From: "H. Peter Anvin" <hpa@zytor.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Yinghai Lu <yinghai@kernel.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Suresh Siddha <suresh.b.siddha@intel.com>,
linux-kernel@vger.kernel.org,
Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: [PATCH 0/8] tip related: radix tree for spareseirq and logical flat clean up
Date: Fri, 12 Feb 2010 19:49:11 -0800 [thread overview]
Message-ID: <4B762137.4050604@zytor.com> (raw)
In-Reply-To: <m1zl3dre9e.fsf@fess.ebiederm.org>
On 02/12/2010 07:44 PM, Eric W. Biederman wrote:
>
> Thanks for keeping this work alive.
>
Indeed. I am hoping to put this in tip tomorrow or so.
> I just skimmed through do_IRQ and I happened to notice that
> we have an unnecessary inefficiency that using a radix tree for
> irq_to_desc will magnify.
>
> handle_irq should take an struct irq_desc * instead of a unsigned int irq.
>
> and the per cpu vector_irq array should become a per cpu vector_desc array.
>
> As soon as irq_to_desc is more than &irq_desc[irq] this saves us work
> and cache line misses at the cost of a simple code cleanup.
Good catch. I haven't looked through the details yet, but I presume
this can be done on top of this changeset?
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2010-02-13 3:51 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-13 2:49 [PATCH 0/8] tip related: radix tree for spareseirq and logical flat clean up Yinghai Lu
2010-02-13 2:49 ` [PATCH 1/8] irq: remove not need bootmem code Yinghai Lu
2010-02-13 2:49 ` [PATCH 2/8] radix: move radix init early Yinghai Lu
2010-02-13 2:49 ` [PATCH 3/8] sparseirq: change irq_desc_ptrs to static Yinghai Lu
2010-02-13 2:49 ` [PATCH 4/8] sparseirq: use radix_tree instead of ptrs array Yinghai Lu
2010-02-13 2:49 ` [PATCH 5/8] x86: remove arch_probe_nr_irqs Yinghai Lu
2010-02-13 2:49 ` [PATCH 6/8] use nr_cpus= to set nr_cpu_ids early Yinghai Lu
2010-02-13 2:49 ` [PATCH 7/8] x86: use num_processors for possible cpus Yinghai Lu
2010-02-13 2:49 ` [PATCH 8/8] x86: make 32bit apic flat to physflat switch like 64bit Yinghai Lu
2010-02-13 3:44 ` [PATCH 0/8] tip related: radix tree for spareseirq and logical flat clean up Eric W. Biederman
2010-02-13 3:49 ` H. Peter Anvin [this message]
2010-02-13 4:17 ` Eric W. Biederman
2010-02-13 22:12 ` Jeremy Fitzhardinge
2010-02-13 22:26 ` Eric W. Biederman
2010-02-13 9:54 ` Yinghai Lu
2010-02-13 11:39 ` Eric W. Biederman
2010-02-13 12:04 ` Eric W. Biederman
2010-02-13 22:40 ` Yinghai Lu
2010-02-13 23:14 ` Eric W. Biederman
2010-02-13 23:59 ` Yinghai Lu
2010-02-14 0:30 ` Eric W. Biederman
2010-02-14 0:49 ` Yinghai Lu
2010-02-18 2:49 ` [PATCH 1/3] xen: Remove unnecessary arch specific xen irq functions Yinghai Lu
2010-02-19 1:36 ` [tip:x86/irq] " tip-bot for Eric W. Biederman
[not found] ` <4B7CA9A1.3020806@kernel.org>
2010-02-18 2:49 ` [PATCH 0/3] radix tree spareirq addon cleanup Yinghai Lu
2010-02-18 2:50 ` [PATCH 2/3] x86: use vector_desc instead of vector_irq Yinghai Lu
2010-02-18 17:22 ` Eric W. Biederman
2010-02-23 6:39 ` [PATCH -v3 1/2] " Yinghai Lu
2010-02-23 6:44 ` [PATCH -v2 2/2] genericirq: change ack/mask in irq_chip to take irq_desc instead of irq Yinghai Lu
2010-02-24 21:36 ` Eric W. Biederman
2010-02-24 22:07 ` Yinghai Lu
2010-02-25 0:22 ` Stephen Rothwell
2010-03-02 14:58 ` Thomas Gleixner
2010-03-03 8:49 ` Yinghai Lu
2010-03-03 10:26 ` Thomas Gleixner
[not found] ` <4B84F013.9040708@kernel.org>
2010-02-24 9:26 ` [PATCH -v3 " Yinghai Lu
2010-02-24 9:27 ` [PATCH -v4 1/2] x86: use vector_desc instead of vector_irq Yinghai Lu
2010-02-18 2:50 ` [RFC PATCH 3/3] genericirq: change ack/mask in irq_chip to take irq_desc in addition to irq Yinghai Lu
2010-02-18 17:04 ` Eric W. Biederman
2010-02-18 17:13 ` H. Peter Anvin
2010-02-18 19:51 ` Yinghai Lu
2010-02-13 12:26 ` [PATCH 0/8] tip related: radix tree for spareseirq and logical flat clean up Eric W. Biederman
2010-02-13 22:36 ` Yinghai Lu
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=4B762137.4050604@zytor.com \
--to=hpa@zytor.com \
--cc=akpm@linux-foundation.org \
--cc=ebiederm@xmission.com \
--cc=jeremy@goop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=suresh.b.siddha@intel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.