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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2007-04-10 17:09:37 +1000
committerPaul Mackerras <paulus@samba.org>2007-04-13 04:09:38 +1000
commita741e67969577163a4cfc78d7fd2753219087ef1 (patch)
treebac4162aaf15367e896429afa60465e201c9204c /arch/powerpc/kernel/smp.c
parente4ee3891db35aa9a069bb403c2a66a8fbfa274d6 (diff)
[POWERPC] Make tlb flush batch use lazy MMU mode
The current tlb flush code on powerpc 64 bits has a subtle race since we lost the page table lock due to the possible faulting in of new PTEs after a previous one has been removed but before the corresponding hash entry has been evicted, which can leads to all sort of fatal problems. This patch reworks the batch code completely. It doesn't use the mmu_gather stuff anymore. Instead, we use the lazy mmu hooks that were added by the paravirt code. They have the nice property that the enter/leave lazy mmu mode pair is always fully contained by the PTE lock for a given range of PTEs. Thus we can guarantee that all batches are flushed on a given CPU before it drops that lock. We also generalize batching for any PTE update that require a flush. Batching is now enabled on a CPU by arch_enter_lazy_mmu_mode() and disabled by arch_leave_lazy_mmu_mode(). The code epects that this is always contained within a PTE lock section so no preemption can happen and no PTE insertion in that range from another CPU. When batching is enabled on a CPU, every PTE updates that need a hash flush will use the batch for that flush. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
-rw-r--r--arch/powerpc/kernel/smp.c4
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 924d692bc8f..d8e503b2e1a 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -428,10 +428,6 @@ void generic_mach_cpu_die(void)
smp_wmb();
while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
cpu_relax();
-
-#ifdef CONFIG_PPC64
- flush_tlb_pending();
-#endif
cpu_set(cpu, cpu_online_map);
local_irq_enable();
}