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

From: Andi Kleen
Date: Thu Nov 29 2012 - 14:11:20 EST


Prasad Koya <prasad.koya@xxxxxxxxx> 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@xxxxxxxxxxxxxxx -- Speaking for myself only
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/