| Message ID | 1447371693-25143-5-git-send-email-hannes@cmpxchg.org |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Johannes Weiner <hannes@cmpxchg.org> Date: Thu, 12 Nov 2015 18:41:23 -0500 > When a cgroup currently breaches its socket memory limit, it enters > memory pressure mode for itself and its *ancestors*. This throttles > transmission in unrelated sibling and cousin subtrees that have > nothing to do with the breached limit. > > On the contrary, breaching a limit should make that group and its > *children* enter memory pressure mode. But this happens already, > albeit lazily: if an ancestor limit is breached, siblings will enter > memory pressure on their own once the next packet arrives for them. > > So no additional hierarchy code is needed. Remove the bogus stuff. > > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Nov 12, 2015 at 06:41:23PM -0500, Johannes Weiner wrote: > When a cgroup currently breaches its socket memory limit, it enters > memory pressure mode for itself and its *ancestors*. This throttles > transmission in unrelated sibling and cousin subtrees that have > nothing to do with the breached limit. > > On the contrary, breaching a limit should make that group and its > *children* enter memory pressure mode. But this happens already, > albeit lazily: if an ancestor limit is breached, siblings will enter > memory pressure on their own once the next packet arrives for them. Hmm, we still call sk_prot->enter_memory_pressure, which might hurt a workload in the root cgroup AFAICS. Strange. You fix it in patch 8 though. > > So no additional hierarchy code is needed. Remove the bogus stuff. > > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/sock.h b/include/net/sock.h index c4b33c9..6fc9147 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1152,14 +1152,8 @@ static inline void sk_leave_memory_pressure(struct sock *sk) if (*memory_pressure) *memory_pressure = 0; - if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { - struct cg_proto *cg_proto = sk->sk_cgrp; - struct proto *prot = sk->sk_prot; - - for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) - cg_proto->memory_pressure = 0; - } - + if (mem_cgroup_sockets_enabled && sk->sk_cgrp) + sk->sk_cgrp->memory_pressure = 0; } static inline void sk_enter_memory_pressure(struct sock *sk) @@ -1167,13 +1161,8 @@ static inline void sk_enter_memory_pressure(struct sock *sk) if (!sk->sk_prot->enter_memory_pressure) return; - if (mem_cgroup_sockets_enabled && sk->sk_cgrp) { - struct cg_proto *cg_proto = sk->sk_cgrp; - struct proto *prot = sk->sk_prot; - - for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto)) - cg_proto->memory_pressure = 1; - } + if (mem_cgroup_sockets_enabled && sk->sk_cgrp) + sk->sk_cgrp->memory_pressure = 1; sk->sk_prot->enter_memory_pressure(sk); }
When a cgroup currently breaches its socket memory limit, it enters memory pressure mode for itself and its *ancestors*. This throttles transmission in unrelated sibling and cousin subtrees that have nothing to do with the breached limit. On the contrary, breaching a limit should make that group and its *children* enter memory pressure mode. But this happens already, albeit lazily: if an ancestor limit is breached, siblings will enter memory pressure on their own once the next packet arrives for them. So no additional hierarchy code is needed. Remove the bogus stuff. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> --- include/net/sock.h | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-)