From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Paul Mackerras <paulus@au1.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"H. Peter Anvin" <hpa@zytor.com>,
James Hogan <james.hogan@imgtec.com>,
"James E.J. Bottomley" <jejb@parisc-linux.org>,
Helge Deller <deller@gmx.de>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC GIT PULL] softirq: Consolidation and stack overrun fix
Date: Mon, 23 Sep 2013 14:40:34 +1000 [thread overview]
Message-ID: <1379911234.6625.7.camel@pasglop> (raw)
In-Reply-To: <1379799901.24090.6.camel@pasglop>
On Sun, 2013-09-22 at 07:45 +1000, Benjamin Herrenschmidt wrote:
> What I *can* do that would help I suppose would be to switch to the irq
> stack before irq_enter/exit which would at least mean that softirq would
> run from the top of the irq stack which is better than the current
> situation.
>
> I'm fact I'll whip up a quick fix see if that might be enough of a band
> aid for RHEL7.
OK I've done that, it seems to work so far. Heads up guys: i386 and sparc
at least seem to need the same treatment. I haven't looked at others except
ARM which doesn't seem to have irq stacks to begin with.
We can also instead apply Fred's series to put back in the switch to the
softirq stack since this is actually a regression , but then, arguably,
making sure irq_exit() is called off the irq stack is better and means
we do one instead of two stack switches.
Fred: Maybe revert partially under an arch #define/Kconfig so we can get
the best of both worlds ?
Cheers,
Ben.
next prev parent reply other threads:[~2013-09-23 4:41 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-19 19:51 [RFC GIT PULL] softirq: Consolidation and stack overrun fix Frederic Weisbecker
2013-09-19 19:51 ` [PATCH 1/3] irq: Consolidate do_softirq() arch overriden implementations Frederic Weisbecker
2013-09-19 19:51 ` [PATCH 2/3] irq: Execute softirq on its own stack on irq exit Frederic Weisbecker
2013-09-19 19:51 ` [PATCH 3/3] irq: Comment on the use of inline stack for ksoftirqd Frederic Weisbecker
2013-09-20 0:02 ` [RFC GIT PULL] softirq: Consolidation and stack overrun fix Linus Torvalds
2013-09-20 1:53 ` Benjamin Herrenschmidt
2013-09-20 11:03 ` Thomas Gleixner
2013-09-20 11:11 ` Peter Zijlstra
2013-09-21 0:55 ` Benjamin Herrenschmidt
2013-09-20 16:26 ` Frederic Weisbecker
2013-09-20 17:30 ` Thomas Gleixner
2013-09-20 18:37 ` Frederic Weisbecker
2013-09-20 22:14 ` Linus Torvalds
2013-09-21 7:47 ` Ingo Molnar
2013-09-21 18:58 ` Frederic Weisbecker
2013-09-21 21:45 ` Benjamin Herrenschmidt
2013-09-21 23:27 ` Frederic Weisbecker
2013-09-22 2:01 ` H. Peter Anvin
2013-09-22 4:39 ` Benjamin Herrenschmidt
2013-09-22 4:41 ` Benjamin Herrenschmidt
2013-09-22 16:24 ` Peter Zijlstra
2013-09-22 17:47 ` H. Peter Anvin
2013-09-22 22:00 ` Benjamin Herrenschmidt
2013-09-22 21:56 ` Benjamin Herrenschmidt
2013-09-22 22:22 ` Linus Torvalds
2013-09-22 22:38 ` Benjamin Herrenschmidt
2013-09-23 4:35 ` [PATCH] powerpc/irq: Run softirqs off the top of the irq stack Benjamin Herrenschmidt
2013-09-23 7:56 ` Stephen Rothwell
2013-09-23 10:13 ` Benjamin Herrenschmidt
2013-09-23 16:47 ` Linus Torvalds
2013-09-23 20:51 ` Benjamin Herrenschmidt
2013-09-24 5:42 ` [PATCH v2] " Benjamin Herrenschmidt
2013-09-23 17:59 ` [RFC GIT PULL] softirq: Consolidation and stack overrun fix Chris Metcalf
2013-09-23 20:57 ` Benjamin Herrenschmidt
2013-09-24 19:27 ` Chris Metcalf
2013-09-24 20:58 ` Benjamin Herrenschmidt
2013-09-24 0:10 ` Benjamin Herrenschmidt
2013-09-24 1:19 ` Linus Torvalds
2013-09-24 1:52 ` Benjamin Herrenschmidt
2013-09-24 8:04 ` Peter Zijlstra
2013-09-24 8:16 ` Benjamin Herrenschmidt
2013-09-24 8:21 ` Peter Zijlstra
2013-09-24 9:31 ` Benjamin Herrenschmidt
2013-09-23 4:40 ` Benjamin Herrenschmidt [this message]
2013-09-23 5:01 ` David Miller
2013-09-24 2:44 ` Frederic Weisbecker
2013-09-24 4:42 ` Benjamin Herrenschmidt
2013-09-24 13:56 ` Frederic Weisbecker
2013-09-24 20:55 ` Benjamin Herrenschmidt
2013-09-25 8:46 ` Frederic Weisbecker
2013-09-21 0:52 ` Benjamin Herrenschmidt
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