-email-changbin.du@intel.com
Fixes: 36dfe9252bd4c ("ftrace: make use of tracing_cpumask")
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/scripts/python/bin')
0 files changed, 0 insertions, 0 deletions