| Message ID | 1551283518-18922-10-git-send-email-ricardo.neri-calderon@linux.intel.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
| Series | None | expand |
On Wed, Feb 27, 2019 at 08:05:13AM -0800, Ricardo Neri wrote: > CPU architectures that have an NMI watchdog use arch_touch_nmi_watchdog() > to briefly ignore the hardlockup detector. If the architecture does not > have an NMI watchdog, one can be constructed using a source of non- > maskable interrupts. In this case, arch_touch_nmi_watchdog() is common > to any underlying hardware resource used to drive the detector and needs > to be available to other kernel subsystems if hardware different from perf > drives the detector. > > There exists perf-based and HPET-based implementations. Make it available > to the latter. > > For clarity, wrap this function in a separate preprocessor conditional > from functions which are truly specific to the perf-based implementation. > > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Ashok Raj <ashok.raj@intel.com> > Cc: Andi Kleen <andi.kleen@intel.com> > Cc: Tony Luck <tony.luck@intel.com> > Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> > Cc: Don Zickus <dzickus@redhat.com> > Cc: Nicholas Piggin <npiggin@gmail.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Frederic Weisbecker <frederic@kernel.org> > Cc: Alexei Starovoitov <ast@kernel.org> > Cc: Babu Moger <babu.moger@oracle.com> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Cc: Masami Hiramatsu <mhiramat@kernel.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Philippe Ombredanne <pombredanne@nexb.com> > Cc: Colin Ian King <colin.king@canonical.com> > Cc: Byungchul Park <byungchul.park@lge.com> > Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> > Cc: Waiman Long <longman@redhat.com> > Cc: Josh Poimboeuf <jpoimboe@redhat.com> > Cc: Randy Dunlap <rdunlap@infradead.org> > Cc: Davidlohr Bueso <dave@stgolabs.net> > Cc: Christoffer Dall <cdall@linaro.org> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: David Rientjes <rientjes@google.com> > Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> > Cc: x86@kernel.org > Cc: sparclinux@vger.kernel.org > Cc: linuxppc-dev@lists.ozlabs.org > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> > --- > include/linux/nmi.h | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/include/linux/nmi.h b/include/linux/nmi.h > index 5a8b19749769..bf5ebcfdd590 100644 > --- a/include/linux/nmi.h > +++ b/include/linux/nmi.h > @@ -94,8 +94,16 @@ static inline void hardlockup_detector_disable(void) {} > # define NMI_WATCHDOG_SYSCTL_PERM 0444 > #endif > > -#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) > +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) || \ > + defined(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET) Why not instead make CONFIG_X86_HARDLOCKUP_DETECTOR_HPET select CONFIG_HARDLOCKUP_DETECTOR_PERF? Keep the arch-specific details in the arch-specific files and all that. Thanx, Paul > extern void arch_touch_nmi_watchdog(void); > +#else > +# if !defined(CONFIG_HAVE_NMI_WATCHDOG) > +static inline void arch_touch_nmi_watchdog(void) {} > +# endif > +#endif > + > +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) > extern void hardlockup_detector_perf_stop(void); > extern void hardlockup_detector_perf_restart(void); > extern void hardlockup_detector_perf_disable(void); > -- > 2.17.1 >
On Wed, Feb 27, 2019 at 08:17:58AM -0800, Paul E. McKenney wrote: > On Wed, Feb 27, 2019 at 08:05:13AM -0800, Ricardo Neri wrote: > > CPU architectures that have an NMI watchdog use arch_touch_nmi_watchdog() > > to briefly ignore the hardlockup detector. If the architecture does not > > have an NMI watchdog, one can be constructed using a source of non- > > maskable interrupts. In this case, arch_touch_nmi_watchdog() is common > > to any underlying hardware resource used to drive the detector and needs > > to be available to other kernel subsystems if hardware different from perf > > drives the detector. > > > > There exists perf-based and HPET-based implementations. Make it available > > to the latter. > > > > For clarity, wrap this function in a separate preprocessor conditional > > from functions which are truly specific to the perf-based implementation. > > > > Cc: "H. Peter Anvin" <hpa@zytor.com> > > Cc: Ashok Raj <ashok.raj@intel.com> > > Cc: Andi Kleen <andi.kleen@intel.com> > > Cc: Tony Luck <tony.luck@intel.com> > > Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> > > Cc: Don Zickus <dzickus@redhat.com> > > Cc: Nicholas Piggin <npiggin@gmail.com> > > Cc: Michael Ellerman <mpe@ellerman.id.au> > > Cc: Frederic Weisbecker <frederic@kernel.org> > > Cc: Alexei Starovoitov <ast@kernel.org> > > Cc: Babu Moger <babu.moger@oracle.com> > > Cc: "David S. Miller" <davem@davemloft.net> > > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > > Cc: Paul Mackerras <paulus@samba.org> > > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > > Cc: Masami Hiramatsu <mhiramat@kernel.org> > > Cc: Peter Zijlstra <peterz@infradead.org> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Philippe Ombredanne <pombredanne@nexb.com> > > Cc: Colin Ian King <colin.king@canonical.com> > > Cc: Byungchul Park <byungchul.park@lge.com> > > Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > > Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> > > Cc: Waiman Long <longman@redhat.com> > > Cc: Josh Poimboeuf <jpoimboe@redhat.com> > > Cc: Randy Dunlap <rdunlap@infradead.org> > > Cc: Davidlohr Bueso <dave@stgolabs.net> > > Cc: Christoffer Dall <cdall@linaro.org> > > Cc: Marc Zyngier <marc.zyngier@arm.com> > > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com> > > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > Cc: David Rientjes <rientjes@google.com> > > Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> > > Cc: x86@kernel.org > > Cc: sparclinux@vger.kernel.org > > Cc: linuxppc-dev@lists.ozlabs.org > > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> > > --- > > include/linux/nmi.h | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/include/linux/nmi.h b/include/linux/nmi.h > > index 5a8b19749769..bf5ebcfdd590 100644 > > --- a/include/linux/nmi.h > > +++ b/include/linux/nmi.h > > @@ -94,8 +94,16 @@ static inline void hardlockup_detector_disable(void) {} > > # define NMI_WATCHDOG_SYSCTL_PERM 0444 > > #endif > > > > -#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) > > +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) || \ > > + defined(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET) > > Why not instead make CONFIG_X86_HARDLOCKUP_DETECTOR_HPET select > CONFIG_HARDLOCKUP_DETECTOR_PERF? Keep the arch-specific details > in the arch-specific files and all that. Thanks for your feedback, Paul! The HPET implementation does not use perf. Thus, in my opinion is not correct for the HPET HLD to select the perf implementation. Patch 8 of this series splits the perf-specific code and the generic hardlockup detector code. Does this make sense? Thanks and BR, Ricardo
On Thu, 28 Feb 2019, Ricardo Neri wrote: > > > > > > -#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) > > > +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) || \ > > > + defined(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET) > > > > Why not instead make CONFIG_X86_HARDLOCKUP_DETECTOR_HPET select > > CONFIG_HARDLOCKUP_DETECTOR_PERF? Keep the arch-specific details > > in the arch-specific files and all that. > > Thanks for your feedback, Paul! The HPET implementation does not use > perf. Thus, in my opinion is not correct for the HPET HLD to select > the perf implementation. Patch 8 of this series splits the perf-specific > code and the generic hardlockup detector code. Does this make sense? That's what intermediate config symbols are for. config HARDLOCKUP_DETECTOR_CORE bool And make both PERF and HPET select it. Thanks, tglx
On Tue, Mar 26, 2019 at 10:20:41PM +0100, Thomas Gleixner wrote: > On Thu, 28 Feb 2019, Ricardo Neri wrote: > > > > > > > > -#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) > > > > +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) || \ > > > > + defined(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET) > > > > > > Why not instead make CONFIG_X86_HARDLOCKUP_DETECTOR_HPET select > > > CONFIG_HARDLOCKUP_DETECTOR_PERF? Keep the arch-specific details > > > in the arch-specific files and all that. > > > > Thanks for your feedback, Paul! The HPET implementation does not use > > perf. Thus, in my opinion is not correct for the HPET HLD to select > > the perf implementation. Patch 8 of this series splits the perf-specific > > code and the generic hardlockup detector code. Does this make sense? > > That's what intermediate config symbols are for. > > config HARDLOCKUP_DETECTOR_CORE > bool > > And make both PERF and HPET select it. I'll implement it in this manner. Thanks and BR, Ricardo
diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 5a8b19749769..bf5ebcfdd590 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -94,8 +94,16 @@ static inline void hardlockup_detector_disable(void) {} # define NMI_WATCHDOG_SYSCTL_PERM 0444 #endif -#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) || \ + defined(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET) extern void arch_touch_nmi_watchdog(void); +#else +# if !defined(CONFIG_HAVE_NMI_WATCHDOG) +static inline void arch_touch_nmi_watchdog(void) {} +# endif +#endif + +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) extern void hardlockup_detector_perf_stop(void); extern void hardlockup_detector_perf_restart(void); extern void hardlockup_detector_perf_disable(void);
CPU architectures that have an NMI watchdog use arch_touch_nmi_watchdog() to briefly ignore the hardlockup detector. If the architecture does not have an NMI watchdog, one can be constructed using a source of non- maskable interrupts. In this case, arch_touch_nmi_watchdog() is common to any underlying hardware resource used to drive the detector and needs to be available to other kernel subsystems if hardware different from perf drives the detector. There exists perf-based and HPET-based implementations. Make it available to the latter. For clarity, wrap this function in a separate preprocessor conditional from functions which are truly specific to the perf-based implementation. Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Babu Moger <babu.moger@oracle.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Christoffer Dall <cdall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com> Cc: x86@kernel.org Cc: sparclinux@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- include/linux/nmi.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)