mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Linn Crosetto <linn@hp.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Prarit Bhargava <prarit@redhat.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] x86, irq: get correct available vectors for cpu disable
Date: Wed, 26 Mar 2014 12:55:35 -0600	[thread overview]
Message-ID: <20140326185535.GE24604@oranje.fc.hp.com> (raw)
In-Reply-To: <CAE9FiQUidLDFunEKpVPfSppO1qOzpVPMXW5utd939RdLLei_Fg@mail.gmail.com>

On Wed, Mar 26, 2014 at 10:04:52AM -0700, Yinghai Lu wrote:
> On Wed, Mar 26, 2014 at 9:50 AM, Linn Crosetto <linn@hp.com> wrote:
> > On Tue, Mar 25, 2014 at 05:18:53PM -0700, Yinghai Lu wrote:
> >
> > Just noting that not all bits above first_system_vector are set in the bitmap,
> > so the comment in asm/desc.h and the change log could be misleading:
> >
> > /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
> >
> 
> Do you mean some vector that is neither used by percpu_vector_irq nor
> system_vector
> after first_system_vector ?

Yes, that is the case. In my previous example, first_system_vector is 239, but
test_bit(240, used_vectors) would return unset, though it cannot be used by
percpu vector_irq. If it marked all vectors unusable by percpu vector_irq, then
all bits above first_system_vector would be set.

> Anyway if bit is set in used_vectors, that vector can not be used by
> percpu vector_irq.
> 
> so that statement looks still right.
> 
> Feel free to suggest right comment or changelog.

The following might be more accurate:

/* 
 * The used_vectors BITMAP marks IRQs not managed by percpu vector_irq, below
 * first_system_vector. Vectors above first_system_vector are not managed by
 * percpu vector_irq.
 */

      reply	other threads:[~2014-03-26 18:55 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-28 21:54 Yinghai Lu
2014-01-31 13:14 ` Prarit Bhargava
2014-02-06 19:12 ` Prarit Bhargava
2014-03-25 20:03 ` Linn Crosetto
2014-03-26  0:18   ` Yinghai Lu
2014-03-26 16:50     ` Linn Crosetto
2014-03-26 17:04       ` Yinghai Lu
2014-03-26 18:55         ` Linn Crosetto [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=20140326185535.GE24604@oranje.fc.hp.com \
    --to=linn@hp.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=prarit@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=yinghai@kernel.org \
    /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

Powered by JetHome