Messages in this thread | | | Date | Wed, 26 May 2010 15:20:16 +0800 | From | Li Zefan <> | Subject | Re: Tracing configuration review |
| |
Pekka Enberg wrote: > On Tue, May 25, 2010 at 11:13 PM, Frederic Weisbecker > <fweisbec@gmail.com> wrote: >>> # CONFIG_KMEMTRACE is not set (Kconfig says N if unsure) >> Deprecated. We have the kmem trace event that are a full replacement now. >> Pekka, Gabriel, can we remove it now? > > I don't think ftrace supports boot-time tracing which kmemtrace did.
We can do boot-time tracing by passing "trace_event=" kernel parameter.
By passing "ftrace=kmemtrace", kmemtrace can be started when calling tracer_alloc_buffer(), which is an early_initcall. While trace events are inititialized as a fs_initcall, it can be modified to an early_initcall.
Furthermore, I noticed the discussion on perf persistent events, which seems to enable perf trace at boot time, so I think perf-kmem can take advantage of this and will be a full-replacement of kmemtrace soon ?
> That said, I was probably the only one actually using the feature so > maybe we can just nuke kmemtrace at this point...
If you agree on removing kmemtrace now, I'll re-send the patch.
| |