| Message ID | 1434417013.27504.161.camel@edumazet-glaptop2.roam.corp.google.com |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
Eric Dumazet <eric.dumazet@gmail.com> wrote: > From: Eric Dumazet <edumazet@google.com> > > Let's force a 16 bytes alignment on xt_counter percpu allocations, > so that bytes and packets sit in same cache line. > > xt_counter being exported to user space, we cannot add __align(16) on > the structure itself. Sorry, I was away. Looks great. Acked-by: Florian Westphal <fw@strlen.de> -- 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
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Mon, 15 Jun 2015 18:10:13 -0700 > From: Eric Dumazet <edumazet@google.com> > > Let's force a 16 bytes alignment on xt_counter percpu allocations, > so that bytes and packets sit in same cache line. > > xt_counter being exported to user space, we cannot add __align(16) on > the structure itself. > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Florian Westphal <fw@strlen.de> Pablo, I assume you will take this. -- 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, Jun 18, 2015 at 03:43:26AM -0700, David Miller wrote: > From: Eric Dumazet <eric.dumazet@gmail.com> > Date: Mon, 15 Jun 2015 18:10:13 -0700 > > > From: Eric Dumazet <edumazet@google.com> > > > > Let's force a 16 bytes alignment on xt_counter percpu allocations, > > so that bytes and packets sit in same cache line. > > > > xt_counter being exported to user space, we cannot add __align(16) on > > the structure itself. > > > > Signed-off-by: Eric Dumazet <edumazet@google.com> > > Cc: Florian Westphal <fw@strlen.de> > > Pablo, I assume you will take this. Yes, I'll prepare another pull request for you along today. -- 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 Wed, Jun 17, 2015 at 07:08:15PM +0200, Florian Westphal wrote: > Eric Dumazet <eric.dumazet@gmail.com> wrote: > > From: Eric Dumazet <edumazet@google.com> > > > > Let's force a 16 bytes alignment on xt_counter percpu allocations, > > so that bytes and packets sit in same cache line. > > > > xt_counter being exported to user space, we cannot add __align(16) on > > the structure itself. > > Sorry, I was away. Looks great. > > Acked-by: Florian Westphal <fw@strlen.de> Applied, thanks Eric and Florian ! -- 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/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 95693c4cebdda473a2f3e427dcc2511e83bf7405..1c97a2204379e14676ee33f0b15c5174b7afe680 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -356,7 +356,8 @@ static inline unsigned long ifname_compare_aligned(const char *_a, * so nothing needs to be done there. * * xt_percpu_counter_alloc returns the address of the percpu - * counter, or 0 on !SMP. + * counter, or 0 on !SMP. We force an alignment of 16 bytes + * so that bytes/packets share a common cache line. * * Hence caller must use IS_ERR_VALUE to check for error, this * allows us to return 0 for single core systems without forcing @@ -365,7 +366,8 @@ static inline unsigned long ifname_compare_aligned(const char *_a, static inline u64 xt_percpu_counter_alloc(void) { if (nr_cpu_ids > 1) { - void __percpu *res = alloc_percpu(struct xt_counters); + void __percpu *res = __alloc_percpu(sizeof(struct xt_counters), + sizeof(struct xt_counters)); if (res == NULL) return (u64) -ENOMEM;