... On Fri, Jun 13, 2014 at 9:02 PM, Eric W. Biederman <ebied...@xmission.com> wrote: > Rafael Tinoco <rafael.tin...@canonical.com> writes: > >> Okay, >> >> Tests with the same script were done. >> I'm comparing : master + patch vs 3.15.0-rc5 (last sync'ed rcu commit) >> and 3.9 last bisect good. >> >> Same tests were made. I'm comparing the following versions: >> >> 1) master + suggested patch >> 2) 3.15.0-rc5 (last rcu commit in my clone) >> 3) 3.9-rc2 (last bisect good) > > I am having a hard time making sense of your numbers. > > If I have read your email correctly my suggested patch caused: > "ip netns add" numbers to improve > 1x "ip netns exec" to improve some > 2x "ip netns exec" to show no improvement > "ip link add" to show no effect (after the 2x ip netns exec)
- "netns add" are as good as they were before this regression. - "netns exec" are improved but still 50% of the last good bisect commit. - "link add" didn't show difference. > This is interesting in a lot of ways. > - This seems to confirm that the only rcu usage in ip netns add > was switch_task_namespaces. Which is convinient as that rules > out most of the network stack when looking for performance oddities. > > - "ip netns exec" had an expected performance improvement > - "ip netns exec" is still slow (so something odd is still going on) > - "ip link add" appears immaterial to the performance problem. > > It would be interesting to switch the "ip link add" and "ip netns exec" > in your test case to confirm that there is nothing interesting/slow > going on in "ip link add" - will do that. > > Which leaves me with the question what ip "ip netns exec" remains > that is using rcu and is slowing all of this down. - will check this also. > Eric Tks Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
