arch/x86/platform/uv: fix incorrect tlb flush all issue

The flush tlb optimization code has logical issue on UV platform.  It
doesn't flush the full range at all, since it simply ignores its 'end'
parameter (and hence also the "all" indicator) in uv_flush_tlb_others()
function.

Cliff's notes:

: 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.

Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Tested-by: Cliff Wickman <cpw@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h
index b47c2a82ff1546a7efcd77a820a990d1e08bef00..062921ef34e9136100d3b4820826642dd45f223b 100644 (file)
--- a/arch/x86/include/asm/uv/uv.h
+++ b/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 */

diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index b8b3a37c80cd75e96559e67876206ad603b53741..dbbdca5f508c45bdfb34395aeeb42e500e9f1f1f 100644 (file)
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -1034,7 +1034,8 @@ static int set_distrib_bits(struct cpumask *flush_mask, struct bau_control *bcp,
  * 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 cpumask *flush_mask, struct bau_control *bcp,
  */
 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_others(const struct cpumask *cpumask,
 
        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,