Re: [ Re: [PATCH] UV: fix incorrect tlb flushall issue]

From: Cliff Wickman
Date: Thu Sep 13 2012 - 17:19:09 EST

On Thu, Sep 13, 2012 at 05:53:10PM +0200, Ingo Molnar wrote:
> Ack?
> Thanks,
> Ingo

But with the adjustment below. The 'end' argument was not declared long.

I tested the patch on a UV.
It has the effect of either clearing 1 or all TLBs in a cpu.
I added some debugging to test for the cases when clearing all TLBs is
overkill, and in practice it happens very seldom.

Sorry I didn't participate in this patch earlier. Jack Steiner was
copied, I believe. But steiner@xxxxxxx is no longer active. Jack has
retired -- congratulations to him, but a very big loss to us, both
professionally and personally.


Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
Acked-by: Cliff Wickman <cpw@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
arch/x86/include/asm/uv/uv.h | 2 +-
arch/x86/platform/uv/tlb_uv.c | 10 +++++++---
2 files changed, 8 insertions(+), 4 deletions(-)

Index: linux/arch/x86/platform/uv/tlb_uv.c
--- linux.orig/arch/x86/platform/uv/tlb_uv.c
+++ linux/arch/x86/platform/uv/tlb_uv.c
@@ -1034,7 +1034,8 @@ static int set_distrib_bits(struct cpuma
* globally purge translation cache of a virtual address or all TLB's
* @cpumask: mask of all cpu's in which the address is to be removed
* @mm: mm_struct containing virtual address range
- * @va: virtual address to be removed (or TLB_FLUSH_ALL for all TLB's on cpu)
+ * @start: start virtual address to be removed from TLB
+ * @end: end virtual address to be remove from TLB
* @cpu: the current cpu
* This is the entry point for initiating any UV global TLB shootdown.
@@ -1056,7 +1057,7 @@ static int set_distrib_bits(struct cpuma
const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm, unsigned long start,
- unsigned end, unsigned int cpu)
+ unsigned long end, unsigned int cpu)
int locals = 0;
int remotes = 0;
@@ -1113,7 +1114,10 @@ const struct cpumask *uv_flush_tlb_other

record_send_statistics(stat, locals, hubs, remotes, bau_desc);

- bau_desc->payload.address = start;
+ if (!end || (end - start) <= PAGE_SIZE)
+ bau_desc->payload.address = start;
+ else
+ bau_desc->payload.address = TLB_FLUSH_ALL;
bau_desc->payload.sending_cpu = cpu;
* uv_flush_send_and_wait returns 0 if all cpu's were messaged,
Index: linux/arch/x86/include/asm/uv/uv.h
--- linux.orig/arch/x86/include/asm/uv/uv.h
+++ linux/arch/x86/include/asm/uv/uv.h
@@ -16,7 +16,7 @@ extern void uv_system_init(void);
extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start,
- unsigned end,
+ unsigned long end,
unsigned int cpu);

#else /* X86_UV */
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