From: Peter Zijlstra <peterz@infradead.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
Andy Lutomirski <luto@amacapital.net>
Subject: Re: Lazy FPU restoration / moving kernel_fpu_end() to context switch
Date: Mon, 18 Jun 2018 11:44:47 +0200 [thread overview]
Message-ID: <20180618094447.GG2458@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHmME9qr4PzsGKK2r2sGoCty_Yum_3UqUdL76CPOAOq18K+a4A@mail.gmail.com>
On Fri, Jun 15, 2018 at 10:30:46PM +0200, Jason A. Donenfeld wrote:
> On Fri, Jun 15, 2018 at 9:34 PM Peter Zijlstra <peterz@infradead.org> wrote:
> > Didn't we recently do a bunch of crypto patches to help with this?
> >
> > I think they had the pattern:
> >
> > kernel_fpu_begin();
> > for (units-of-work) {
> > do_unit_of_work();
> > if (need_resched()) {
> > kernel_fpu_end();
> > cond_resched();
> > kernel_fpu_begin();
> > }
> > }
> > kernel_fpu_end();
>
> Right, so that's the thing -- this is an optimization easily available
> to individual crypto primitives. But I'm interested in applying this
> kind of optimization to an entire queue of, say, tiny packets, where
> each packet is processed individually. Or, to a cryptographic
> construction, where several different primitives are used, such that
> it'd be meaningful not to have to get the performance hit of
> end()begin() in between each and everyone of them.
I'm confused.. how does the above not apply to your situation?
next prev parent reply other threads:[~2018-06-18 9:44 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-15 13:11 Lazy FPU restoration / moving kernel_fpu_end() to context switch Jason A. Donenfeld
2018-06-15 16:25 ` Thomas Gleixner
2018-06-15 18:33 ` Brian Gerst
2018-06-15 19:34 ` Peter Zijlstra
2018-06-15 20:30 ` Jason A. Donenfeld
2018-06-18 9:44 ` Peter Zijlstra [this message]
2018-06-18 15:25 ` Jason A. Donenfeld
2018-06-15 18:31 ` Andy Lutomirski
2018-06-15 18:40 ` Rik van Riel
2018-06-15 18:41 ` Dave Hansen
2018-06-15 18:49 ` Andy Lutomirski
2018-06-15 18:48 ` Dave Hansen
2018-06-15 18:53 ` Andy Lutomirski
2018-06-15 20:27 ` Jason A. Donenfeld
2018-06-15 20:48 ` Jason A. Donenfeld
2018-06-19 11:43 ` David Laight
2018-06-19 13:08 ` Thomas Gleixner
2018-06-15 20:33 ` Jason A. Donenfeld
2018-06-15 20:42 ` Dave Hansen
2018-06-15 20:52 ` Andy Lutomirski
2018-06-15 20:56 ` Rik van Riel
2018-07-11 16:28 ` Sebastian Andrzej Siewior
2018-07-11 20:10 ` Rik van Riel
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