| Message ID | 20180925125926.10404-1-prarit@redhat.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Len Brown |
| Headers | show |
| Series | tools/power turbostat: Warn on bad ACPI LPIT data | expand |
Len? P. On 09/25/2018 08:59 AM, Prarit Bhargava wrote: > On some systems /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us > or /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us > return a file error because of bad ACPI LPIT data from a misconfigured BIOS. > turbostat interprets this failure as a fatal error and outputs > > turbostat: CPU LPI: No data available > > If the ACPI LPIT sysfs files return an error output a warning instead of > a fatal error, disable the ACPI LPIT evaluation code, and continue. > > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > Cc: Len Brown <lenb@kernel.org> > --- > tools/power/x86/turbostat/turbostat.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c > index 980bd9d20646..6b81decede49 100644 > --- a/tools/power/x86/turbostat/turbostat.c > +++ b/tools/power/x86/turbostat/turbostat.c > @@ -2831,8 +2831,11 @@ int snapshot_cpu_lpi_us(void) > fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us", "r"); > > retval = fscanf(fp, "%lld", &cpuidle_cur_cpu_lpi_us); > - if (retval != 1) > - err(1, "CPU LPI"); > + if (retval != 1) { > + fprintf(stderr, "Disabling Low Power Idle CPU output\n"); > + BIC_NOT_PRESENT(BIC_CPU_LPI); > + return -1; > + } > > fclose(fp); > > @@ -2854,9 +2857,11 @@ int snapshot_sys_lpi_us(void) > fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us", "r"); > > retval = fscanf(fp, "%lld", &cpuidle_cur_sys_lpi_us); > - if (retval != 1) > - err(1, "SYS LPI"); > - > + if (retval != 1) { > + fprintf(stderr, "Disabling Low Power Idle System output\n"); > + BIC_NOT_PRESENT(BIC_SYS_LPI); > + return -1; > + } > fclose(fp); > > return 0; >
Interesting. What is returned when this fails? While I've applied your patch (thanks!), I wonder if the kernel should really not be exporting these attributes if they don't work... -Len On Mon, Oct 8, 2018 at 11:44 AM Prarit Bhargava <prarit@redhat.com> wrote: > > Len? > > P. > > On 09/25/2018 08:59 AM, Prarit Bhargava wrote: > > On some systems /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us > > or /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us > > return a file error because of bad ACPI LPIT data from a misconfigured BIOS. > > turbostat interprets this failure as a fatal error and outputs > > > > turbostat: CPU LPI: No data available > > > > If the ACPI LPIT sysfs files return an error output a warning instead of > > a fatal error, disable the ACPI LPIT evaluation code, and continue. > > > > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > > Cc: Len Brown <lenb@kernel.org> > > --- > > tools/power/x86/turbostat/turbostat.c | 15 ++++++++++----- > > 1 file changed, 10 insertions(+), 5 deletions(-) > > > > diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c > > index 980bd9d20646..6b81decede49 100644 > > --- a/tools/power/x86/turbostat/turbostat.c > > +++ b/tools/power/x86/turbostat/turbostat.c > > @@ -2831,8 +2831,11 @@ int snapshot_cpu_lpi_us(void) > > fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us", "r"); > > > > retval = fscanf(fp, "%lld", &cpuidle_cur_cpu_lpi_us); > > - if (retval != 1) > > - err(1, "CPU LPI"); > > + if (retval != 1) { > > + fprintf(stderr, "Disabling Low Power Idle CPU output\n"); > > + BIC_NOT_PRESENT(BIC_CPU_LPI); > > + return -1; > > + } > > > > fclose(fp); > > > > @@ -2854,9 +2857,11 @@ int snapshot_sys_lpi_us(void) > > fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us", "r"); > > > > retval = fscanf(fp, "%lld", &cpuidle_cur_sys_lpi_us); > > - if (retval != 1) > > - err(1, "SYS LPI"); > > - > > + if (retval != 1) { > > + fprintf(stderr, "Disabling Low Power Idle System output\n"); > > + BIC_NOT_PRESENT(BIC_SYS_LPI); > > + return -1; > > + } > > fclose(fp); > > > > return 0; > >
On 3/20/19 11:14 PM, Len Brown wrote: > Interesting. What is returned when this fails? > ISTR I got an error that just said "CPU LPI: no data available". I'll have to dig back through my notes to find the bug that was filed. > While I've applied your patch (thanks!), I wonder if the kernel should > really not be exporting these attributes if they don't work... > I dunno if it is up to the kernel to determine the validity of the contents of a table? That could be a slippery slope. Also when I pointed out to the customer that this is an issue with their ACPI tables they did respond back that they agreed and they required a fix. P. > -Len > > On Mon, Oct 8, 2018 at 11:44 AM Prarit Bhargava <prarit@redhat.com> wrote: >> >> Len? >> >> P. >> >> On 09/25/2018 08:59 AM, Prarit Bhargava wrote: >>> On some systems /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us >>> or /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us >>> return a file error because of bad ACPI LPIT data from a misconfigured BIOS. >>> turbostat interprets this failure as a fatal error and outputs >>> >>> turbostat: CPU LPI: No data available >>> >>> If the ACPI LPIT sysfs files return an error output a warning instead of >>> a fatal error, disable the ACPI LPIT evaluation code, and continue. >>> >>> Signed-off-by: Prarit Bhargava <prarit@redhat.com> >>> Cc: Len Brown <lenb@kernel.org> >>> --- >>> tools/power/x86/turbostat/turbostat.c | 15 ++++++++++----- >>> 1 file changed, 10 insertions(+), 5 deletions(-) >>> >>> diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c >>> index 980bd9d20646..6b81decede49 100644 >>> --- a/tools/power/x86/turbostat/turbostat.c >>> +++ b/tools/power/x86/turbostat/turbostat.c >>> @@ -2831,8 +2831,11 @@ int snapshot_cpu_lpi_us(void) >>> fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us", "r"); >>> >>> retval = fscanf(fp, "%lld", &cpuidle_cur_cpu_lpi_us); >>> - if (retval != 1) >>> - err(1, "CPU LPI"); >>> + if (retval != 1) { >>> + fprintf(stderr, "Disabling Low Power Idle CPU output\n"); >>> + BIC_NOT_PRESENT(BIC_CPU_LPI); >>> + return -1; >>> + } >>> >>> fclose(fp); >>> >>> @@ -2854,9 +2857,11 @@ int snapshot_sys_lpi_us(void) >>> fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us", "r"); >>> >>> retval = fscanf(fp, "%lld", &cpuidle_cur_sys_lpi_us); >>> - if (retval != 1) >>> - err(1, "SYS LPI"); >>> - >>> + if (retval != 1) { >>> + fprintf(stderr, "Disabling Low Power Idle System output\n"); >>> + BIC_NOT_PRESENT(BIC_SYS_LPI); >>> + return -1; >>> + } >>> fclose(fp); >>> >>> return 0; >>> > > >
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index 980bd9d20646..6b81decede49 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -2831,8 +2831,11 @@ int snapshot_cpu_lpi_us(void) fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us", "r"); retval = fscanf(fp, "%lld", &cpuidle_cur_cpu_lpi_us); - if (retval != 1) - err(1, "CPU LPI"); + if (retval != 1) { + fprintf(stderr, "Disabling Low Power Idle CPU output\n"); + BIC_NOT_PRESENT(BIC_CPU_LPI); + return -1; + } fclose(fp); @@ -2854,9 +2857,11 @@ int snapshot_sys_lpi_us(void) fp = fopen_or_die("/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us", "r"); retval = fscanf(fp, "%lld", &cpuidle_cur_sys_lpi_us); - if (retval != 1) - err(1, "SYS LPI"); - + if (retval != 1) { + fprintf(stderr, "Disabling Low Power Idle System output\n"); + BIC_NOT_PRESENT(BIC_SYS_LPI); + return -1; + } fclose(fp); return 0;
On some systems /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us or /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us return a file error because of bad ACPI LPIT data from a misconfigured BIOS. turbostat interprets this failure as a fatal error and outputs turbostat: CPU LPI: No data available If the ACPI LPIT sysfs files return an error output a warning instead of a fatal error, disable the ACPI LPIT evaluation code, and continue. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Len Brown <lenb@kernel.org> --- tools/power/x86/turbostat/turbostat.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)