| Message ID | 20200804123012.378750-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftests/net: skip msg_zerocopy test if we have less than 4 CPUs | expand |
From: Colin King <colin.king@canonical.com> Date: Tue, 4 Aug 2020 13:30:12 +0100 > From: Colin Ian King <colin.king@canonical.com> > > The current test will exit with a failure if it cannot set affinity on > specific CPUs which is problematic when running this on single CPU > systems. Add a check for the number of CPUs and skip the test if > the CPU requirement is not met. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> Willem, please review.
On 8/4/20 5:30 AM, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > The current test will exit with a failure if it cannot set affinity on > specific CPUs which is problematic when running this on single CPU > systems. Add a check for the number of CPUs and skip the test if > the CPU requirement is not met. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > tools/testing/selftests/net/msg_zerocopy.sh | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh > index 825ffec85cea..97bc527e1297 100755 > --- a/tools/testing/selftests/net/msg_zerocopy.sh > +++ b/tools/testing/selftests/net/msg_zerocopy.sh > @@ -21,6 +21,11 @@ readonly DADDR6='fd::2' > > readonly path_sysctl_mem="net.core.optmem_max" > > +if [[ $(nproc) -lt 4 ]]; then > + echo "SKIP: test requires at least 4 CPUs" > + exit 4 > +fi > + > # No arguments: automated test > if [[ "$#" -eq "0" ]]; then > $0 4 tcp -t 1 > Test explicitly uses CPU 2 and 3, right ? nproc could be 500, yet cpu 2 or 3 could be offline # cat /sys/devices/system/cpu/cpu3/online 0 # echo $(nproc) 71
On Wed, Aug 5, 2020 at 2:54 AM Eric Dumazet <eric.dumazet@gmail.com> wrote: > > > > On 8/4/20 5:30 AM, Colin King wrote: > > From: Colin Ian King <colin.king@canonical.com> > > > > The current test will exit with a failure if it cannot set affinity on > > specific CPUs which is problematic when running this on single CPU > > systems. Add a check for the number of CPUs and skip the test if > > the CPU requirement is not met. > > > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > > --- > > tools/testing/selftests/net/msg_zerocopy.sh | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh > > index 825ffec85cea..97bc527e1297 100755 > > --- a/tools/testing/selftests/net/msg_zerocopy.sh > > +++ b/tools/testing/selftests/net/msg_zerocopy.sh > > @@ -21,6 +21,11 @@ readonly DADDR6='fd::2' > > > > readonly path_sysctl_mem="net.core.optmem_max" > > > > +if [[ $(nproc) -lt 4 ]]; then > > + echo "SKIP: test requires at least 4 CPUs" > > + exit 4 > > +fi > > + > > # No arguments: automated test > > if [[ "$#" -eq "0" ]]; then > > $0 4 tcp -t 1 > > > > Test explicitly uses CPU 2 and 3, right ? > > nproc could be 500, yet cpu 2 or 3 could be offline > > # cat /sys/devices/system/cpu/cpu3/online > 0 > # echo $(nproc) > 71 The cpu affinity is only set to bring some stability across runs. The test does not actually verify that a run with zerocopy is some factor faster than without, as that factor is hard to choose across all platforms. As a result the automated run mainly gives code coverage. It's preferable to always run. And on sched_setaffinity failure log a message about possible jitter and continue. I can send that patch, if the approach sounds good.
On 05/08/2020 09:06, Willem de Bruijn wrote: > On Wed, Aug 5, 2020 at 2:54 AM Eric Dumazet <eric.dumazet@gmail.com> wrote: >> >> >> >> On 8/4/20 5:30 AM, Colin King wrote: >>> From: Colin Ian King <colin.king@canonical.com> >>> >>> The current test will exit with a failure if it cannot set affinity on >>> specific CPUs which is problematic when running this on single CPU >>> systems. Add a check for the number of CPUs and skip the test if >>> the CPU requirement is not met. >>> >>> Signed-off-by: Colin Ian King <colin.king@canonical.com> >>> --- >>> tools/testing/selftests/net/msg_zerocopy.sh | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh >>> index 825ffec85cea..97bc527e1297 100755 >>> --- a/tools/testing/selftests/net/msg_zerocopy.sh >>> +++ b/tools/testing/selftests/net/msg_zerocopy.sh >>> @@ -21,6 +21,11 @@ readonly DADDR6='fd::2' >>> >>> readonly path_sysctl_mem="net.core.optmem_max" >>> >>> +if [[ $(nproc) -lt 4 ]]; then >>> + echo "SKIP: test requires at least 4 CPUs" >>> + exit 4 >>> +fi >>> + >>> # No arguments: automated test >>> if [[ "$#" -eq "0" ]]; then >>> $0 4 tcp -t 1 >>> >> >> Test explicitly uses CPU 2 and 3, right ? >> >> nproc could be 500, yet cpu 2 or 3 could be offline >> >> # cat /sys/devices/system/cpu/cpu3/online >> 0 >> # echo $(nproc) >> 71 > > The cpu affinity is only set to bring some stability across runs. > > The test does not actually verify that a run with zerocopy is some > factor faster than without, as that factor is hard to choose across > all platforms. As a result the automated run mainly gives code coverage. > > It's preferable to always run. And on sched_setaffinity failure log a > message about possible jitter and continue. I can send that patch, if > the approach sounds good. > That's sounds preferable to my bad fix for sure :-) Colin
On Wed, Aug 5, 2020 at 10:22 AM Colin Ian King <colin.king@canonical.com> wrote: > > On 05/08/2020 09:06, Willem de Bruijn wrote: > > On Wed, Aug 5, 2020 at 2:54 AM Eric Dumazet <eric.dumazet@gmail.com> wrote: > >> > >> > >> > >> On 8/4/20 5:30 AM, Colin King wrote: > >>> From: Colin Ian King <colin.king@canonical.com> > >>> > >>> The current test will exit with a failure if it cannot set affinity on > >>> specific CPUs which is problematic when running this on single CPU > >>> systems. Add a check for the number of CPUs and skip the test if > >>> the CPU requirement is not met. > >>> > >>> Signed-off-by: Colin Ian King <colin.king@canonical.com> > >>> --- > >>> tools/testing/selftests/net/msg_zerocopy.sh | 5 +++++ > >>> 1 file changed, 5 insertions(+) > >>> > >>> diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh > >>> index 825ffec85cea..97bc527e1297 100755 > >>> --- a/tools/testing/selftests/net/msg_zerocopy.sh > >>> +++ b/tools/testing/selftests/net/msg_zerocopy.sh > >>> @@ -21,6 +21,11 @@ readonly DADDR6='fd::2' > >>> > >>> readonly path_sysctl_mem="net.core.optmem_max" > >>> > >>> +if [[ $(nproc) -lt 4 ]]; then > >>> + echo "SKIP: test requires at least 4 CPUs" > >>> + exit 4 > >>> +fi > >>> + > >>> # No arguments: automated test > >>> if [[ "$#" -eq "0" ]]; then > >>> $0 4 tcp -t 1 > >>> > >> > >> Test explicitly uses CPU 2 and 3, right ? > >> > >> nproc could be 500, yet cpu 2 or 3 could be offline > >> > >> # cat /sys/devices/system/cpu/cpu3/online > >> 0 > >> # echo $(nproc) > >> 71 > > > > The cpu affinity is only set to bring some stability across runs. > > > > The test does not actually verify that a run with zerocopy is some > > factor faster than without, as that factor is hard to choose across > > all platforms. As a result the automated run mainly gives code coverage. > > > > It's preferable to always run. And on sched_setaffinity failure log a > > message about possible jitter and continue. I can send that patch, if > > the approach sounds good. > > > That's sounds preferable to my bad fix for sure :-) Certainly not a bad fix! Thanks for addressing the issue. Alternative approach at http://patchwork.ozlabs.org/project/netdev/patch/20200805084045.1549492-1-willemdebruijn.kernel@gmail.com/
On 05/08/2020 09:44, Willem de Bruijn wrote: > On Wed, Aug 5, 2020 at 10:22 AM Colin Ian King <colin.king@canonical.com> wrote: >> >> On 05/08/2020 09:06, Willem de Bruijn wrote: >>> On Wed, Aug 5, 2020 at 2:54 AM Eric Dumazet <eric.dumazet@gmail.com> wrote: >>>> >>>> >>>> >>>> On 8/4/20 5:30 AM, Colin King wrote: >>>>> From: Colin Ian King <colin.king@canonical.com> >>>>> >>>>> The current test will exit with a failure if it cannot set affinity on >>>>> specific CPUs which is problematic when running this on single CPU >>>>> systems. Add a check for the number of CPUs and skip the test if >>>>> the CPU requirement is not met. >>>>> >>>>> Signed-off-by: Colin Ian King <colin.king@canonical.com> >>>>> --- >>>>> tools/testing/selftests/net/msg_zerocopy.sh | 5 +++++ >>>>> 1 file changed, 5 insertions(+) >>>>> >>>>> diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh >>>>> index 825ffec85cea..97bc527e1297 100755 >>>>> --- a/tools/testing/selftests/net/msg_zerocopy.sh >>>>> +++ b/tools/testing/selftests/net/msg_zerocopy.sh >>>>> @@ -21,6 +21,11 @@ readonly DADDR6='fd::2' >>>>> >>>>> readonly path_sysctl_mem="net.core.optmem_max" >>>>> >>>>> +if [[ $(nproc) -lt 4 ]]; then >>>>> + echo "SKIP: test requires at least 4 CPUs" >>>>> + exit 4 >>>>> +fi >>>>> + >>>>> # No arguments: automated test >>>>> if [[ "$#" -eq "0" ]]; then >>>>> $0 4 tcp -t 1 >>>>> >>>> >>>> Test explicitly uses CPU 2 and 3, right ? >>>> >>>> nproc could be 500, yet cpu 2 or 3 could be offline >>>> >>>> # cat /sys/devices/system/cpu/cpu3/online >>>> 0 >>>> # echo $(nproc) >>>> 71 >>> >>> The cpu affinity is only set to bring some stability across runs. >>> >>> The test does not actually verify that a run with zerocopy is some >>> factor faster than without, as that factor is hard to choose across >>> all platforms. As a result the automated run mainly gives code coverage. >>> >>> It's preferable to always run. And on sched_setaffinity failure log a >>> message about possible jitter and continue. I can send that patch, if >>> the approach sounds good. >>> >> That's sounds preferable to my bad fix for sure :-) > > Certainly not a bad fix! Thanks for addressing the issue. Alternative > approach at > > http://patchwork.ozlabs.org/project/netdev/patch/20200805084045.1549492-1-willemdebruijn.kernel@gmail.com/ > Thanks, you solution is good for my testing requirements Acked-by: Colin Ian King <colin.king@canonical.com>
diff --git a/tools/testing/selftests/net/msg_zerocopy.sh b/tools/testing/selftests/net/msg_zerocopy.sh index 825ffec85cea..97bc527e1297 100755 --- a/tools/testing/selftests/net/msg_zerocopy.sh +++ b/tools/testing/selftests/net/msg_zerocopy.sh @@ -21,6 +21,11 @@ readonly DADDR6='fd::2' readonly path_sysctl_mem="net.core.optmem_max" +if [[ $(nproc) -lt 4 ]]; then + echo "SKIP: test requires at least 4 CPUs" + exit 4 +fi + # No arguments: automated test if [[ "$#" -eq "0" ]]; then $0 4 tcp -t 1