From 050eef364ad700590a605a0749f825cab4834b1e Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 24 Aug 2010 09:26:21 +0200 Subject: [S390] fix tlb flushing vs. concurrent /proc accesses The tlb flushing code uses the mm_users field of the mm_struct to decide if each page table entry needs to be flushed individually with IPTE or if a global flush for the mm_struct is sufficient after all page table updates have been done. The comment for mm_users says "How many users with user space?" but the /proc code increases mm_users after it found the process structure by pid without creating a new user process. Which makes mm_users useless for the decision between the two tlb flusing methods. The current code can be confused to not flush tlb entries by a concurrent access to /proc files if e.g. a fork is in progres. The solution for this problem is to make the tlb flushing logic independent from the mm_users field. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/init.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index acc91c75bc94..30eb6d02ddb8 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -74,6 +74,8 @@ void __init paging_init(void) __ctl_load(S390_lowcore.kernel_asce, 13, 13); __raw_local_irq_ssm(ssm_mask); + atomic_set(&init_mm.context.attach_count, 1); + sparse_memory_present_with_active_regions(MAX_NUMNODES); sparse_init(); memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); -- cgit v1.2.1