Re: [PATCH v2 0/2] Stop Intel Processor Trace logging on panic
On 2015/11/12 21:38, Peter Zijlstra wrote: > On Thu, Nov 12, 2015 at 09:05:11PM +0900, Takao Indoh wrote: >> Ping, any comments on these patches? >> > > I've taken them, they should appear in tip sometime after the merge > window closes. > Ok, thanks. Thanks, Takao Indoh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 0/2] Stop Intel Processor Trace logging on panic
On Thu, Nov 12, 2015 at 09:05:11PM +0900, Takao Indoh wrote: > Ping, any comments on these patches? > I've taken them, they should appear in tip sometime after the merge window closes. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 0/2] Stop Intel Processor Trace logging on panic
Ping, any comments on these patches? Thanks, Takao Indoh On 2015/11/04 14:22, Takao Indoh wrote: > Hi all, > > These patch series provide a feature to stop Intel Processor Trace > (Intel PT) logging and save its registers in the memory on panic. > > Intel PT is a new feature of Intel CPU "Broadwell", it captures > information about program execution flow. Here is a article about Intel > PT. > https://software.intel.com/en-us/blogs/2013/09/18/processor-tracing > > Once Intel PT is enabled, the events which change program flow, like > branch instructions, exceptions, interruptions, traps and so on are > logged in the memory. This is very useful for debugging because we can > know the detailed behavior of software. > > When kernel panic occurs while you are running a perf command with Intel > PT (with -e intel_pt// option), these patches disable Intel PT and save > its registers in the memory. After crash dump is captured by kdump, you > can retrieve Intel PT log buffer from vmcore and investigate kernel > behavior. I have not made a tool yet to salvage Intel PT log buffer from > vmcore, but I'll do once these patches are accepted. > > changelog: > v2: > - Define function in intel_pt.h with static inline > > v1: > https://lkml.org/lkml/2015/10/28/136 > > > Background: > These patches are a part of patch series I posted before, the original > discussion is bellow. > > x86: Intel Processor Trace Logger > v1: https://lkml.org/lkml/2015/7/29/6 > v2: https://lkml.org/lkml/2015/9/8/24 > > The purpose of the original patches is introducing in-kernel logger > using Intel PT. To implement it I need to add some APIs to control perf > counter and ring buffer in kernel. Alexander Shishkin is working on such > APIs for his work to make use of Intel PT for process core dump. Apart > from such APIs, the feature to save Intel PT registers on panic is > helpful for normal perf command user as I described above, therefore I > separate the feature from original patches. > > Takao Indoh (2): >perf/x86/intel/pt: Add interface to stop Intel PT logging >x86: Stop Intel PT before kdump starts > > arch/x86/include/asm/intel_pt.h | 10 ++ > arch/x86/kernel/cpu/perf_event_intel_pt.c |9 + > arch/x86/kernel/crash.c | 11 +++ > 3 files changed, 30 insertions(+), 0 deletions(-) > create mode 100644 arch/x86/include/asm/intel_pt.h > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2 0/2] Stop Intel Processor Trace logging on panic
Hi all, These patch series provide a feature to stop Intel Processor Trace (Intel PT) logging and save its registers in the memory on panic. Intel PT is a new feature of Intel CPU "Broadwell", it captures information about program execution flow. Here is a article about Intel PT. https://software.intel.com/en-us/blogs/2013/09/18/processor-tracing Once Intel PT is enabled, the events which change program flow, like branch instructions, exceptions, interruptions, traps and so on are logged in the memory. This is very useful for debugging because we can know the detailed behavior of software. When kernel panic occurs while you are running a perf command with Intel PT (with -e intel_pt// option), these patches disable Intel PT and save its registers in the memory. After crash dump is captured by kdump, you can retrieve Intel PT log buffer from vmcore and investigate kernel behavior. I have not made a tool yet to salvage Intel PT log buffer from vmcore, but I'll do once these patches are accepted. changelog: v2: - Define function in intel_pt.h with static inline v1: https://lkml.org/lkml/2015/10/28/136 Background: These patches are a part of patch series I posted before, the original discussion is bellow. x86: Intel Processor Trace Logger v1: https://lkml.org/lkml/2015/7/29/6 v2: https://lkml.org/lkml/2015/9/8/24 The purpose of the original patches is introducing in-kernel logger using Intel PT. To implement it I need to add some APIs to control perf counter and ring buffer in kernel. Alexander Shishkin is working on such APIs for his work to make use of Intel PT for process core dump. Apart from such APIs, the feature to save Intel PT registers on panic is helpful for normal perf command user as I described above, therefore I separate the feature from original patches. Takao Indoh (2): perf/x86/intel/pt: Add interface to stop Intel PT logging x86: Stop Intel PT before kdump starts arch/x86/include/asm/intel_pt.h | 10 ++ arch/x86/kernel/cpu/perf_event_intel_pt.c |9 + arch/x86/kernel/crash.c | 11 +++ 3 files changed, 30 insertions(+), 0 deletions(-) create mode 100644 arch/x86/include/asm/intel_pt.h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
