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Groups > linux.kernel > #1604731
| From | Eric Dumazet <eric.dumazet@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t |
| Date | 2017-03-20 17:20 +0100 |
| Message-ID | <tn8ch-7du-9@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <tn5xM-5ik-35@gated-at.bofh.it> <tn5R7-5oQ-7@gated-at.bofh.it> <tn5R7-5oQ-5@gated-at.bofh.it> <tn6WT-6aK-37@gated-at.bofh.it> <tn6WT-6aK-35@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, 2017-03-20 at 07:59 -0700, Eric Dumazet wrote:
> On Mon, 2017-03-20 at 07:51 -0700, Eric Dumazet wrote:
>
> > atomic_cmpxchg() on PowerPC is horribly more expensive because of the
> > added two SYNC instructions.
>
> Although I just saw that refcount was using atomic_cmpxchg_relaxed()
>
> Time to find some documentation (probably missing) or get some specs for
> this thing.
Interesting.
UDP ipv4 xmit path gets a ~25 % improvement on PPC with this patch.
( 20 concurrent netperf -t UDP_STREAM : 2.45 Mpps -> 3.07 Mpps )
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 8471dd116771462d149e1da2807e446b69b74bcc..9f14aebf0ae1f5f366cfff0fbf58c48603916bc7 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -497,14 +497,14 @@ u32 ip_idents_reserve(u32 hash, int segs)
u32 now = (u32)jiffies;
u32 new, delta = 0;
- if (old != now && cmpxchg(p_tstamp, old, now) == old)
+ if (old != now && cmpxchg_relaxed(p_tstamp, old, now) == old)
delta = prandom_u32_max(now - old);
/* Do not use atomic_add_return() as it makes UBSAN unhappy */
do {
old = (u32)atomic_read(p_id);
new = old + delta + segs;
- } while (atomic_cmpxchg(p_id, old, new) != old);
+ } while (atomic_cmpxchg_relaxed(p_id, old, new) != old);
return new - segs;
}
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[PATCH 00/17] net subsystem refcount conversions Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:30 +0100
[PATCH 02/17] net: convert neigh_params.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:30 +0100
[PATCH 10/17] net: convert in_device.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 12/17] net: convert unix_address.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 14/17] net: convert inet_frag_queue.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 01/17] net: convert neighbour.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 11/17] net: convert netpoll_info.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-16 18:00 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Kees Cook <keescook@chromium.org> - 2017-03-16 18:40 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t David Miller <davem@davemloft.net> - 2017-03-16 20:20 +0100
RE: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t "Reshetova, Elena" <elena.reshetova@intel.com> - 2017-03-17 08:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-17 17:20 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Herbert Xu <herbert@gondor.apana.org.au> - 2017-03-18 18:00 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t David Miller <davem@davemloft.net> - 2017-03-19 02:40 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-20 11:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-20 14:30 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-20 14:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-20 16:00 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-20 17:20 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-20 17:40 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-20 16:30 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-20 16:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Kees Cook <keescook@chromium.org> - 2017-03-21 21:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-21 22:30 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t David Miller <davem@davemloft.net> - 2017-03-21 23:40 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Kees Cook <keescook@chromium.org> - 2017-03-22 01:00 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-22 03:10 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-22 13:30 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-22 14:30 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-22 15:40 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-22 16:00 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-22 16:10 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-22 16:30 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-22 18:00 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Kees Cook <keescook@chromium.org> - 2017-03-22 20:10 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-22 14:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Herbert Xu <herbert@gondor.apana.org.au> - 2017-03-20 15:50 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Herbert Xu <herbert@gondor.apana.org.au> - 2017-03-20 14:50 +0100
RE: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t David Laight <David.Laight@ACULAB.COM> - 2017-03-20 15:20 +0100
Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t Peter Zijlstra <peterz@infradead.org> - 2017-03-20 15:30 +0100
RE: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t David Laight <David.Laight@ACULAB.COM> - 2017-03-20 16:10 +0100
[PATCH 05/17] net: convert sk_buff_fclones.fclone_ref from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 15/17] net: convert net.passive from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 16/17] net: convert netlbl_lsm_cache.refcount from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 09/17] net: convert ip_mc_list.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 04/17] net: convert sk_buff.users from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 08/17] net: convert sk_filter.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
Re: [PATCH 08/17] net: convert sk_filter.refcnt from atomic_t to refcount_t Daniel Borkmann <daniel@iogearbox.net> - 2017-03-16 17:10 +0100
RE: [PATCH 08/17] net: convert sk_filter.refcnt from atomic_t to refcount_t "Reshetova, Elena" <elena.reshetova@intel.com> - 2017-03-17 09:20 +0100
[PATCH 17/17] net: convert packet_fanout.sk_ref from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 06/17] net: convert sock.sk_wmem_alloc from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
[PATCH 13/17] net: convert fib_rule.refcnt from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-16 16:40 +0100
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