1 Commits

Author	SHA1	Message	Date
Arnaldo Carvalho de Melo	0a7c74eae3	perf tools: Provide mutex wrappers for pthreads rwlocks ... Andi reported a performance drop in single threaded perf tools such as 'perf script' due to the growing number of locks being put in place to allow for multithreaded tools, so wrap the POSIX threads rwlock routines with the names used for such kinds of locks in the Linux kernel and then allow for tools to ask for those locks to be used or not. I.e. a tool may have a multithreaded phase and then switch to single threaded, like the upcoming patches for the synthesizing of PERF_RECORD_{FORK,MMAP,etc} for pre-existing processes to then switch to single threaded mode in 'perf top'. The init routines will not be conditional, this way starting as single threaded to then move to multi threaded mode should be possible. Reported-by: Andi Kleen <ak@linux.intel.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20170404161739.GH12903@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>	2017-09-21 13:28:06 -03:00