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
[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
2010-02-18 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
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 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).