linux-kernel - Re: vmalloc_sync_all(), 64bit kernel, patches 9c48f1c629ecfa114850c03f875c6691003214de, a79e53d85683c6dd9f99c90511028adc2043031f

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Message-ID: <m2wqx4fcm7.fsf@firstfloor.org>
Date:	Thu, 29 Nov 2012 11:11:28 -0800
From:	Andi Kleen <andi@...stfloor.org>
To:	Prasad Koya <prasad.koya@...il.com>
Cc:	dzickus@...hat.com, aarcange@...hat.com,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: vmalloc_sync_all(), 64bit kernel, patches 9c48f1c629ecfa114850c03f875c6691003214de, a79e53d85683c6dd9f99c90511028adc2043031f

Prasad Koya <prasad.koya@...il.com> writes:

> Hi
>
> Before going into crashkernel, nmi_shootdown_cpus() calls
> register_die_notifier(), which calls vmalloc_sync_all(). I'm seeing
> lockup in sync_global_pgds() (init_64.c). From 3.2 and up,
> register_die_notifier() is replaced with register_nmi_handler() (patch
> 9c48f1c629ecfa114850c03f875c6691003214de), which doesn't call
> vmalloc_sync_all(). Is it ok to skip vmalloc_sync_all() in this path?

Yes it's ok for this case. vmalloc_sync_all is only needed when the
notifier is in freshly loaded module code.

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only
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