Messages in this thread | | | Subject | Re: [PATCH 5/6] perf_counter: add more context information | From | Peter Zijlstra <> | Date | Thu, 02 Apr 2009 20:29:58 +0200 |
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On Thu, 2009-04-02 at 20:18 +0200, Ingo Molnar wrote: > * Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: > > > On Thu, 2009-04-02 at 13:36 +0200, Ingo Molnar wrote: > > > > > > -#define MAX_STACK_DEPTH 255 > > > > +#define MAX_STACK_DEPTH 254 > > > > > > > > struct perf_callchain_entry { > > > > - u64 nr; > > > > + u32 nr, hv, kernel, user; > > > > u64 ip[MAX_STACK_DEPTH]; > > > > }; > > > > Oh, and Paul suggested using u16s right after I send it out. So > > I'll either send an update or send a incremental in case you > > already applied it. > > yes, that's probably a good idea. Although u8 might be even better - > do we ever want to do more than 256 deep stack vectors? Even those > would take quite some time to construct and pass down.
We'd have to pad it with 4 more bytes to remain u64 aligned, also, why restrict ourselves. That MAX_STACK_DEPTH limit is trivially fixable if indeed someone finds its insufficient.
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