linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Sudeep Holla <sudeep.holla@arm.com>
Cc: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Marc Zyngier <marc.zyngier@arm.com>,
	Kevin Hilman <khilman@baylibre.com>,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH 2/2] clocksource: arm_arch_timer: set arch_mem_timer cpumask to cpu_possible_mask
Date: Tue, 10 Jul 2018 00:09:11 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.21.1807100008100.1590@nanos.tec.linutronix.de> (raw)
In-Reply-To: <1531151136-18297-2-git-send-email-sudeep.holla@arm.com>

On Mon, 9 Jul 2018, Sudeep Holla wrote:

> Currently, arch_mem_timer cpumask is set to cpu_all_mask which should be
> fine. However, cpu_possible_mask is more accurate and if there are other
> clockevent source in the system which are set to cpu_possible_mask, then
> having cpu_all_mask may result in issue.
> 
> E.g. on a platform with arm,sp804 timer with rating 300 and
> cpu_possible_mask and this arch_mem_timer timer with rating 400 and
> cpu_all_mask, tick_check_preferred may choose both preferred as the
> cpumasks are not equal though they must be.
> 
> This issue was root caused incorrectly initially and a fix was merged as
> commit 1332a9055801 ("tick: Prefer a lower rating device only if it's CPU
> local device").

To avoid that in the future we really should fix the decision logic to mask
out the non possible CPUs from the supplied masks.

Thanks,

	tgkx

  reply	other threads:[~2018-07-09 22:09 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-09 15:45 [PATCH 1/2] Revert "tick: Prefer a lower rating device only if it's CPU local device" Sudeep Holla
2018-07-09 15:45 ` [PATCH 2/2] clocksource: arm_arch_timer: set arch_mem_timer cpumask to cpu_possible_mask Sudeep Holla
2018-07-09 22:09   ` Thomas Gleixner [this message]
2018-07-10 10:29     ` Sudeep Holla
2018-07-10 12:21       ` Thomas Gleixner
2018-07-10 13:25         ` Sudeep Holla
2018-07-10 20:21           ` Thomas Gleixner
2018-07-10 20:16   ` [tip:timers/urgent] clocksource: arm_arch_timer: Set " tip-bot for Sudeep Holla
2018-07-09 18:24 ` [PATCH 1/2] Revert "tick: Prefer a lower rating device only if it's CPU local device" Kevin Hilman
2018-07-09 21:46   ` Martin Blumenstingl
2018-07-10 20:15 ` [tip:timers/urgent] " tip-bot for Sudeep Holla

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=alpine.DEB.2.21.1807100008100.1590@nanos.tec.linutronix.de \
    --to=tglx@linutronix.de \
    --cc=khilman@baylibre.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marc.zyngier@arm.com \
    --cc=mark.rutland@arm.com \
    --cc=martin.blumenstingl@googlemail.com \
    --cc=sudeep.holla@arm.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).