From: Linus Torvalds <torvalds@linux-foundation.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>,
x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
jesse.brandeburg@intel.com
Subject: Re: [PATCH] Prevent nested interrupts when the IRQ stack is near overflowing v2
Date: Thu, 25 Mar 2010 09:17:13 -0700 (PDT) [thread overview]
Message-ID: <alpine.LFD.2.00.1003250915410.3721@i5.linux-foundation.org> (raw)
In-Reply-To: <alpine.LFD.2.00.1003250842240.3721@i5.linux-foundation.org>
On Thu, 25 Mar 2010, Linus Torvalds wrote:
>
> NOTE! Historically, the "fast" handlers also had a much faster irq
> response because they didn't do that whole MASK/ACK/END thing. So they'd
> just keep the CPU interrupts disabled, and ACK at the end, and I think
> we've even used AUTOEIO so that they didn't need any ACK at all, and we
> never touched the interrupt controller itself for them.
Btw, it was even more extreme than that. The fast irq handlers got a
totally separate kernel entry point, and wouldn't save all registers, only
the compiler-clobbered ones. Which is why they then had no "struct
pt_regs" etc.
And yes, it really mattered. Then later we got so bloated that it wasn't
much of an issue - and just made everything more complicated.
Linus
next prev parent reply other threads:[~2010-03-25 16:22 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-24 19:02 [PATCH] Prevent nested interrupts when the IRQ stack is near overflowing v2 Andi Kleen
2010-03-24 20:42 ` Thomas Gleixner
2010-03-24 23:08 ` Thomas Gleixner
2010-03-25 0:36 ` Andi Kleen
2010-03-25 1:46 ` Thomas Gleixner
2010-03-25 9:37 ` Andi Kleen
2010-03-25 11:09 ` Thomas Gleixner
2010-03-25 12:11 ` Andi Kleen
2010-03-25 13:17 ` Thomas Gleixner
2010-03-25 13:32 ` Andi Kleen
2010-03-25 14:16 ` Thomas Gleixner
2010-03-25 15:38 ` Andi Kleen
2010-03-25 16:06 ` Alan Cox
2010-03-25 16:13 ` Linus Torvalds
2010-03-25 16:17 ` Linus Torvalds [this message]
2010-03-25 16:27 ` Ingo Molnar
2010-03-25 16:33 ` Ingo Molnar
2010-03-25 18:27 ` Andi Kleen
2010-03-26 4:55 ` Eric W. Biederman
2010-03-25 16:52 ` Thomas Gleixner
2010-03-25 17:47 ` Peter Zijlstra
2010-03-25 18:01 ` Linus Torvalds
2010-03-25 18:21 ` Peter Zijlstra
2010-03-25 18:23 ` Peter Zijlstra
2010-03-25 18:44 ` Andi Kleen
2010-03-25 19:01 ` Ingo Molnar
2010-03-25 18:29 ` Ingo Molnar
2010-03-25 19:10 ` Linus Torvalds
2010-03-25 19:42 ` David Miller
2010-03-25 20:40 ` Linus Torvalds
2010-03-26 3:33 ` David Miller
2010-03-25 20:51 ` Ingo Molnar
2010-03-25 20:53 ` Linus Torvalds
2010-03-26 6:10 ` Andi Kleen
2010-03-25 10:50 ` Alan Cox
2010-03-25 11:16 ` Thomas Gleixner
2010-03-25 11:59 ` Alan Cox
2010-03-25 12:00 ` Andi Kleen
2010-03-25 11:57 ` Andi Kleen
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.LFD.2.00.1003250915410.3721@i5.linux-foundation.org \
--to=torvalds@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=jesse.brandeburg@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=x86@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