From: Simon Horman <horms@verge.net.au>
To: Julian Anastasov <ja@ssi.bg>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
netfilter@vger.kernel.org, lvs-devel@vger.kernel.org,
Hans Schillstrom <hans@schillstrom.com>
Subject: Re: [PATCH 03/18] ipvs: zero percpu stats
Date: Thu, 10 Mar 2011 10:34:42 +0900 [thread overview]
Message-ID: <20110310013442.GD3028@verge.net.au> (raw)
In-Reply-To: <alpine.LFD.2.00.1103061218470.1879@ja.ssi.bg>
On Sun, Mar 06, 2011 at 02:18:35PM +0200, Julian Anastasov wrote:
[ snip ]
> Zero the new percpu stats because we copy from there.
> Use the stats spin lock to synchronize the percpu zeroing with
> the percpu reading, both in user context and not in a hot path.
>
> Signed-off-by: Julian Anastasov <ja@ssi.bg>
Eric, do you have any thoughts on this?
It seems clean to me.
> ---
>
> diff -urp lvs-test-2.6-8a80c79/linux/net/netfilter/ipvs/ip_vs_ctl.c linux/net/netfilter/ipvs/ip_vs_ctl.c
> --- lvs-test-2.6-8a80c79/linux/net/netfilter/ipvs/ip_vs_ctl.c 2011-03-06 13:39:59.000000000 +0200
> +++ linux/net/netfilter/ipvs/ip_vs_ctl.c 2011-03-06 13:44:56.108275455 +0200
> @@ -713,8 +713,25 @@ static void ip_vs_trash_cleanup(struct n
> static void
> ip_vs_zero_stats(struct ip_vs_stats *stats)
> {
> + struct ip_vs_cpu_stats *cpustats = stats->cpustats;
> + int i;
> +
> spin_lock_bh(&stats->lock);
>
> + for_each_possible_cpu(i) {
> + struct ip_vs_cpu_stats *u = per_cpu_ptr(cpustats, i);
> + unsigned int start;
> +
> + /* Do not pretend to be writer, it is enough to
> + * sync with writers that modify the u64 counters
> + * because under stats->lock there are no other readers
> + */
> + do {
> + start = u64_stats_fetch_begin(&u->syncp);
> + memset(&u->ustats, 0, sizeof(u->ustats));
> + } while (u64_stats_fetch_retry(&u->syncp, start));
> + }
> +
> memset(&stats->ustats, 0, sizeof(stats->ustats));
> ip_vs_zero_estimator(stats);
>
> @@ -2015,16 +2032,19 @@ static int ip_vs_stats_percpu_show(struc
> seq_printf(seq,
> "CPU Conns Packets Packets Bytes Bytes\n");
>
> + /* Use spin lock early to synchronize with percpu zeroing */
> + spin_lock_bh(&tot_stats->lock);
> +
> for_each_possible_cpu(i) {
> struct ip_vs_cpu_stats *u = per_cpu_ptr(cpustats, i);
> unsigned int start;
> __u64 inbytes, outbytes;
>
> do {
> - start = u64_stats_fetch_begin_bh(&u->syncp);
> + start = u64_stats_fetch_begin(&u->syncp);
> inbytes = u->ustats.inbytes;
> outbytes = u->ustats.outbytes;
> - } while (u64_stats_fetch_retry_bh(&u->syncp, start));
> + } while (u64_stats_fetch_retry(&u->syncp, start));
>
> seq_printf(seq, "%3X %8X %8X %8X %16LX %16LX\n",
> i, u->ustats.conns, u->ustats.inpkts,
> @@ -2032,7 +2052,6 @@ static int ip_vs_stats_percpu_show(struc
> (__u64)outbytes);
> }
>
> - spin_lock_bh(&tot_stats->lock);
> seq_printf(seq, " ~ %8X %8X %8X %16LX %16LX\n\n",
> tot_stats->ustats.conns, tot_stats->ustats.inpkts,
> tot_stats->ustats.outpkts,
>
next prev parent reply other threads:[~2011-03-10 1:34 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-05 23:45 [patch v2 ] IPVS: Conditionally include sysctl code Simon Horman
2011-03-05 23:45 ` [PATCH 01/18] ipvs: move struct netns_ipvs Simon Horman
2011-03-05 23:45 ` [PATCH 02/18] ipvs: reorganize tot_stats Simon Horman
2011-03-05 23:45 ` [PATCH 03/18] ipvs: zero percpu stats Simon Horman
2011-03-06 9:06 ` Eric Dumazet
2011-03-06 12:18 ` Julian Anastasov
2011-03-10 1:34 ` Simon Horman [this message]
2011-03-10 2:53 ` David Miller
2011-03-10 4:27 ` Simon Horman
2011-03-13 10:57 ` Eric Dumazet
2011-03-13 23:29 ` Julian Anastasov
2011-03-05 23:45 ` [PATCH 04/18] ipvs: remove unused seqcount stats Simon Horman
2011-03-05 23:45 ` [PATCH 05/18] IPVS: Add ip_vs_route_me_harder() Simon Horman
2011-03-05 23:45 ` [PATCH 06/18] IPVS: Add sysctl_snat_reroute() Simon Horman
2011-03-05 23:45 ` [PATCH 07/18] IPVS: Add sysctl_nat_icmp_send() Simon Horman
2011-03-05 23:45 ` [PATCH 08/18] IPVS: Add {sysctl_sync_threshold,period}() Simon Horman
2011-03-05 23:45 ` [PATCH 09/18] IPVS: Add sysctl_sync_ver() Simon Horman
2011-03-05 23:45 ` [PATCH 10/18] IPVS: Add sysctl_expire_nodest_conn() Simon Horman
2011-03-05 23:45 ` [PATCH 11/18] IPVS: Add expire_quiescent_template() Simon Horman
2011-03-05 23:45 ` [PATCH 12/18] IPVS: Conditinally use sysctl_lblc{r}_expiration Simon Horman
2011-03-05 23:45 ` [PATCH 13/18] IPVS: ip_vs_todrop() becomes a noop when CONFIG_SYSCTL is undefined Simon Horman
2011-03-05 23:45 ` [PATCH 14/18] IPVS: Conditional ip_vs_conntrack_enabled() Simon Horman
2011-03-05 23:45 ` [PATCH 15/18] IPVS: Minimise ip_vs_leave when CONFIG_SYSCTL is undefined Simon Horman
2011-03-05 23:45 ` [PATCH 16/18] IPVS: Conditionally define and use ip_vs_lblc{r}_table Simon Horman
2011-03-05 23:45 ` [PATCH 17/18] IPVS: Add __ip_vs_control_{init,cleanup}_sysctl() Simon Horman
2011-03-05 23:46 ` [PATCH 18/18] IPVS: Conditionally include sysctl members of struct netns_ipvs Simon Horman
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