From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Mattias Rönnblom" <hofors@lysator.liu.se>,
"Stephen Hemminger" <stephen@networkplumber.org>
Cc: <dev@dpdk.org>, "Bruce Richardson" <bruce.richardson@intel.com>,
"Konstantin Ananyev" <konstantin.v.ananyev@yandex.ru>,
"Jan Viktorin" <viktorin@rehivetech.com>,
"Ruifeng Wang" <ruifeng.wang@arm.com>,
"David Christensen" <drc@linux.vnet.ibm.com>,
"Stanislaw Kardach" <kda@semihalf.com>
Subject: RE: [RFC v2] non-temporal memcpy
Date: Wed, 10 Aug 2022 14:18:45 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D87253@smartserver.smartshare.dk> (raw)
In-Reply-To: <4baabd37-ead4-d98b-0e61-01c6ecd23191@lysator.liu.se>
> From: Mattias Rönnblom [mailto:hofors@lysator.liu.se]
> Sent: Wednesday, 10 August 2022 13.56
>
> On 2022-08-09 17:26, Stephen Hemminger wrote:
[...]
>
> Alignment seems like a non-issue to me. A NT-store memcpy() can be made
> free of alignment requirements, incurring only a very slight cost for
> the always-aligned case (who has their data always 16-byte aligned
> anyways?).
>
> The memory barrier required on x86 seems like a bigger issue.
>
> > Maybe rte_non_cache_copy()?
> >
>
> rte_memcpy_nt_weakly_ordered(), or rte_memcpy_nt_weak(). And a
> rte_memcpy_nt() with the sfence is place, which the user hopefully will
> find first? I don't know. I would prefer not having the weak variant at
> all.
>
> Accepting weak memory ordering (i.e., no sfence) could also be one of
> the flags, assuming rte_memcpy_nt() would have a flags parameter.
> Default is safe (=memcpy() semantics), but potentially slower.
Excellent idea!
>
> > Want to avoid the naive user just doing s/memcpy/rte_memcpy_nt/ and
> expect
> > everything to work.
next prev parent reply other threads:[~2022-08-10 12:18 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-19 15:26 Morten Brørup
2022-07-19 18:00 ` David Christensen
2022-07-19 18:41 ` Morten Brørup
2022-07-19 18:51 ` Stanisław Kardach
2022-07-19 22:15 ` Morten Brørup
2022-07-21 23:19 ` Konstantin Ananyev
2022-07-22 10:44 ` Morten Brørup
2022-07-24 13:35 ` Konstantin Ananyev
2022-07-24 22:18 ` Morten Brørup
2022-07-29 10:00 ` Konstantin Ananyev
2022-07-29 10:46 ` Morten Brørup
2022-07-29 11:50 ` Konstantin Ananyev
2022-07-29 17:17 ` Morten Brørup
2022-07-29 22:00 ` Konstantin Ananyev
2022-07-30 9:51 ` Morten Brørup
2022-08-02 9:05 ` Konstantin Ananyev
2022-07-29 12:13 ` Konstantin Ananyev
2022-07-29 16:05 ` Stephen Hemminger
2022-07-29 17:29 ` Morten Brørup
2022-08-07 20:40 ` Mattias Rönnblom
2022-08-09 9:24 ` Morten Brørup
2022-08-09 11:53 ` Mattias Rönnblom
2022-10-09 16:16 ` Morten Brørup
2022-07-29 18:13 ` Morten Brørup
2022-07-29 19:49 ` Konstantin Ananyev
2022-07-29 20:26 ` Morten Brørup
2022-07-29 21:34 ` Konstantin Ananyev
2022-08-07 20:20 ` Mattias Rönnblom
2022-08-09 9:34 ` Morten Brørup
2022-08-09 11:56 ` Mattias Rönnblom
2022-08-10 21:05 ` Honnappa Nagarahalli
2022-08-11 11:50 ` Mattias Rönnblom
2022-08-11 16:26 ` Honnappa Nagarahalli
2022-07-25 1:17 ` Honnappa Nagarahalli
2022-07-27 10:26 ` Morten Brørup
2022-07-27 17:37 ` Honnappa Nagarahalli
2022-07-27 18:49 ` Morten Brørup
2022-07-27 19:12 ` Stephen Hemminger
2022-07-28 9:00 ` Morten Brørup
2022-07-27 19:52 ` Honnappa Nagarahalli
2022-07-27 22:02 ` Stanisław Kardach
2022-07-28 10:51 ` Morten Brørup
2022-07-29 9:21 ` Konstantin Ananyev
2022-08-07 20:25 ` Mattias Rönnblom
2022-08-09 9:46 ` Morten Brørup
2022-08-09 12:05 ` Mattias Rönnblom
2022-08-09 15:00 ` Morten Brørup
2022-08-10 11:47 ` Mattias Rönnblom
2022-08-09 15:26 ` Stephen Hemminger
2022-08-09 17:24 ` Morten Brørup
2022-08-10 11:59 ` Mattias Rönnblom
2022-08-10 12:12 ` Morten Brørup
2022-08-10 11:55 ` Mattias Rönnblom
2022-08-10 12:18 ` Morten Brørup [this message]
2022-08-10 21:20 ` Honnappa Nagarahalli
2022-08-11 11:53 ` Mattias Rönnblom
2022-08-11 22:24 ` Honnappa Nagarahalli
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