From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Thu, 20 Jun 2013 13:35:51 +0200 Subject: BUG: commit "ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on pre-ARMv6 CPUs" breaks armv5 with CONFIG_PREEMPT In-Reply-To: <20130620111255.GD18536@arm.com> References: <51C2C0B5.8020802@pengutronix.de> <20130620095705.GA18536@arm.com> <51C2D5EF.3040803@pengutronix.de> <20130620102856.GC18536@arm.com> <20130620111255.GD18536@arm.com> Message-ID: <51C2E917.9000708@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/20/2013 01:12 PM, Catalin Marinas wrote: > On Thu, Jun 20, 2013 at 11:28:56AM +0100, Catalin Marinas wrote: >> 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: