From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: fweisbec@gmail.com, linux-kernel@vger.kernel.org,
paulus@samba.org, paulmck@linux.vnet.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [RFC PATCH v3 2/5] powerpc: Exception hooks for context tracking subsystem
Date: Mon, 13 May 2013 19:06:31 +1000 [thread overview]
Message-ID: <1368435991.19924.35.camel@pasglop> (raw)
In-Reply-To: <1368434680.2618.33.camel@ThinkPad-T5421>
On Mon, 2013-05-13 at 16:44 +0800, Li Zhong wrote:
> Yes, the above and hash_page() are two C functions for a same exception.
> And the exception hooks enable RCU usage in those C codes. But for asm
> codes, I think we could assume that there would be no RCU usage there,
> so we don't need wrap them in the hooks.
hash_page() won't start a new RCU, at least not in its current incarnation,
the only thing I can see it ever doing would be to take some RCU read locks one
day (it doesn't today).
low_hash_fault() is a different beast. It will typically kill things, thus
involving sending signals etc... RCU might well be involved.
Cheers,
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
paulmck@linux.vnet.ibm.com, fweisbec@gmail.com, paulus@samba.org,
michael@ellerman.id.au
Subject: Re: [RFC PATCH v3 2/5] powerpc: Exception hooks for context tracking subsystem
Date: Mon, 13 May 2013 19:06:31 +1000 [thread overview]
Message-ID: <1368435991.19924.35.camel@pasglop> (raw)
In-Reply-To: <1368434680.2618.33.camel@ThinkPad-T5421>
On Mon, 2013-05-13 at 16:44 +0800, Li Zhong wrote:
> Yes, the above and hash_page() are two C functions for a same exception.
> And the exception hooks enable RCU usage in those C codes. But for asm
> codes, I think we could assume that there would be no RCU usage there,
> so we don't need wrap them in the hooks.
hash_page() won't start a new RCU, at least not in its current incarnation,
the only thing I can see it ever doing would be to take some RCU read locks one
day (it doesn't today).
low_hash_fault() is a different beast. It will typically kill things, thus
involving sending signals etc... RCU might well be involved.
Cheers,
Ben.
next prev parent reply other threads:[~2013-05-13 9:06 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-13 5:21 [RFC PATCH v3 0/5] powerpc: Support context tracking for Power pSeries Li Zhong
2013-05-13 5:21 ` Li Zhong
2013-05-13 5:21 ` [RFC PATCH v3 1/5] powerpc: Syscall hooks for context tracking subsystem Li Zhong
2013-05-13 5:21 ` Li Zhong
2013-05-13 5:21 ` [RFC PATCH v3 2/5] powerpc: Exception " Li Zhong
2013-05-13 5:21 ` Li Zhong
2013-05-13 5:57 ` Benjamin Herrenschmidt
2013-05-13 5:57 ` Benjamin Herrenschmidt
2013-05-13 8:44 ` Li Zhong
2013-05-13 8:44 ` Li Zhong
2013-05-13 9:06 ` Benjamin Herrenschmidt [this message]
2013-05-13 9:06 ` Benjamin Herrenschmidt
2013-05-13 9:46 ` Li Zhong
2013-05-13 9:46 ` Li Zhong
2013-05-13 10:01 ` Benjamin Herrenschmidt
2013-05-13 10:01 ` Benjamin Herrenschmidt
2013-05-13 5:21 ` [RFC PATCH v3 3/5] powerpc: Exit user context on notify resume Li Zhong
2013-05-13 5:21 ` Li Zhong
2013-05-13 5:21 ` [RFC PATCH v3 4/5] powerpc: Use the new schedule_user API on userspace preemption Li Zhong
2013-05-13 5:21 ` Li Zhong
2013-05-13 5:21 ` [RFC PATCH v3 5/5] powerpc: select HAVE_CONTEXT_TRACKING for pSeries Li Zhong
2013-05-13 5:21 ` Li Zhong
2013-05-13 5:51 ` [RFC PATCH v3 0/5] powerpc: Support context tracking for Power pSeries Benjamin Herrenschmidt
2013-05-13 5:51 ` Benjamin Herrenschmidt
2013-05-13 8:03 ` Li Zhong
2013-05-13 8:03 ` Li Zhong
2013-05-13 8:59 ` Benjamin Herrenschmidt
2013-05-13 8:59 ` Benjamin Herrenschmidt
2013-05-13 9:22 ` Li Zhong
2013-05-13 9:22 ` Li Zhong
2013-05-29 21:32 ` Frederic Weisbecker
2013-05-29 21:32 ` Frederic Weisbecker
2013-05-29 21:29 ` Frederic Weisbecker
2013-05-29 21:29 ` Frederic Weisbecker
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