From: Stephen Hemminger <stephen@networkplumber.org>
To: "Mattias Rönnblom" <hofors@lysator.liu.se>
Cc: "Ferruh Yigit" <ferruh.yigit@amd.com>,
"John W. Linville" <linville@tuxdriver.com>,
"Thomas Monjalon" <thomas@monjalon.net>,
dev@dpdk.org, "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>,
"Morten Brørup" <mb@smartsharesystems.com>
Subject: Re: [RFC v2] net/af_packet: make stats reset reliable
Date: Thu, 2 May 2024 14:46:34 -0700 [thread overview]
Message-ID: <20240502144634.1808da56@hermes.local> (raw)
In-Reply-To: <e3e6929b-f9b9-439d-8e50-faf161992154@lysator.liu.se>
On Thu, 2 May 2024 23:26:31 +0200
Mattias Rönnblom <hofors@lysator.liu.se> wrote:
> >
> > You are confusing atomic usage for thread safety, with the necessity
> > of compiler barriers.
> >
>
> Are you suggesting that program-level C11 atomic stores risk being
> delayed, indefinitely? I could only find a draft version of the
> standard, but there 7.17.3 says "Implementations should make atomic
> stores visible to atomic loads within a reasonable amount of time."
>
> An atomic relaxed store will be much cheaper than a compiler barrier.
There is a confusion between language designers C11 and system implementer and
CPU design. The language people confuse compiler with hardware in standards.
Because of course the compiler knows all (not).
Read the extended discussion on memory models in Linux kernel documentation.
https://www.kernel.org/doc/html/latest/core-api/wrappers/memory-barriers.html
next prev parent reply other threads:[~2024-05-02 21:46 UTC|newest]
Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-25 17:46 [RFC] " Ferruh Yigit
2024-04-26 11:33 ` Morten Brørup
2024-04-26 13:37 ` Ferruh Yigit
2024-04-26 14:56 ` Morten Brørup
2024-04-28 15:42 ` Mattias Rönnblom
2024-04-26 14:38 ` [RFC v2] " Ferruh Yigit
2024-04-26 14:47 ` Morten Brørup
2024-04-28 15:11 ` Mattias Rönnblom
2024-05-01 16:19 ` Ferruh Yigit
2024-05-02 5:51 ` Mattias Rönnblom
2024-05-02 14:22 ` Ferruh Yigit
2024-05-02 15:59 ` Stephen Hemminger
2024-05-02 18:20 ` Ferruh Yigit
2024-05-02 17:37 ` Mattias Rönnblom
2024-05-02 18:26 ` Stephen Hemminger
2024-05-02 21:26 ` Mattias Rönnblom
2024-05-02 21:46 ` Stephen Hemminger [this message]
2024-05-07 7:23 ` Mattias Rönnblom
2024-05-07 13:49 ` Ferruh Yigit
2024-05-07 14:51 ` Stephen Hemminger
2024-05-07 16:00 ` Morten Brørup
2024-05-07 16:54 ` Ferruh Yigit
2024-05-07 18:47 ` Stephen Hemminger
2024-05-08 7:48 ` Mattias Rönnblom
2024-05-08 6:28 ` Mattias Rönnblom
2024-05-08 6:25 ` Mattias Rönnblom
2024-05-07 19:19 ` Morten Brørup
2024-05-08 6:34 ` Mattias Rönnblom
2024-05-08 7:10 ` Morten Brørup
2024-05-08 7:23 ` Mattias Rönnblom
2024-04-26 21:28 ` [RFC] " Patrick Robb
2024-05-03 15:45 ` [RFC v3] " Ferruh Yigit
2024-05-03 22:00 ` Stephen Hemminger
2024-05-07 13:48 ` Ferruh Yigit
2024-05-07 14:52 ` Stephen Hemminger
2024-05-07 17:27 ` Ferruh Yigit
2024-05-08 7:19 ` Mattias Rönnblom
2024-05-08 15:23 ` Stephen Hemminger
2024-05-08 19:48 ` Ferruh Yigit
2024-05-08 20:54 ` Stephen Hemminger
2024-05-09 7:43 ` Morten Brørup
2024-05-09 9:29 ` Bruce Richardson
2024-05-09 11:37 ` Morten Brørup
2024-05-09 14:19 ` Morten Brørup
2024-05-10 4:56 ` Stephen Hemminger
2024-05-10 9:14 ` Morten Brørup
2024-05-07 15:27 ` Morten Brørup
2024-05-07 17:40 ` Ferruh Yigit
2024-05-10 5:01 ` [RFC 0/3] generic sw counters Stephen Hemminger
2024-05-10 5:01 ` [RFC 1/3] ethdev: add internal helper of SW driver statistics Stephen Hemminger
2024-05-10 5:01 ` [RFC 2/3] net/af_packet: use SW stats helper Stephen Hemminger
2024-05-10 5:01 ` [RFC 3/3] net/tap: use generic SW stats Stephen Hemminger
2024-05-10 17:29 ` [RFC 0/3] generic sw counters Morten Brørup
2024-05-10 19:30 ` Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 0/7] generic SW counters Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 1/7] eal: generic 64 bit counter Stephen Hemminger
2024-05-13 19:36 ` Morten Brørup
2024-05-13 18:52 ` [RFC v2 2/7] ethdev: add internal helper of SW driver statistics Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 3/7] net/af_packet: use SW stats helper Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 4/7] net/tap: use generic SW stats Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 5/7] net/pcap: " Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 6/7] net/af_xdp: " Stephen Hemminger
2024-05-13 18:52 ` [RFC v2 7/7] net/ring: " Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 0/7] Generic SW counters Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 1/7] eal: generic 64 bit counter Stephen Hemminger
2024-05-15 9:30 ` Morten Brørup
2024-05-15 15:03 ` Stephen Hemminger
2024-05-15 16:18 ` Morten Brørup
2024-05-14 15:35 ` [PATCH v3 2/7] ethdev: add internal helper of SW driver statistics Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 3/7] net/af_packet: use SW stats helper Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 4/7] net/af_xdp: use generic SW stats Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 5/7] net/pcap: " Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 6/7] net/ring: " Stephen Hemminger
2024-05-14 15:35 ` [PATCH v3 7/7] net/tap: " Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 0/8] Generic 64 bit counters for SW PMD's Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 1/8] eal: generic 64 bit counter Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 2/8] ethdev: add common counters for statistics Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 3/8] net/af_packet: use generic SW stats Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 4/8] net/af_xdp: " Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 5/8] net/pcap: " Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 6/8] net/ring: " Stephen Hemminger
2024-05-15 23:40 ` [PATCH v4 7/8] net/tap: " Stephen Hemminger
2024-05-15 23:41 ` [PATCH v4 8/8] net/null: " Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 0/9] Generic 64 bit counters Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 1/9] eal: generic 64 bit counter Stephen Hemminger
2024-05-16 18:22 ` Wathsala Wathawana Vithanage
2024-05-16 21:42 ` Stephen Hemminger
2024-05-17 2:39 ` Honnappa Nagarahalli
2024-05-17 3:29 ` Stephen Hemminger
2024-05-17 4:39 ` Honnappa Nagarahalli
2024-05-16 15:40 ` [PATCH v5 2/9] ethdev: add common counters for statistics Stephen Hemminger
2024-05-16 18:30 ` Wathsala Wathawana Vithanage
2024-05-17 0:19 ` Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 3/9] net/af_packet: use generic SW stats Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 4/9] net/af_xdp: " Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 5/9] net/pcap: " Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 6/9] test/pmd_ring: initialize mbufs Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 7/9] net/ring: use generic SW stats Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 8/9] net/tap: " Stephen Hemminger
2024-05-16 15:40 ` [PATCH v5 9/9] net/null: " Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 0/9] Generic 64 bit counters for SW drivers Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 1/9] eal: generic 64 bit counter Stephen Hemminger
2024-05-17 2:45 ` Honnappa Nagarahalli
2024-05-17 3:30 ` Stephen Hemminger
2024-05-17 4:26 ` Honnappa Nagarahalli
2024-05-17 6:44 ` Morten Brørup
2024-05-17 15:05 ` Stephen Hemminger
2024-05-17 16:18 ` Stephen Hemminger
2024-05-18 14:00 ` Morten Brørup
2024-05-17 15:07 ` Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 2/9] ethdev: add common counters for statistics Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 3/9] net/af_packet: use generic SW stats Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 4/9] net/af_xdp: " Stephen Hemminger
2024-05-17 13:34 ` Loftus, Ciara
2024-05-17 14:54 ` Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 5/9] net/pcap: " Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 6/9] test/pmd_ring: initialize mbufs Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 7/9] net/ring: use generic SW stats Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 8/9] net/tap: " Stephen Hemminger
2024-05-17 0:12 ` [PATCH v6 9/9] net/null: " Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 0/9] Use weak atomic operations for SW PMD counters Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 1/9] eal: generic 64 bit counter Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 2/9] ethdev: add common counters for statistics Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 3/9] net/af_packet: use generic SW stats Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 4/9] net/af_xdp: " Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 5/9] net/pcap: " Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 6/9] test/pmd_ring: initialize mbufs Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 7/9] net/ring: use generic SW stats Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 8/9] net/tap: " Stephen Hemminger
2024-05-17 17:35 ` [PATCH v7 9/9] net/null: " Stephen Hemminger
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