| Message ID | 20230601155934.296647-1-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | stdlib: Tune down thread arc4random tests | expand |
On 6/1/23 11:59, Adhemerval Zanella via Libc-alpha wrote: > There is no per-thread state on current arc4random implementation, > so limit the maximum number of threads. The tests now run on 1s > instead of 8s on a aarch64 system with 160 cores. I agree this is a good idea... > Checked on aarch64-linux-gnu. > --- > stdlib/tst-arc4random-thread.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c > index 010828920e..4f8cc27b03 100644 > --- a/stdlib/tst-arc4random-thread.c > +++ b/stdlib/tst-arc4random-thread.c > @@ -25,6 +25,7 @@ > #include <support/namespace.h> > #include <support/support.h> > #include <support/xthread.h> > +#include <sys/param.h> > > /* Number of arc4random_buf calls per thread. */ > enum { count_per_thread = 2048 }; > @@ -35,6 +36,9 @@ enum { inner_threads = 4 }; > /* Number of threads launching other threads. */ > static int outer_threads = 1; > > +/* Maximum number of other threads. */ > +enum { max_outer_threads = 4 }; > + > /* Number of launching rounds performed by the outer threads. */ > enum { outer_rounds = 10 }; > > @@ -337,7 +341,8 @@ do_test (void) > { > unsigned int ncpus = CPU_COUNT (&cpuset); > /* Limit the number to not overload the system. */ > - outer_threads = (ncpus / 2) / inner_threads ?: 1; > + outer_threads = MIN ((ncpus / 2) / inner_threads ?: 1, > + max_outer_threads); ... but may you please clean this up a little more? Can we remove the conditional? Use only two values in a MIN condition? > } > > printf ("info: outer_threads=%d inner_threads=%d\n", outer_threads,
On 12/06/23 18:34, Carlos O'Donell wrote: > On 6/1/23 11:59, Adhemerval Zanella via Libc-alpha wrote: >> There is no per-thread state on current arc4random implementation, >> so limit the maximum number of threads. The tests now run on 1s >> instead of 8s on a aarch64 system with 160 cores. > > I agree this is a good idea... > >> Checked on aarch64-linux-gnu. >> --- >> stdlib/tst-arc4random-thread.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c >> index 010828920e..4f8cc27b03 100644 >> --- a/stdlib/tst-arc4random-thread.c >> +++ b/stdlib/tst-arc4random-thread.c >> @@ -25,6 +25,7 @@ >> #include <support/namespace.h> >> #include <support/support.h> >> #include <support/xthread.h> >> +#include <sys/param.h> >> >> /* Number of arc4random_buf calls per thread. */ >> enum { count_per_thread = 2048 }; >> @@ -35,6 +36,9 @@ enum { inner_threads = 4 }; >> /* Number of threads launching other threads. */ >> static int outer_threads = 1; >> >> +/* Maximum number of other threads. */ >> +enum { max_outer_threads = 4 }; >> + >> /* Number of launching rounds performed by the outer threads. */ >> enum { outer_rounds = 10 }; >> >> @@ -337,7 +341,8 @@ do_test (void) >> { >> unsigned int ncpus = CPU_COUNT (&cpuset); >> /* Limit the number to not overload the system. */ >> - outer_threads = (ncpus / 2) / inner_threads ?: 1; >> + outer_threads = MIN ((ncpus / 2) / inner_threads ?: 1, >> + max_outer_threads); > > > ... but may you please clean this up a little more? > > Can we remove the conditional? > > Use only two values in a MIN condition? The '(ncpus / 2) / inner_threads ?: 1' is to avoid having a 0 from the division, and the CPU_COUNT is to avoid having more threads than CPUs. Not sure how more we can simplify it, unless to setup a static maximum number of threads. > >> } >> >> printf ("info: outer_threads=%d inner_threads=%d\n", outer_threads, >
Ping. On 01/06/23 12:59, Adhemerval Zanella wrote: > There is no per-thread state on current arc4random implementation, > so limit the maximum number of threads. The tests now run on 1s > instead of 8s on a aarch64 system with 160 cores. > > Checked on aarch64-linux-gnu. > --- > stdlib/tst-arc4random-thread.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c > index 010828920e..4f8cc27b03 100644 > --- a/stdlib/tst-arc4random-thread.c > +++ b/stdlib/tst-arc4random-thread.c > @@ -25,6 +25,7 @@ > #include <support/namespace.h> > #include <support/support.h> > #include <support/xthread.h> > +#include <sys/param.h> > > /* Number of arc4random_buf calls per thread. */ > enum { count_per_thread = 2048 }; > @@ -35,6 +36,9 @@ enum { inner_threads = 4 }; > /* Number of threads launching other threads. */ > static int outer_threads = 1; > > +/* Maximum number of other threads. */ > +enum { max_outer_threads = 4 }; > + > /* Number of launching rounds performed by the outer threads. */ > enum { outer_rounds = 10 }; > > @@ -337,7 +341,8 @@ do_test (void) > { > unsigned int ncpus = CPU_COUNT (&cpuset); > /* Limit the number to not overload the system. */ > - outer_threads = (ncpus / 2) / inner_threads ?: 1; > + outer_threads = MIN ((ncpus / 2) / inner_threads ?: 1, > + max_outer_threads); > } > > printf ("info: outer_threads=%d inner_threads=%d\n", outer_threads,
On Thu, Jun 1, 2023 at 11:00 AM Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote: > > There is no per-thread state on current arc4random implementation, > so limit the maximum number of threads. The tests now run on 1s > instead of 8s on a aarch64 system with 160 cores. > > Checked on aarch64-linux-gnu. > --- > stdlib/tst-arc4random-thread.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c > index 010828920e..4f8cc27b03 100644 > --- a/stdlib/tst-arc4random-thread.c > +++ b/stdlib/tst-arc4random-thread.c > @@ -25,6 +25,7 @@ > #include <support/namespace.h> > #include <support/support.h> > #include <support/xthread.h> > +#include <sys/param.h> > > /* Number of arc4random_buf calls per thread. */ > enum { count_per_thread = 2048 }; > @@ -35,6 +36,9 @@ enum { inner_threads = 4 }; > /* Number of threads launching other threads. */ > static int outer_threads = 1; > > +/* Maximum number of other threads. */ > +enum { max_outer_threads = 4 }; > + > /* Number of launching rounds performed by the outer threads. */ > enum { outer_rounds = 10 }; > > @@ -337,7 +341,8 @@ do_test (void) > { > unsigned int ncpus = CPU_COUNT (&cpuset); > /* Limit the number to not overload the system. */ > - outer_threads = (ncpus / 2) / inner_threads ?: 1; > + outer_threads = MIN ((ncpus / 2) / inner_threads ?: 1, > + max_outer_threads); Since this is properly no random state how about just MAX(ncpus, 2)? > } > > printf ("info: outer_threads=%d inner_threads=%d\n", outer_threads, > -- > 2.34.1 >
On 02/08/23 13:44, Noah Goldstein wrote: > On Thu, Jun 1, 2023 at 11:00 AM Adhemerval Zanella via Libc-alpha > <libc-alpha@sourceware.org> wrote: >> >> There is no per-thread state on current arc4random implementation, >> so limit the maximum number of threads. The tests now run on 1s >> instead of 8s on a aarch64 system with 160 cores. >> >> Checked on aarch64-linux-gnu. >> --- >> stdlib/tst-arc4random-thread.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c >> index 010828920e..4f8cc27b03 100644 >> --- a/stdlib/tst-arc4random-thread.c >> +++ b/stdlib/tst-arc4random-thread.c >> @@ -25,6 +25,7 @@ >> #include <support/namespace.h> >> #include <support/support.h> >> #include <support/xthread.h> >> +#include <sys/param.h> >> >> /* Number of arc4random_buf calls per thread. */ >> enum { count_per_thread = 2048 }; >> @@ -35,6 +36,9 @@ enum { inner_threads = 4 }; >> /* Number of threads launching other threads. */ >> static int outer_threads = 1; >> >> +/* Maximum number of other threads. */ >> +enum { max_outer_threads = 4 }; >> + >> /* Number of launching rounds performed by the outer threads. */ >> enum { outer_rounds = 10 }; >> >> @@ -337,7 +341,8 @@ do_test (void) >> { >> unsigned int ncpus = CPU_COUNT (&cpuset); >> /* Limit the number to not overload the system. */ >> - outer_threads = (ncpus / 2) / inner_threads ?: 1; >> + outer_threads = MIN ((ncpus / 2) / inner_threads ?: 1, >> + max_outer_threads); > Since this is properly no random state how about just MAX(ncpus, 2)? Works for me.
diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c index 010828920e..4f8cc27b03 100644 --- a/stdlib/tst-arc4random-thread.c +++ b/stdlib/tst-arc4random-thread.c @@ -25,6 +25,7 @@ #include <support/namespace.h> #include <support/support.h> #include <support/xthread.h> +#include <sys/param.h> /* Number of arc4random_buf calls per thread. */ enum { count_per_thread = 2048 }; @@ -35,6 +36,9 @@ enum { inner_threads = 4 }; /* Number of threads launching other threads. */ static int outer_threads = 1; +/* Maximum number of other threads. */ +enum { max_outer_threads = 4 }; + /* Number of launching rounds performed by the outer threads. */ enum { outer_rounds = 10 }; @@ -337,7 +341,8 @@ do_test (void) { unsigned int ncpus = CPU_COUNT (&cpuset); /* Limit the number to not overload the system. */ - outer_threads = (ncpus / 2) / inner_threads ?: 1; + outer_threads = MIN ((ncpus / 2) / inner_threads ?: 1, + max_outer_threads); } printf ("info: outer_threads=%d inner_threads=%d\n", outer_threads,