2023-10-03 05:08:32

by Wyes Karny

Subject: [PATCH v2] tools/power turbostat: Increase the limit for fd opened

When running turbostat, a system with 512 cpus reaches the limit for
maximum number of file descriptors that can be opened. To solve this
problem, the limit is raised to 2^15, which is a large enough number.

Below data is collected from AMD server systems while running turbostat:

|-----------+-------------------------------|
| # of cpus | # of opened fds for turbostat |
|-----------+-------------------------------|
| 128 | 260 |
|-----------+-------------------------------|
| 192 | 388 |
|-----------+-------------------------------|
| 512 | 1028 |
|-----------+-------------------------------|

So, the new max limit would be sufficient up to 2^14 cpus (but this
also depends on how many counters are enabled).

Reviewed-by: Doug Smythies <[email protected]>
Tested-by: Doug Smythies <[email protected]>
Signed-off-by: Wyes Karny <[email protected]>
---
v1 -> v2:
- Take care of already higher rlim_max, rlim_curr
- Minor tweak in commit text

tools/power/x86/turbostat/turbostat.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 9a10512e3407..1563a0ae7e4c 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -53,6 +53,8 @@
#define NAME_BYTES 20
#define PATH_BYTES 128

+#define MAX_NOFILE 0x8000
+
enum counter_scope { SCOPE_CPU, SCOPE_CORE, SCOPE_PACKAGE };
enum counter_type { COUNTER_ITEMS, COUNTER_CYCLES, COUNTER_SECONDS, COUNTER_USEC };
enum counter_format { FORMAT_RAW, FORMAT_DELTA, FORMAT_PERCENT };
@@ -6717,6 +6719,22 @@ void cmdline(int argc, char **argv)
}
}

+void set_rlimit(void)
+{
+ struct rlimit limit;
+
+ if (getrlimit(RLIMIT_NOFILE, &limit) < 0)
+ err(1, "Failed to get rlimit");
+
+ if (limit.rlim_max < MAX_NOFILE)
+ limit.rlim_max = MAX_NOFILE;
+ if (limit.rlim_cur < MAX_NOFILE)
+ limit.rlim_cur = MAX_NOFILE;
+
+ if (setrlimit(RLIMIT_NOFILE, &limit) < 0)
+ err(1, "Failed to set rlimit");
+}
+
int main(int argc, char **argv)
{
outf = stderr;
@@ -6729,6 +6747,9 @@ int main(int argc, char **argv)

probe_sysfs();

+ if (!getuid())
+ set_rlimit();
+
turbostat_init();

msr_sum_record();
--
2.34.1

2023-11-02 15:02:15

by Wyes Karny

Subject: Re: [PATCH v2] tools/power turbostat: Increase the limit for fd opened

Gentle ping.

Thanks,
Wyes

On 03 Oct 05:07, Wyes Karny wrote:
> When running turbostat, a system with 512 cpus reaches the limit for
> maximum number of file descriptors that can be opened. To solve this
> problem, the limit is raised to 2^15, which is a large enough number.
>
> Below data is collected from AMD server systems while running turbostat:
>
> |-----------+-------------------------------|
> | # of cpus | # of opened fds for turbostat |
> |-----------+-------------------------------|
> | 128 | 260 |
> |-----------+-------------------------------|
> | 192 | 388 |
> |-----------+-------------------------------|
> | 512 | 1028 |
> |-----------+-------------------------------|
>
> So, the new max limit would be sufficient up to 2^14 cpus (but this
> also depends on how many counters are enabled).
>
> Reviewed-by: Doug Smythies <[email protected]>
> Tested-by: Doug Smythies <[email protected]>
> Signed-off-by: Wyes Karny <[email protected]>
> ---
> v1 -> v2:
> - Take care of already higher rlim_max, rlim_curr
> - Minor tweak in commit text
>
> tools/power/x86/turbostat/turbostat.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
> index 9a10512e3407..1563a0ae7e4c 100644
> --- a/tools/power/x86/turbostat/turbostat.c
> +++ b/tools/power/x86/turbostat/turbostat.c
> @@ -53,6 +53,8 @@
> #define NAME_BYTES 20
> #define PATH_BYTES 128
>
> +#define MAX_NOFILE 0x8000
> +
> enum counter_scope { SCOPE_CPU, SCOPE_CORE, SCOPE_PACKAGE };
> enum counter_type { COUNTER_ITEMS, COUNTER_CYCLES, COUNTER_SECONDS, COUNTER_USEC };
> enum counter_format { FORMAT_RAW, FORMAT_DELTA, FORMAT_PERCENT };
> @@ -6717,6 +6719,22 @@ void cmdline(int argc, char **argv)
> }
> }
>
> +void set_rlimit(void)
> +{
> + struct rlimit limit;
> +
> + if (getrlimit(RLIMIT_NOFILE, &limit) < 0)
> + err(1, "Failed to get rlimit");
> +
> + if (limit.rlim_max < MAX_NOFILE)
> + limit.rlim_max = MAX_NOFILE;
> + if (limit.rlim_cur < MAX_NOFILE)
> + limit.rlim_cur = MAX_NOFILE;
> +
> + if (setrlimit(RLIMIT_NOFILE, &limit) < 0)
> + err(1, "Failed to set rlimit");
> +}
> +
> int main(int argc, char **argv)
> {
> outf = stderr;
> @@ -6729,6 +6747,9 @@ int main(int argc, char **argv)
>
> probe_sysfs();
>
> + if (!getuid())
> + set_rlimit();
> +
> turbostat_init();
>
> msr_sum_record();
> --
> 2.34.1
>

2023-11-28 01:48:23

by Len Brown

Subject: Re: [PATCH v2] tools/power turbostat: Increase the limit for fd opened

Applied

Thanks Wyes!

On Tue, Oct 3, 2023 at 1:08 AM Wyes Karny <[email protected]> wrote:
>
> When running turbostat, a system with 512 cpus reaches the limit for
> maximum number of file descriptors that can be opened. To solve this
> problem, the limit is raised to 2^15, which is a large enough number.
>
> Below data is collected from AMD server systems while running turbostat:
>
> |-----------+-------------------------------|
> | # of cpus | # of opened fds for turbostat |
> |-----------+-------------------------------|
> | 128 | 260 |
> |-----------+-------------------------------|
> | 192 | 388 |
> |-----------+-------------------------------|
> | 512 | 1028 |
> |-----------+-------------------------------|
>
> So, the new max limit would be sufficient up to 2^14 cpus (but this
> also depends on how many counters are enabled).
>
> Reviewed-by: Doug Smythies <[email protected]>
> Tested-by: Doug Smythies <[email protected]>
> Signed-off-by: Wyes Karny <[email protected]>
> ---
> v1 -> v2:
> - Take care of already higher rlim_max, rlim_curr
> - Minor tweak in commit text
>
> tools/power/x86/turbostat/turbostat.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
> index 9a10512e3407..1563a0ae7e4c 100644
> --- a/tools/power/x86/turbostat/turbostat.c
> +++ b/tools/power/x86/turbostat/turbostat.c
> @@ -53,6 +53,8 @@
> #define NAME_BYTES 20
> #define PATH_BYTES 128
>
> +#define MAX_NOFILE 0x8000
> +
> enum counter_scope { SCOPE_CPU, SCOPE_CORE, SCOPE_PACKAGE };
> enum counter_type { COUNTER_ITEMS, COUNTER_CYCLES, COUNTER_SECONDS, COUNTER_USEC };
> enum counter_format { FORMAT_RAW, FORMAT_DELTA, FORMAT_PERCENT };
> @@ -6717,6 +6719,22 @@ void cmdline(int argc, char **argv)
> }
> }
>
> +void set_rlimit(void)
> +{
> + struct rlimit limit;
> +
> + if (getrlimit(RLIMIT_NOFILE, &limit) < 0)
> + err(1, "Failed to get rlimit");
> +
> + if (limit.rlim_max < MAX_NOFILE)
> + limit.rlim_max = MAX_NOFILE;
> + if (limit.rlim_cur < MAX_NOFILE)
> + limit.rlim_cur = MAX_NOFILE;
> +
> + if (setrlimit(RLIMIT_NOFILE, &limit) < 0)
> + err(1, "Failed to set rlimit");
> +}
> +
> int main(int argc, char **argv)
> {
> outf = stderr;
> @@ -6729,6 +6747,9 @@ int main(int argc, char **argv)
>
> probe_sysfs();
>
> + if (!getuid())
> + set_rlimit();
> +
> turbostat_init();
>
> msr_sum_record();
> --
> 2.34.1
>


--
Len Brown, Intel