Re: [PATCH 0/5] perf: add support for capturing skid IP

On Fri, Jun 16, 2017 at 10:50 AM, Andi Kleen wrote: >> > Yeah, I think it is easier and more portable, especially on hardware with a >> > PEBS-like mechanism but no branch buffer (like LBR). FYI, I did do a test >> > implementation yesterday to evaluate the difficulty. >> >

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Fri, Jun 16, 2017 at 10:50 AM, Andi Kleen wrote: >> > Yeah, I think it is easier and more portable, especially on hardware with a >> > PEBS-like mechanism but no branch buffer (like LBR). FYI, I did do a test >> > implementation yesterday to evaluate the difficulty. >> > >> A more generalized

Re: [PATCH 0/5] perf: add support for capturing skid IP

> > Yeah, I think it is easier and more portable, especially on hardware with a > > PEBS-like mechanism but no branch buffer (like LBR). FYI, I did do a test > > implementation yesterday to evaluate the difficulty. > > > A more generalized usage of the feature is to evaluate the amount of skid >

Re: [PATCH 0/5] perf: add support for capturing skid IP

> > Yeah, I think it is easier and more portable, especially on hardware with a > > PEBS-like mechanism but no branch buffer (like LBR). FYI, I did do a test > > implementation yesterday to evaluate the difficulty. > > > A more generalized usage of the feature is to evaluate the amount of skid >

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Fri, Jun 16, 2017 at 10:08 AM, Stephane Eranian wrote: > On Fri, Jun 16, 2017 at 9:06 AM, Andi Kleen wrote: >> On Thu, Jun 15, 2017 at 11:52:07PM -0700, Stephane Eranian wrote: >>> Andi, >>> >>> On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Fri, Jun 16, 2017 at 10:08 AM, Stephane Eranian wrote: > On Fri, Jun 16, 2017 at 9:06 AM, Andi Kleen wrote: >> On Thu, Jun 15, 2017 at 11:52:07PM -0700, Stephane Eranian wrote: >>> Andi, >>> >>> On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: >>> >> Looking at this approach, the user

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Fri, Jun 16, 2017 at 9:06 AM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 11:52:07PM -0700, Stephane Eranian wrote: >> Andi, >> >> On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: >> >> Looking at this approach, the user interface is

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Fri, Jun 16, 2017 at 9:06 AM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 11:52:07PM -0700, Stephane Eranian wrote: >> Andi, >> >> On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: >> >> Looking at this approach, the user interface is straightforward, >> >> implementation in the x86 code is

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 11:52:07PM -0700, Stephane Eranian wrote: > Andi, > > On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: > >> Looking at this approach, the user interface is straightforward, > >> implementation in the x86 code is a bit more hairy because of the way

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 11:52:07PM -0700, Stephane Eranian wrote: > Andi, > > On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: > >> Looking at this approach, the user interface is straightforward, > >> implementation in the x86 code is a bit more hairy because of the way > >> the branch_stack

Re: [PATCH 0/5] perf: add support for capturing skid IP

Andi, On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: >> Looking at this approach, the user interface is straightforward, >> implementation in the x86 code is a bit more hairy because of the way >> the branch_stack is captured, via the cpuc->lbr_entries. If you assume >>

Re: [PATCH 0/5] perf: add support for capturing skid IP

Andi, On Thu, Jun 15, 2017 at 4:18 PM, Andi Kleen wrote: >> Looking at this approach, the user interface is straightforward, >> implementation in the x86 code is a bit more hairy because of the way >> the branch_stack is captured, via the cpuc->lbr_entries. If you assume >> that SKID_IP cannot

Re: [PATCH 0/5] perf: add support for capturing skid IP

> Looking at this approach, the user interface is straightforward, > implementation in the x86 code is a bit more hairy because of the way > the branch_stack is captured, via the cpuc->lbr_entries. If you assume > that SKID_IP cannot be used with any other branch stack mode, then it > is easy. It

Re: [PATCH 0/5] perf: add support for capturing skid IP

> Looking at this approach, the user interface is straightforward, > implementation in the x86 code is a bit more hairy because of the way > the branch_stack is captured, via the cpuc->lbr_entries. If you assume > that SKID_IP cannot be used with any other branch stack mode, then it > is easy. It

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 1:20 PM, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 1:02 PM, Andi Kleen wrote: >> On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: >>> On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 1:20 PM, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 1:02 PM, Andi Kleen wrote: >> On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: >>> On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: >>> > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 1:02 PM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: >> On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: >> > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: >> >>

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 1:02 PM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: >> On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: >> > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: >> >> On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: > > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: > >> On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: > >> >

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 12:35:39PM -0700, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: > > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: > >> On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: > >> > On Thu, Jun 15, 2017 at 06:56:24AM -0700,

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: >> On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: >> > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: >> >>

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 10:23 AM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: >> On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: >> > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: >> >> This patchs adds a new sample record type

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: > > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: > >> This patchs adds a new sample record type called > >> PERF_SAMPLE_SKID_IP. The

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 09:44:07AM -0700, Stephane Eranian wrote: > On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: > > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: > >> This patchs adds a new sample record type called > >> PERF_SAMPLE_SKID_IP. The goal is to record > >>

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: >> This patchs adds a new sample record type called >> PERF_SAMPLE_SKID_IP. The goal is to record >> the unmodified interrupted instruction pointer (IP) as

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 8:10 AM, Andi Kleen wrote: > On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: >> This patchs adds a new sample record type called >> PERF_SAMPLE_SKID_IP. The goal is to record >> the unmodified interrupted instruction pointer (IP) as seen by >> the kernel

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: > This patchs adds a new sample record type called > PERF_SAMPLE_SKID_IP. The goal is to record > the unmodified interrupted instruction pointer (IP) as seen by > the kernel and reflected in the machine state. Patches look

Re: [PATCH 0/5] perf: add support for capturing skid IP

On Thu, Jun 15, 2017 at 06:56:24AM -0700, Stephane Eranian wrote: > This patchs adds a new sample record type called > PERF_SAMPLE_SKID_IP. The goal is to record > the unmodified interrupted instruction pointer (IP) as seen by > the kernel and reflected in the machine state. Patches look

[PATCH 0/5] perf: add support for capturing skid IP

This patchs adds a new sample record type called PERF_SAMPLE_SKID_IP. The goal is to record the unmodified interrupted instruction pointer (IP) as seen by the kernel and reflected in the machine state. On some architectures, it is possible to avoid the IP skid using hardware support. For

[PATCH 0/5] perf: add support for capturing skid IP

This patchs adds a new sample record type called PERF_SAMPLE_SKID_IP. The goal is to record the unmodified interrupted instruction pointer (IP) as seen by the kernel and reflected in the machine state. On some architectures, it is possible to avoid the IP skid using hardware support. For