From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: Yuriy Kolerov <yuriy.kolerov@synopsys.com>,
"linux-snps-arc@lists.infradead.org"
<linux-snps-arc@lists.infradead.org>
Cc: "Alexey.Brodkin@synopsys.com" <Alexey.Brodkin@synopsys.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH v2 1/2] ARC: SMP: Set the default affinity to the boot cpu
Date: Tue, 13 Dec 2016 09:40:18 -0800 [thread overview]
Message-ID: <450690c2-1c1d-d123-1932-2871ed131828@synopsys.com> (raw)
In-Reply-To: <1481277572-18283-1-git-send-email-yuriy.kolerov@synopsys.com>
Hi Yuriy,
On 12/09/2016 01:59 AM, Yuriy Kolerov wrote:
> By default the kernel sets a value for default affinity which may
> not correspond to the real bitmap of potentially online CPUs. E.g.
> for ARC HS processors with 2 cores the default value of affinity in
> the kernel may be 0xF and it is wrong in this case. This happens
> because init_irq_default_affinity() sets all bits in
> irq_default_affinity variable by default.
>
> It is better to set the default value of affinity to the boot core
> to guarantee that value of irq_default_affinity contains at least
> one valid online CPU during the early stage of booting. It is
> necessary for proper configuration of affinity for common interrupt.
>
> Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
> ---
> arch/arc/kernel/irq.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
> index 538b36a..e53bfd5 100644
> --- a/arch/arc/kernel/irq.c
> +++ b/arch/arc/kernel/irq.c
> @@ -20,6 +20,12 @@
> */
> void __init init_IRQ(void)
> {
> +#ifdef CONFIG_SMP
> + /* Set the default affinity to the boot cpu. */
> + cpumask_clear(irq_default_affinity);
> + cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
> +#endif
> +
> /*
> * process the entire interrupt tree in one go
> * Any external intc will be setup provided DT chains them
For a multi patch series, always include a cover letter. This gives an idea of
over intent of the series.
Also there is no record of what changed between v1 and v2. Reviewers typically
have a short memory span :-)
Also try to include all the reviewers: in this case Marc Z gave very good feedback
and direction for patches.
This is just a general lkml submission best practice !
Now on to the patch itself, I don't like arch code fudging a core genirq global
variable. If at all this needs to be moved into core code - assuming this is the
right thing to do !
Marc , tglx ?
-Vineet
prev parent reply other threads:[~2016-12-13 17:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-09 9:59 [PATCH v2 1/2] ARC: SMP: Set the default affinity to the boot cpu Yuriy Kolerov
2016-12-09 9:59 ` [PATCH v2 2/2] ARCv2: MCIP: Deprecate setting of affinity in Device Tree Yuriy Kolerov
2016-12-13 17:45 ` Vineet Gupta
2016-12-13 17:40 ` Vineet Gupta [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=450690c2-1c1d-d123-1932-2871ed131828@synopsys.com \
--to=vineet.gupta1@synopsys.com \
--cc=Alexey.Brodkin@synopsys.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-snps-arc@lists.infradead.org \
--cc=marc.zyngier@arm.com \
--cc=tglx@linutronix.de \
--cc=yuriy.kolerov@synopsys.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).