From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] Add a text_poke syscall
Date: Wed, 20 Nov 2013 13:00:11 -0800 [thread overview]
Message-ID: <528D22DB.1020208@zytor.com> (raw)
In-Reply-To: <87mwkzvvck.fsf@tassilo.jf.intel.com>
On 11/20/2013 09:25 AM, Andi Kleen wrote:
> "H. Peter Anvin" <hpa@zytor.com> writes:
>>
>> We're talking user space here, which has different requirement (COW,
>> memory protection, ...) which means it is not really the same code. You
>> can't take a page fault while patching the kernel.
>
> The syscall pins the page, then it calls the kernel code.
> There are no page faults during patching.
>
But you don't need to pin anything if you just do it in userspace.
Again, it is particularly poignant for large batched operations.
-hpa
next prev parent reply other threads:[~2013-11-20 21:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-19 0:27 [PATCH] Add a text_poke syscall Andi Kleen
2013-11-19 2:32 ` Andy Lutomirski
2013-11-19 20:16 ` Andi Kleen
2013-11-21 10:02 ` Jiri Kosina
2013-11-19 5:23 ` H. Peter Anvin
2013-11-19 18:49 ` Andi Kleen
2013-11-20 16:42 ` H. Peter Anvin
2013-11-20 17:25 ` Andi Kleen
2013-11-20 18:30 ` H. Peter Anvin
2013-11-20 21:00 ` H. Peter Anvin [this message]
2013-11-21 12:49 ` Steven Rostedt
2013-11-19 6:49 ` Ingo Molnar
2013-11-19 19:10 ` Andi Kleen
2013-11-21 13:07 ` Steven Rostedt
2013-11-22 3:26 ` Andi Kleen
2013-11-21 18:26 ` Oleg Nesterov
2013-11-22 3:29 ` Andi Kleen
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