[PATCH] i386 make NMI use PERFCTR1 for architectural perfmon
Hello, This patch against 2.6.20 makes the NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural perfmon, such as Intel Core 2. Although all PMU events can work on both counters, the Precise Event-Based Sampling (PEBS) requires that the event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the IA32 SDM Vol 3b). A similar patch for x86-64 is to follow. Changelog: - make the i386 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0 on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo). This allows PEBS to work when the NMI watchdog is active. signed-off-by: stephane eranian <[EMAIL PROTECTED]> diff -urNp --exclude=.git linux-2.6.20.orig/arch/i386/kernel/nmi.c linux-2.6.20.base/arch/i386/kernel/nmi.c --- linux-2.6.20.orig/arch/i386/kernel/nmi.c2007-02-04 10:44:54.0 -0800 +++ linux-2.6.20.base/arch/i386/kernel/nmi.c2007-02-17 07:59:41.0 -0800 @@ -288,7 +288,7 @@ static int __init check_nmi_watchdog(voi * 32nd bit should be 1, for 33.. to be 1. * Find the appropriate nmi_hz */ - if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0 && + if (wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1 && ((u64)cpu_khz * 1000) > 0x7fffULL) { u64 count = (u64)cpu_khz * 1000; do_div(count, 0x7fffUL); @@ -685,8 +685,8 @@ static int setup_intel_arch_watchdog(voi (ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) goto fail; - perfctr_msr = MSR_ARCH_PERFMON_PERFCTR0; - evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL0; + perfctr_msr = MSR_ARCH_PERFMON_PERFCTR1; + evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL1; if (!reserve_perfctr_nmi(perfctr_msr)) goto fail; @@ -958,7 +958,7 @@ __kprobes int nmi_watchdog_tick(struct p apic_write(APIC_LVTPC, APIC_DM_NMI); } else if (wd->perfctr_msr == MSR_P6_PERFCTR0 || -wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) { +wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) { /* P6 based Pentium M need to re-unmask * the apic vector but it doesn't hurt * other P6 variant. -- -Stephane - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] i386 make NMI use PERFCTR1 for architectural perfmon
On Saturday 17 February 2007 17:06, Stephane Eranian wrote: > Hello, > > This patch against 2.6.20 Please always submit against mainline: patching file arch/i386/kernel/nmi.c Hunk #1 FAILED at 288. Hunk #2 succeeded at 740 (offset 55 lines). Hunk #3 succeeded at 1017 with fuzz 1 (offset 59 lines). 1 out of 3 hunks FAILED -- rejects in file arch/i386/kernel/nmi.c Patch patches/i386-make-nmi-use-perfctr1-for-architectural-perfmon does not apply (enforce with -f) -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] i386 make NMI use PERFCTR1 for architectural perfmon
Andi, On Sun, Feb 18, 2007 at 05:56:05PM +0100, Andi Kleen wrote: > On Saturday 17 February 2007 17:06, Stephane Eranian wrote: > > Hello, > > > > This patch against 2.6.20 > > Please always submit against mainline: > Isn't 2.6.20 the latest mainline? > patching file arch/i386/kernel/nmi.c > Hunk #1 FAILED at 288. > Hunk #2 succeeded at 740 (offset 55 lines). > Hunk #3 succeeded at 1017 with fuzz 1 (offset 59 lines). > 1 out of 3 hunks FAILED -- rejects in file arch/i386/kernel/nmi.c > Patch patches/i386-make-nmi-use-perfctr1-for-architectural-perfmon does not > apply (enforce with -f) > Maybe I messed up my original tree. Do you want me to resubmit? Sorry about that. -- -Stephane - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] i386 make NMI use PERFCTR1 for architectural perfmon
On Monday 19 February 2007 17:36, Stephane Eranian wrote: > Andi, > > On Sun, Feb 18, 2007 at 05:56:05PM +0100, Andi Kleen wrote: > > On Saturday 17 February 2007 17:06, Stephane Eranian wrote: > > > Hello, > > > > > > This patch against 2.6.20 > > > > Please always submit against mainline: > > > Isn't 2.6.20 the latest mainline? ftp://ftp.kernel.org/pub/linux/kernel/v2.6/snapshots/patch-2.6.20-git* is > Do you want me to resubmit? Yes please. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] i386 make NMI use PERFCTR1 for architectural perfmon (take 2)
Hello, This patch against 2.6.20-git14 makes the NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural perfmon, such as Intel Core 2. Although all PMU events can work on both counters, the Precise Event-Based Sampling (PEBS) requires that the event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the IA32 SDM Vol 3b). A similar patch for x86-64 is to follow. Changelog: - make the i386 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0 on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo). This allows PEBS to work when the NMI watchdog is active. signed-off-by: stephane eranian <[EMAIL PROTECTED]> diff -urNp --exclude=.git linux-2.6.20.orig/arch/i386/kernel/nmi.c linux-2.6.20.base/arch/i386/kernel/nmi.c --- linux-2.6.20.orig/arch/i386/kernel/nmi.c2007-02-19 13:37:26.0 -0800 +++ linux-2.6.20.base/arch/i386/kernel/nmi.c2007-02-19 13:54:42.0 -0800 @@ -307,7 +307,7 @@ static int __init check_nmi_watchdog(voi nmi_hz = 1; if (wd->perfctr_msr == MSR_P6_PERFCTR0 || - wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) { + wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) { nmi_hz = adjust_for_32bit_ctr(nmi_hz); } } @@ -741,8 +741,8 @@ static int setup_intel_arch_watchdog(voi (ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) goto fail; - perfctr_msr = MSR_ARCH_PERFMON_PERFCTR0; - evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL0; + perfctr_msr = MSR_ARCH_PERFMON_PERFCTR1; + evntsel_msr = MSR_ARCH_PERFMON_EVENTSEL1; if (!reserve_perfctr_nmi(perfctr_msr)) goto fail; @@ -1022,7 +1022,7 @@ __kprobes int nmi_watchdog_tick(struct p write_watchdog_counter(wd->perfctr_msr, NULL); } else if (wd->perfctr_msr == MSR_P6_PERFCTR0 || -wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR0) { +wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) { /* P6 based Pentium M need to re-unmask * the apic vector but it doesn't hurt * other P6 variant. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/