Re: [systemd-devel] [PATCH] sysctl.d: default to fq_codel, fight bufferbloat
On Thu, 16.10.14 14:05, Michal Schmidt (mschm...@redhat.com) wrote: Quoting from Jon Corbet's report of Stephen Hemminger's talk at Linux Plumbers Conference 2014 (https://lwn.net/Articles/616241/): [...] So Stephen encouraged everybody to run a command like: sysctl -w net.core.default_qdisc=fq_codel That will cause fq_codel to be used for all future connections (up to the next reboot). Unfortunately, the default queuing discipline cannot be changed, since it will certainly disturb some user's workload somewhere. So kernel developers know the best default is fq_codel, but won't change to it in the kernel itself. Instead they expect distros to do it. Let's have the recommended default in systemd. Judging by the article this sounds like a good thing to do, and systemd seems to be an OK place for this change if the kernel folks don't want to make it. Hence, go ahead, but make sure to add this to NEWS with an explanation that downstream distros should be aware of the change, and possibly revert it, if they don't want to go down this route. Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] sysctl.d: default to fq_codel, fight bufferbloat
Am 20.10.2014 16:48 schrieb Lennart Poettering lenn...@poettering.net: On Thu, 16.10.14 14:05, Michal Schmidt (mschm...@redhat.com) wrote: Quoting from Jon Corbet's report of Stephen Hemminger's talk at Linux Plumbers Conference 2014 (https://lwn.net/Articles/616241/): [...] So Stephen encouraged everybody to run a command like: sysctl -w net.core.default_qdisc=fq_codel That will cause fq_codel to be used for all future connections (up to the next reboot). Unfortunately, the default queuing discipline cannot be changed, since it will certainly disturb some user's workload somewhere. So kernel developers know the best default is fq_codel, but won't change to it in the kernel itself. Instead they expect distros to do it. Let's have the recommended default in systemd. Judging by the article this sounds like a good thing to do, and systemd seems to be an OK place for this change if the kernel folks don't want to make it. Hence, go ahead, but make sure to add this to NEWS with an explanation that downstream distros should be aware of the change, and possibly revert it, if they don't want to go down this route. So what about: kernel.kptr_restrict=1 fs.protected_symlinks=1 fs.protected_hardlinks=1 Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] sysctl.d: default to fq_codel, fight bufferbloat
On Mon, 20.10.14 19:49, Thomas Meyer (tho...@m3y3r.de) wrote: Am 20.10.2014 16:48 schrieb Lennart Poettering lenn...@poettering.net: On Thu, 16.10.14 14:05, Michal Schmidt (mschm...@redhat.com) wrote: Quoting from Jon Corbet's report of Stephen Hemminger's talk at Linux Plumbers Conference 2014 (https://lwn.net/Articles/616241/): [...] So Stephen encouraged everybody to run a command like: sysctl -w net.core.default_qdisc=fq_codel That will cause fq_codel to be used for all future connections (up to the next reboot). Unfortunately, the default queuing discipline cannot be changed, since it will certainly disturb some user's workload somewhere. So kernel developers know the best default is fq_codel, but won't change to it in the kernel itself. Instead they expect distros to do it. Let's have the recommended default in systemd. Judging by the article this sounds like a good thing to do, and systemd seems to be an OK place for this change if the kernel folks don't want to make it. Hence, go ahead, but make sure to add this to NEWS with an explanation that downstream distros should be aware of the change, and possibly revert it, if they don't want to go down this route. So what about: kernel.kptr_restrict=1 fs.protected_symlinks=1 fs.protected_hardlinks=1 The latter two we already ship as defaults. The kptr thing, what's the story on that? Is there a clear opinion that this is something to enable by default, but which isn't set from upstream because of fear of compat probs? Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] [PATCH] sysctl.d: default to fq_codel, fight bufferbloat
Quoting from Jon Corbet's report of Stephen Hemminger's talk at Linux Plumbers Conference 2014 (https://lwn.net/Articles/616241/): [...] So Stephen encouraged everybody to run a command like: sysctl -w net.core.default_qdisc=fq_codel That will cause fq_codel to be used for all future connections (up to the next reboot). Unfortunately, the default queuing discipline cannot be changed, since it will certainly disturb some user's workload somewhere. So kernel developers know the best default is fq_codel, but won't change to it in the kernel itself. Instead they expect distros to do it. Let's have the recommended default in systemd. --- sysctl.d/50-default.conf | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sysctl.d/50-default.conf b/sysctl.d/50-default.conf index 8fc9ab7..f189233 100644 --- a/sysctl.d/50-default.conf +++ b/sysctl.d/50-default.conf @@ -25,6 +25,9 @@ net.ipv4.conf.all.accept_source_route = 0 net.ipv4.conf.default.promote_secondaries = 1 net.ipv4.conf.all.promote_secondaries = 1 +# Fair Queue CoDel packet scheduler to fight bufferbloat +net.core.default_qdisc = fq_codel + # Enable hard and soft link protection fs.protected_hardlinks = 1 fs.protected_symlinks = 1 -- 2.1.0 ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] sysctl.d: default to fq_codel, fight bufferbloat
On Thu, Oct 16, 2014 at 02:05:47PM +0200, Michal Schmidt wrote: Quoting from Jon Corbet's report of Stephen Hemminger's talk at Linux Plumbers Conference 2014 (https://lwn.net/Articles/616241/): [...] So Stephen encouraged everybody to run a command like: sysctl -w net.core.default_qdisc=fq_codel That will cause fq_codel to be used for all future connections (up to the next reboot). Unfortunately, the default queuing discipline cannot be changed, since it will certainly disturb some user's workload somewhere. So kernel developers know the best default is fq_codel, but won't change to it in the kernel itself. Instead they expect distros to do it. Let's have the recommended default in systemd. I had the exact same thought. I'm +1. Zbyszek ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
