Re: 答复: oprofile-list Digest, Vol 108, Issue 1
William Cohen <[email protected]>
| Newsgroups | gmane.linux.oprofile,gmane.comp.emulators.xen.devel |
|---|---|
| Message-ID | <[email protected]> |
On 05/05/2015 12:44 AM, 蒋雄伟(蒋冲) wrote: > In /xen/arch/x86/oprofile/op_counter.h there is a definition > > #define OP_MAX_COUNTER 8 > > As far as I know , the number of counter equals the number of events. As > all we know that the number of events is more than 8. > So my question is : Is it the maximum concurrent counter or the total > counter ? > Hi, You are referring to OP_MAX_COUNTER in: http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/oprofile/op_counter.h;h=b515ac9ebc8e379a36917e6f270653d412a87dd7;hb=refs/heads/master This is the maximum number of performance monitoring counters that the processors could have and can use concurrently. However, some x86 processors have fewer performance counters available. Many AMD processors only have 4 and when hyperthreading is used on some Intel processors the number of counters is halfed with each thread getting 4. The following checks with OP_MAX_COUNTER look a bit odd as a result allowing writing to things that will never be used: http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/oprofile/xenoprof.c;h=002a6962246598ab150f03acc27dc9753fa436f5;hb=refs/heads/master -Will ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ oprofile-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/oprofile-list