Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Liang, Kan
On 12/19/2017 5:07 PM, Peter Zijlstra wrote: On Tue, Dec 19, 2017 at 03:08:58PM -0500, Liang, Kan wrote: This all looks very wrong... In auto reload we should never call intel_pmu_save_and_restore() in the first place I think. Things like x86_perf_event_update() and

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Liang, Kan
On 12/19/2017 5:07 PM, Peter Zijlstra wrote: On Tue, Dec 19, 2017 at 03:08:58PM -0500, Liang, Kan wrote: This all looks very wrong... In auto reload we should never call intel_pmu_save_and_restore() in the first place I think. Things like x86_perf_event_update() and

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Andi Kleen
On Tue, Dec 19, 2017 at 11:07:09PM +0100, Peter Zijlstra wrote: > On Tue, Dec 19, 2017 at 03:08:58PM -0500, Liang, Kan wrote: > > > This all looks very wrong... In auto reload we should never call > > > intel_pmu_save_and_restore() in the first place I think. > > > > > > Things like

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Andi Kleen
On Tue, Dec 19, 2017 at 11:07:09PM +0100, Peter Zijlstra wrote: > On Tue, Dec 19, 2017 at 03:08:58PM -0500, Liang, Kan wrote: > > > This all looks very wrong... In auto reload we should never call > > > intel_pmu_save_and_restore() in the first place I think. > > > > > > Things like

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Peter Zijlstra
On Tue, Dec 19, 2017 at 03:08:58PM -0500, Liang, Kan wrote: > > This all looks very wrong... In auto reload we should never call > > intel_pmu_save_and_restore() in the first place I think. > > > > Things like x86_perf_event_update() and x86_perf_event_set_period() > > simply _cannot_ do the

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Peter Zijlstra
On Tue, Dec 19, 2017 at 03:08:58PM -0500, Liang, Kan wrote: > > This all looks very wrong... In auto reload we should never call > > intel_pmu_save_and_restore() in the first place I think. > > > > Things like x86_perf_event_update() and x86_perf_event_set_period() > > simply _cannot_ do the

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Liang, Kan
On 12/19/2017 3:08 PM, Liang, Kan wrote: On 12/19/2017 1:58 PM, Peter Zijlstra wrote: On Mon, Dec 18, 2017 at 03:34:49AM -0800, kan.li...@linux.intel.com wrote:   arch/x86/events/core.c | 14 ++   arch/x86/events/intel/ds.c |  8 +++-   2 files changed, 21 insertions(+),

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Liang, Kan
On 12/19/2017 3:08 PM, Liang, Kan wrote: On 12/19/2017 1:58 PM, Peter Zijlstra wrote: On Mon, Dec 18, 2017 at 03:34:49AM -0800, kan.li...@linux.intel.com wrote:   arch/x86/events/core.c | 14 ++   arch/x86/events/intel/ds.c |  8 +++-   2 files changed, 21 insertions(+),

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Liang, Kan
On 12/19/2017 1:58 PM, Peter Zijlstra wrote: On Mon, Dec 18, 2017 at 03:34:49AM -0800, kan.li...@linux.intel.com wrote: arch/x86/events/core.c | 14 ++ arch/x86/events/intel/ds.c | 8 +++- 2 files changed, 21 insertions(+), 1 deletion(-) diff --git

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Liang, Kan
On 12/19/2017 1:58 PM, Peter Zijlstra wrote: On Mon, Dec 18, 2017 at 03:34:49AM -0800, kan.li...@linux.intel.com wrote: arch/x86/events/core.c | 14 ++ arch/x86/events/intel/ds.c | 8 +++- 2 files changed, 21 insertions(+), 1 deletion(-) diff --git

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Peter Zijlstra
On Mon, Dec 18, 2017 at 03:34:49AM -0800, kan.li...@linux.intel.com wrote: > arch/x86/events/core.c | 14 ++ > arch/x86/events/intel/ds.c | 8 +++- > 2 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c > index

Re: [PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-19 Thread Peter Zijlstra
On Mon, Dec 18, 2017 at 03:34:49AM -0800, kan.li...@linux.intel.com wrote: > arch/x86/events/core.c | 14 ++ > arch/x86/events/intel/ds.c | 8 +++- > 2 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c > index

[PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-18 Thread kan . liang
From: Kan Liang There is bug when mmap read event->count with large PEBS enabled. Here is an example. #./read_count 0x71f0 0x122c0 0x11c54 0x10001257d 0x2bdc5 There is auto-reload mechanism enabled for PEBS events in fixed period mode. But

[PATCH 2/4] perf/x86/intel: fix event update for auto-reload

2017-12-18 Thread kan . liang
From: Kan Liang There is bug when mmap read event->count with large PEBS enabled. Here is an example. #./read_count 0x71f0 0x122c0 0x11c54 0x10001257d 0x2bdc5 There is auto-reload mechanism enabled for PEBS events in fixed period mode. But the calculation of