From: Borislav Petkov <bp@alien8.de>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [PATCH 0/5] Support negative number of CPUs
Date: Wed, 1 Apr 2015 11:37:10 +0200 [thread overview]
Message-ID: <20150401093709.GA18403@pd.tnic> (raw)
In-Reply-To: <1427844036-1325-1-git-send-email-fweisbec@gmail.com>
On Wed, Apr 01, 2015 at 01:20:31AM +0200, Frederic Weisbecker wrote:
> Support for machines without any CPU at all was brought 3 years ago
> by Paul (https://lkml.org/lkml/2012/3/31/131). The goal was to reduce
> the complexity of programming on modern computing.
>
> Now meeting the simplicity beyond that of sequential programming had a
> cost: such hardware configuration found a user base but didn't meet much
> success among HPC users.
>
> So we have now a new challenge to solve: keep the beyond-sequential
> programming simplicity while providing a highly parallel processing that
> still scale.
>
> This patchset proposes a solution. The support for negative number of
> CPUs is able to help scale computing up to O(-NR_CPUS). The more you have
> CPUs the higher you scale, to the point that software execution should
> complete before you start writing that software (assuming you have around
> -1024 CPUs). And programming gets even more simple because you have lesser
> CPUs to handle.
>
> Now keep in mind this patchset is only a draft. Not build tested and
> I don't have the hardware yet.
>
> Frederic Weisbecker (5):
> cpu: Infrastructure for negative cpu handling
> smp: IPI handling for negative CPU
> cpumask: Basic negative number of CPUs handling
> init: Support negative CPUs boot and halt code
> x86: Support reverse execution
I have been wanting a feature like that since forever! Thanks for doing
this Frederic.
I'd like to propose an addition to that feature: execute whole programs
backwards. But should be easily doable with patch 5 in the series.
Acked-by: Borislav Petkov <bp@alienski.de>
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
prev parent reply other threads:[~2015-04-01 9:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-31 23:20 [PATCH 0/5] Support negative number of CPUs Frederic Weisbecker
2015-03-31 23:20 ` [PATCH 1/5] cpu: Infrastructure for negative cpu handling Frederic Weisbecker
2015-03-31 23:20 ` [PATCH 2/5] smp: IPI handling for negative CPU Frederic Weisbecker
2015-03-31 23:20 ` [PATCH 3/5] cpumask: Basic negative number of CPUs handling Frederic Weisbecker
2015-03-31 23:20 ` [PATCH 4/5] init: Support negative CPUs boot and halt code Frederic Weisbecker
2015-03-31 23:20 ` [PATCH 5/5] x86: Support reverse execution Frederic Weisbecker
2015-04-01 7:35 ` [PATCH 0/5] Support negative number of CPUs Paul E. McKenney
2015-04-01 9:37 ` Borislav Petkov [this message]
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