| Message ID | 20240817203659.712085-1-kuba@kernel.org |
|---|---|
| State | Accepted |
| Commit | 555e5531635a7c5dba663d06cea240362624dfde |
| Headers | show |
| Series | [net-next] selftests: net/forwarding: spawn sh inside vrf to speed up ping loop | expand |
On Sat, Aug 17, 2024 at 01:36:59PM -0700, Jakub Kicinski wrote: > Looking at timestamped output of netdev CI reveals that > most of the time in forwarding tests for custom route > hashing is spent on a single case, namely the test which > uses ping (mausezahn does not support flow labels). > > On a non-debug kernel we spend 714 of 730 total test > runtime (97%) on this test case. While having flow label > support in a traffic gen tool / mausezahn would be best, > we can significantly speed up the loop by putting ip vrf exec > outside of the iteration. > > In a test of 1000 pings using a normal loop takes 50 seconds > to finish. While using: > > ip vrf exec $vrf sh -c "$loop-body" > > takes 12 seconds (1/4 of the time). > > Some of the slowness is likely due to our inefficient virtualization > setup, but even on my laptop running "ip link help" 16k times takes > 25-30 seconds, so I think it's worth optimizing even for fastest > setups. > > Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Thanks!
On Sat, Aug 17, 2024 at 01:36:59PM -0700, Jakub Kicinski wrote: > Looking at timestamped output of netdev CI reveals that > most of the time in forwarding tests for custom route > hashing is spent on a single case, namely the test which > uses ping (mausezahn does not support flow labels). > > On a non-debug kernel we spend 714 of 730 total test > runtime (97%) on this test case. While having flow label > support in a traffic gen tool / mausezahn would be best, > we can significantly speed up the loop by putting ip vrf exec > outside of the iteration. > > In a test of 1000 pings using a normal loop takes 50 seconds > to finish. While using: > > ip vrf exec $vrf sh -c "$loop-body" > > takes 12 seconds (1/4 of the time). > > Some of the slowness is likely due to our inefficient virtualization > setup, but even on my laptop running "ip link help" 16k times takes > 25-30 seconds, so I think it's worth optimizing even for fastest > setups. > > Signed-off-by: Jakub Kicinski <kuba@kernel.org> > --- > CC: shuah@kernel.org > CC: idosch@nvidia.com > CC: linux-kselftest@vger.kernel.org > --- > .../selftests/net/forwarding/custom_multipath_hash.sh | 8 ++++---- > .../selftests/net/forwarding/gre_custom_multipath_hash.sh | 8 ++++---- > .../net/forwarding/ip6gre_custom_multipath_hash.sh | 8 ++++---- > 3 files changed, 12 insertions(+), 12 deletions(-) > > diff --git a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh > index 1783c10215e5..7d531f7091e6 100755 > --- a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh > +++ b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh > @@ -224,10 +224,10 @@ send_dst_ipv6() > send_flowlabel() > { > # Generate 16384 echo requests, each with a random flow label. > - for _ in $(seq 1 16384); do > - ip vrf exec v$h1 \ > - $PING6 2001:db8:4::2 -F 0 -c 1 -q >/dev/null 2>&1 > - done > + ip vrf exec v$h1 sh -c \ > + "for _ in {1..16384}; do \ > + $PING6 2001:db8:4::2 -F 0 -c 1 -q >/dev/null 2>&1; \ > + done" > } > > send_src_udp6() > diff --git a/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh > index 9788bd0f6e8b..dda11a4a9450 100755 > --- a/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh > +++ b/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh > @@ -319,10 +319,10 @@ send_dst_ipv6() > send_flowlabel() > { > # Generate 16384 echo requests, each with a random flow label. > - for _ in $(seq 1 16384); do > - ip vrf exec v$h1 \ > - $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1 > - done > + ip vrf exec v$h1 sh -c \ > + "for _ in {1..16384}; do \ > + $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1; \ > + done" > } > > send_src_udp6() > diff --git a/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh > index 2ab9eaaa5532..e28b4a079e52 100755 > --- a/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh > +++ b/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh > @@ -321,10 +321,10 @@ send_dst_ipv6() > send_flowlabel() > { > # Generate 16384 echo requests, each with a random flow label. > - for _ in $(seq 1 16384); do > - ip vrf exec v$h1 \ > - $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1 > - done > + ip vrf exec v$h1 sh -c \ > + "for _ in {1..16384}; do \ > + $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1; \ > + done" > } > > send_src_udp6() > -- > 2.46.0 > Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Sat, 17 Aug 2024 13:36:59 -0700 you wrote: > Looking at timestamped output of netdev CI reveals that > most of the time in forwarding tests for custom route > hashing is spent on a single case, namely the test which > uses ping (mausezahn does not support flow labels). > > On a non-debug kernel we spend 714 of 730 total test > runtime (97%) on this test case. While having flow label > support in a traffic gen tool / mausezahn would be best, > we can significantly speed up the loop by putting ip vrf exec > outside of the iteration. > > [...] Here is the summary with links: - [net-next] selftests: net/forwarding: spawn sh inside vrf to speed up ping loop https://git.kernel.org/netdev/net-next/c/555e5531635a You are awesome, thank you!
diff --git a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh index 1783c10215e5..7d531f7091e6 100755 --- a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh +++ b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh @@ -224,10 +224,10 @@ send_dst_ipv6() send_flowlabel() { # Generate 16384 echo requests, each with a random flow label. - for _ in $(seq 1 16384); do - ip vrf exec v$h1 \ - $PING6 2001:db8:4::2 -F 0 -c 1 -q >/dev/null 2>&1 - done + ip vrf exec v$h1 sh -c \ + "for _ in {1..16384}; do \ + $PING6 2001:db8:4::2 -F 0 -c 1 -q >/dev/null 2>&1; \ + done" } send_src_udp6() diff --git a/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh index 9788bd0f6e8b..dda11a4a9450 100755 --- a/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh +++ b/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh @@ -319,10 +319,10 @@ send_dst_ipv6() send_flowlabel() { # Generate 16384 echo requests, each with a random flow label. - for _ in $(seq 1 16384); do - ip vrf exec v$h1 \ - $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1 - done + ip vrf exec v$h1 sh -c \ + "for _ in {1..16384}; do \ + $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1; \ + done" } send_src_udp6() diff --git a/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh index 2ab9eaaa5532..e28b4a079e52 100755 --- a/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh +++ b/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh @@ -321,10 +321,10 @@ send_dst_ipv6() send_flowlabel() { # Generate 16384 echo requests, each with a random flow label. - for _ in $(seq 1 16384); do - ip vrf exec v$h1 \ - $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1 - done + ip vrf exec v$h1 sh -c \ + "for _ in {1..16384}; do \ + $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1; \ + done" } send_src_udp6()
Looking at timestamped output of netdev CI reveals that most of the time in forwarding tests for custom route hashing is spent on a single case, namely the test which uses ping (mausezahn does not support flow labels). On a non-debug kernel we spend 714 of 730 total test runtime (97%) on this test case. While having flow label support in a traffic gen tool / mausezahn would be best, we can significantly speed up the loop by putting ip vrf exec outside of the iteration. In a test of 1000 pings using a normal loop takes 50 seconds to finish. While using: ip vrf exec $vrf sh -c "$loop-body" takes 12 seconds (1/4 of the time). Some of the slowness is likely due to our inefficient virtualization setup, but even on my laptop running "ip link help" 16k times takes 25-30 seconds, so I think it's worth optimizing even for fastest setups. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- CC: shuah@kernel.org CC: idosch@nvidia.com CC: linux-kselftest@vger.kernel.org --- .../selftests/net/forwarding/custom_multipath_hash.sh | 8 ++++---- .../selftests/net/forwarding/gre_custom_multipath_hash.sh | 8 ++++---- .../net/forwarding/ip6gre_custom_multipath_hash.sh | 8 ++++---- 3 files changed, 12 insertions(+), 12 deletions(-)