From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: xen-devel@lists.xenproject.org, keir@xen.org
Subject: Re: [RFC PATCH v1] Replace tasklets with per-cpu implementation.
Date: Fri, 29 Aug 2014 09:46:49 -0400 [thread overview]
Message-ID: <20140829134649.GC3609@laptop.dumpdata.com> (raw)
In-Reply-To: <53FF3F3A020000780002EB62@mail.emea.novell.com>
On Thu, Aug 28, 2014 at 01:39:54PM +0100, Jan Beulich wrote:
> >>> On 27.08.14 at 19:58, <konrad.wilk@oracle.com> wrote:
> > The 'hvm_do_IRQ_dpci' is the on that is most often scheduled
> > and run. The performance bottleneck comes from the fact that
> > we take the same spinlock three times: tasklet_schedule,
> > when we are about to execute the tasklet, and when we are
> > done executing the tasklet.
>
> Before starting all the work here, did you investigate alternatives
> to this specific use of a tasklet? E.g., it being a softirq one, making
> it have its own softirq?
If I understand you right, you mean implement an tasklet API that
would only been be used by the hvm_do_IRQ_dpci? Its own spinlock,
list, and an seperate tasklet_schedule?
I did think about it a bit a the start, but discarded it since
I figured it would be a no-go upstream - as it is an one-off and seems
hackish.
I can certainly prototype one up and see if it matches the performance
of this implementation if you would like?
next prev parent reply other threads:[~2014-08-29 13:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-27 17:58 [RFC PATCH v1] Replace tasklets with per-cpu implementation Konrad Rzeszutek Wilk
2014-08-27 17:58 ` [RFC PATCH v1 1/5] tasklet: Introduce per-cpu tasklet for softirq Konrad Rzeszutek Wilk
2014-08-27 18:53 ` Andrew Cooper
2014-08-27 19:06 ` Konrad Rzeszutek Wilk
2014-08-28 8:17 ` Jan Beulich
2014-08-27 17:58 ` [RFC PATCH v1 2/5] tasklet: Add cross CPU feeding of per-cpu tasklets Konrad Rzeszutek Wilk
2014-08-27 17:58 ` [RFC PATCH v1 3/5] tasklet: Remove the old-softirq implementation Konrad Rzeszutek Wilk
2014-08-27 17:58 ` [RFC PATCH v1 4/5] tasklet: Introduce per-cpu tasklet for schedule tasklet Konrad Rzeszutek Wilk
2014-08-27 17:58 ` [RFC PATCH v1 5/5] tasklet: Remove the scaffolding Konrad Rzeszutek Wilk
2014-08-28 12:39 ` [RFC PATCH v1] Replace tasklets with per-cpu implementation Jan Beulich
2014-08-29 13:46 ` Konrad Rzeszutek Wilk [this message]
2014-08-29 14:10 ` Jan Beulich
2014-09-02 20:28 ` Konrad Rzeszutek Wilk
2014-09-03 8:03 ` Jan Beulich
2014-09-08 19:01 ` Konrad Rzeszutek Wilk
2014-09-09 9:01 ` Jan Beulich
2014-09-09 14:37 ` Konrad Rzeszutek Wilk
2014-09-09 16:37 ` Jan Beulich
2014-09-10 16:03 ` Konrad Rzeszutek Wilk
2014-09-10 16:25 ` Jan Beulich
2014-09-10 16:35 ` Konrad Rzeszutek Wilk
-- strict thread matches above, loose matches on Subject: below --
2014-08-29 20:58 Arianna Avanzini
2014-09-02 20:10 ` Konrad Rzeszutek Wilk
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