BUG: commit "ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on pre-ARMv6 CPUs" breaks armv5 with CONFIG_PREEMPT
From: mkl@pengutronix.de (Marc Kleine-Budde)
Date: 2013-06-20 11:35:51
On 06/20/2013 01:12 PM, Catalin Marinas wrote:
On Thu, Jun 20, 2013 at 11:28:56AM +0100, Catalin Marinas wrote:quoted
We may need to place the preempt disable/enable at a higher level in the scheduler. My theory is that we have a context switch from prev to next. We get preempted just before finish_arch_post_lock_switch(), so the MMU hasn't been switched yet. The new switch during preemption happens to a thread with the same next mm, so the scheduler no longer switch_mm() and the TIF_SWITCH_MM isn't set for the new thread. I'll come back with another patch shortly.Here's another attempt (as before, only compile-tested):
booting kernel from /image zImage: concatenated oftree detected booting Linux kernel with devicetree ...dead... Does every process have a "mm"? Even Kernel threads? Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 259 bytes Desc: OpenPGP digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20130620/26b07f5f/attachment.sig>