From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Paul Mackerras <paulus@au1.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
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>,
Anton Blanchard <anton@au1.ibm.com>
Subject: Re: [RFC GIT PULL] softirq: Consolidation and stack overrun fix
Date: Tue, 24 Sep 2013 19:31:39 +1000 [thread overview]
Message-ID: <1380015099.5443.43.camel@pasglop> (raw)
In-Reply-To: <20130924082128.GJ9326@twins.programming.kicks-ass.net>
On Tue, 2013-09-24 at 10:21 +0200, Peter Zijlstra wrote:
> > I don't see how that relates to the above though...
>
> It was a comment on the increase of per-cpu usage in generic code.
Oh I see. Ok, but some things are intrinsically per-task so if you use
per-cpu in that case you end up context switching, at least that's what
Linus alluded to. It would be nice if such construct we design so that
we still access them via the task struct on arch where such accesses are
cheap.
I think if/when we get rid of using r13 for our arch specific "PACA", it
becomes easy for me to experiment with using it for either per-cpu or
current and do some measurements. It also means I can easily switch "the
other way" if I need to. I'll dig into that, it will probably take some
time before I sanitize our code enough anyway.
Cheers,
Ben.
next prev parent reply other threads:[~2013-09-24 9:32 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 [this message]
2013-09-23 4:40 ` Benjamin Herrenschmidt
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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