From: Peter Zijlstra <peterz@infradead.org>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
"H. Peter Anvin" <hpa@zytor.com>,
"David S.Miller" <davem@davemloft.net>,
Ingo Molnar <mingo@kernel.org>,
Chandramouli Narayanan <mouli@linux.intel.com>,
Vinodh Gopal <vinodh.gopal@intel.com>,
James Guilford <james.guilford@intel.com>,
Wajdi Feghali <wajdi.k.feghali@intel.com>,
Jussi Kivilinna <jussi.kivilinna@iki.fi>,
linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 6/7] sched: add function nr_running_cpu to expose number of tasks running on cpu
Date: Mon, 14 Jul 2014 18:14:32 +0200 [thread overview]
Message-ID: <20140714161432.GC9918@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1405354214.2970.663.camel@schen9-DESK>
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On Mon, Jul 14, 2014 at 09:10:14AM -0700, Tim Chen wrote:
> On Mon, 2014-07-14 at 12:16 +0200, Peter Zijlstra wrote:
> > On Fri, Jul 11, 2014 at 01:33:04PM -0700, Tim Chen wrote:
> > > This function will help a thread decide if it wants to to do work
> > > that can be delayed, to accumulate more tasks for more efficient
> > > batch processing later.
> > >
> > > However, if no other tasks are running on the cpu, it can take
> > > advantgae of the available cpu cycles to complete the tasks
> > > for immediate processing to minimize delay, otherwise it will yield.
> >
> > Ugh.. and ignore topology and everything else.
> >
> > Yet another scheduler on top of the scheduler.
> >
> > We have the padata muck, also only ever used by crypto.
> > We have the workqueue nonsense, used all over the place
> > And we have btrfs doing their own padata like muck.
> > And I'm sure there's at least one more out there, just because.
> >
> > Why do we want yet another thing?
> >
> > I'm inclined to go NAK and get people to reduce the amount of async
> > queueing and processing crap.
>
> The mult-buffer class of crypto algorithms is by nature
> asynchronous. The algorithm gathers several crypto jobs, and
> put the buffer from each job in a data lane of the SIMD register.
> This allows for parallel processing and increases throughput.
> The gathering of the crypto jobs is an async process and
> queuing is necessary for this class of algorithm.
How is that related to me saying we've got too much of this crap
already?
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next prev parent reply other threads:[~2014-07-14 16:14 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1405074379.git.tim.c.chen@linux.intel.com>
2014-07-11 20:32 ` [PATCH v4 0/7] crypto: SHA1 multibuffer implementation Tim Chen
2014-07-11 20:32 ` [PATCH v4 1/7] crypto: SHA1 multibuffer crypto hash infrastructure Tim Chen
2014-07-11 20:32 ` [PATCH v4 2/7] crypto: SHA1 multibuffer algorithm data structures Tim Chen
2014-07-11 20:32 ` [PATCH v4 3/7] crypto: SHA1 multibuffer submit and flush routines for AVX2 Tim Chen
2014-07-11 20:32 ` [PATCH v4 4/7] crypto: SHA1 multibuffer crypto computation (x8 AVX2) Tim Chen
2014-07-11 20:33 ` [PATCH v4 5/7] crypto: SHA1 multibuffer scheduler Tim Chen
2014-07-11 20:33 ` [PATCH v4 6/7] sched: add function nr_running_cpu to expose number of tasks running on cpu Tim Chen
2014-07-12 9:25 ` Kirill Tkhai
2014-07-14 17:51 ` Tim Chen
2014-07-12 14:21 ` Tadeusz Struk
2014-07-14 23:51 ` Tim Chen
2014-07-14 10:16 ` Peter Zijlstra
2014-07-14 16:10 ` Tim Chen
2014-07-14 16:14 ` Peter Zijlstra [this message]
2014-07-14 17:05 ` Tim Chen
2014-07-14 18:17 ` Peter Zijlstra
2014-07-14 19:08 ` Tim Chen
2014-07-14 19:15 ` Peter Zijlstra
2014-07-14 19:50 ` Tim Chen
2014-07-15 9:50 ` Peter Zijlstra
2014-07-15 12:07 ` Peter Zijlstra
2014-07-15 12:59 ` Thomas Gleixner
2014-07-15 14:45 ` Mike Galbraith
2014-07-15 14:53 ` Peter Zijlstra
2014-07-15 18:06 ` Mike Galbraith
2014-07-15 19:03 ` Peter Zijlstra
2014-07-15 19:24 ` Mike Galbraith
2014-07-15 18:41 ` Tim Chen
2014-07-15 20:46 ` Thomas Gleixner
2014-07-15 18:40 ` Tim Chen
2014-07-15 18:40 ` Tim Chen
2014-07-15 13:36 ` Peter Zijlstra
2014-07-15 15:21 ` Tejun Heo
2014-07-15 16:37 ` Peter Zijlstra
2014-07-11 20:33 ` [PATCH v4 7/7] crypto: SHA1 multibuffer - flush the jobs early if cpu becomes idle Tim Chen
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