[PATCH] x86: UV cleanup

From: Cliff Wickman
Date: Thu Jan 29 2009 - 14:37:28 EST




From: Cliff Wickman <cpw@xxxxxxx>

This patch tweaks a couple things:

- uv_flush_tlb_others()
the WARN_ON(!in_atomic()); fails if CONFIG_PREEMPT is not enabled

The #ifdef may not be the right fix. The fix is probably in the
in_atomic macro, but I'm not sure what in_atomic() should return
if CONFIG_PREEMPT is turned off. I tested making it return 1 in that
case, but that yielded tons of warnings.

The simpler fix for tlb_uv.c would be to just drop the WARN_ON.

- uv_flush_send_and_wait() should return a pointer if the broadcast
remote tlb shootdown requests fail. That causes the conventional IPI
method of shootdown to be used.

Diffed against 2.6.29-rc2
(Ingo's tree)

Signed-off-by: Cliff Wickman <cpw@xxxxxxx>
---
arch/x86/kernel/tlb_uv.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux/arch/x86/kernel/tlb_uv.c
===================================================================
--- linux.orig/arch/x86/kernel/tlb_uv.c
+++ linux/arch/x86/kernel/tlb_uv.c
@@ -259,7 +259,7 @@ const struct cpumask *uv_flush_send_and_
* the cpu's, all of which are still in the mask.
*/
__get_cpu_var(ptcstats).ptc_i++;
- return 0;
+ return flush_mask;
}

/*
@@ -316,7 +316,9 @@ const struct cpumask *uv_flush_tlb_other
int locals = 0;
struct bau_desc *bau_desc;

+#ifdef CONFIG_PREEMPT
WARN_ON(!in_atomic());
+#endif

cpumask_andnot(flush_mask, cpumask, cpumask_of(cpu));

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