On Tue, May 25, 2010 at 3:35 PM, Peter Zijlstra <pet...@infradead.org> wrote: > On Tue, 2010-05-25 at 15:20 +0200, Stephane Eranian wrote: > >> With this patch, you can now overcommit the PMU even with pinned >> system-wide events present and still get valid counts. > > Does this patch differ from the one you send earlier? > Yes, it does. It changes the way n_added is updated.
The first version was buggy (perf top would crash the machine). You cannot delay updating n_added until commit, because there are paths where you don't go through transactions. This version instead keeps the number of events last added and speculatively updates n_added (assuming success). If the transaction succeeds, then no correction is done (subtracting 0), if it fails, then the number of events just added to n_added is subtracted. ------------------------------------------------------------------------------ _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
