From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id AD5E4B7B8A for ; Thu, 30 Jul 2009 14:13:28 +1000 (EST) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 11913DDD1B for ; Thu, 30 Jul 2009 14:13:26 +1000 (EST) From: Kumar Gala To: linuxppc-dev@ozlabs.org Subject: [PATCH] powerpc/mm: Fix SMP issue with MMU context handling code Date: Wed, 29 Jul 2009 23:13:21 -0500 Message-Id: <1248927201-18047-1-git-send-email-galak@kernel.crashing.org> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , In switch_mmu_context() if we call steal_context_smp() to get a context to use we shouldn't fall through and than call steal_context_up(). Doing so can be problematic in that the 'mm' that steal_context_up() ends up using will not get marked dirty in the stale_map[] for other CPUs that might have used that mm. Thus we could end up with stale TLB entries in the other CPUs that can cause all kinda of havoc. Signed-off-by: Kumar Gala Acked-by: Benjamin Herrenschmidt --- arch/powerpc/mm/mmu_context_nohash.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c index 92a1971..b1a727d 100644 --- a/arch/powerpc/mm/mmu_context_nohash.c +++ b/arch/powerpc/mm/mmu_context_nohash.c @@ -217,6 +217,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next) id = steal_context_smp(id); if (id == MMU_NO_CONTEXT) goto again; + goto stolen; } #endif /* CONFIG_SMP */ id = steal_context_up(id); -- 1.6.0.6