Re: [PATCH] perf/x86/intel/cqm: Make sure the head event of cache_groups always has valid RMID

2017-05-22 Thread Shivappa Vikas
Besides there's another bug that we retry rotating without resetting nr_needed and start in __intel_cqm_rmid_rotate(). Those bugs combined together led to the following oops. WARNING: at arch/x86/kernel/cpu/perf_event_intel_cqm.c:186 __put_rmid+0x28/0x80() ... [] __put_rmid+0x28/0x80 [] in

Re: [PATCH] perf/x86/intel/cqm: Make sure the head event of cache_groups always has valid RMID

2017-05-17 Thread David Carrillo-Cisneros
On Tue, May 16, 2017 at 7:38 AM, Peter Zijlstra wrote: > On Thu, May 04, 2017 at 10:31:43AM +0800, Zefan Li wrote: >> It is assumed that the head of cache_groups always has valid RMID, >> which isn't true. >> >> When we deallocate RMID from conflicting events currently we don't >> move them to the

Re: [PATCH] perf/x86/intel/cqm: Make sure the head event of cache_groups always has valid RMID

2017-05-16 Thread Peter Zijlstra
On Thu, May 04, 2017 at 10:31:43AM +0800, Zefan Li wrote: > It is assumed that the head of cache_groups always has valid RMID, > which isn't true. > > When we deallocate RMID from conflicting events currently we don't > move them to the tail, and one of those events can happen to be in > the head.

Re: [PATCH] perf/x86/intel/cqm: Make sure the head event of cache_groups always has valid RMID

2017-05-15 Thread Zefan Li
any comments? On 2017/5/4 10:31, Zefan Li wrote: > It is assumed that the head of cache_groups always has valid RMID, > which isn't true. > > When we deallocate RMID from conflicting events currently we don't > move them to the tail, and one of those events can happen to be in > the head. Another