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-rw-r--r--arch/sparc/kernel/smp_64.c65
1 files changed, 14 insertions, 51 deletions
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index e286e2badc8a..e38d8bf454e8 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1039,38 +1039,9 @@ void smp_fetch_global_pmu(void)
* are flush_tlb_*() routines, and these run after flush_cache_*()
* which performs the flushw.
*
- * The SMP TLB coherency scheme we use works as follows:
- *
- * 1) mm->cpu_vm_mask is a bit mask of which cpus an address
- * space has (potentially) executed on, this is the heuristic
- * we use to avoid doing cross calls.
- *
- * Also, for flushing from kswapd and also for clones, we
- * use cpu_vm_mask as the list of cpus to make run the TLB.
- *
- * 2) TLB context numbers are shared globally across all processors
- * in the system, this allows us to play several games to avoid
- * cross calls.
- *
- * One invariant is that when a cpu switches to a process, and
- * that processes tsk->active_mm->cpu_vm_mask does not have the
- * current cpu's bit set, that tlb context is flushed locally.
- *
- * If the address space is non-shared (ie. mm->count == 1) we avoid
- * cross calls when we want to flush the currently running process's
- * tlb state. This is done by clearing all cpu bits except the current
- * processor's in current->mm->cpu_vm_mask and performing the
- * flush locally only. This will force any subsequent cpus which run
- * this task to flush the context from the local tlb if the process
- * migrates to another cpu (again).
- *
- * 3) For shared address spaces (threads) and swapping we bite the
- * bullet for most cases and perform the cross call (but only to
- * the cpus listed in cpu_vm_mask).
- *
- * The performance gain from "optimizing" away the cross call for threads is
- * questionable (in theory the big win for threads is the massive sharing of
- * address space state across processors).
+ * mm->cpu_vm_mask is a bit mask of which cpus an address
+ * space has (potentially) executed on, this is the heuristic
+ * we use to limit cross calls.
*/
/* This currently is only used by the hugetlb arch pre-fault
@@ -1080,18 +1051,13 @@ void smp_fetch_global_pmu(void)
void smp_flush_tlb_mm(struct mm_struct *mm)
{
u32 ctx = CTX_HWBITS(mm->context);
- int cpu = get_cpu();
- if (atomic_read(&mm->mm_users) == 1) {
- cpumask_copy(mm_cpumask(mm), cpumask_of(cpu));
- goto local_flush_and_out;
- }
+ get_cpu();
smp_cross_call_masked(&xcall_flush_tlb_mm,
ctx, 0, 0,
mm_cpumask(mm));
-local_flush_and_out:
__flush_tlb_mm(ctx, SECONDARY_CONTEXT);
put_cpu();
@@ -1114,17 +1080,15 @@ void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long
{
u32 ctx = CTX_HWBITS(mm->context);
struct tlb_pending_info info;
- int cpu = get_cpu();
+
+ get_cpu();
info.ctx = ctx;
info.nr = nr;
info.vaddrs = vaddrs;
- if (mm == current->mm && atomic_read(&mm->mm_users) == 1)
- cpumask_copy(mm_cpumask(mm), cpumask_of(cpu));
- else
- smp_call_function_many(mm_cpumask(mm), tlb_pending_func,
- &info, 1);
+ smp_call_function_many(mm_cpumask(mm), tlb_pending_func,
+ &info, 1);
__flush_tlb_pending(ctx, nr, vaddrs);
@@ -1134,14 +1098,13 @@ void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long
void smp_flush_tlb_page(struct mm_struct *mm, unsigned long vaddr)
{
unsigned long context = CTX_HWBITS(mm->context);
- int cpu = get_cpu();
- if (mm == current->mm && atomic_read(&mm->mm_users) == 1)
- cpumask_copy(mm_cpumask(mm), cpumask_of(cpu));
- else
- smp_cross_call_masked(&xcall_flush_tlb_page,
- context, vaddr, 0,
- mm_cpumask(mm));
+ get_cpu();
+
+ smp_cross_call_masked(&xcall_flush_tlb_page,
+ context, vaddr, 0,
+ mm_cpumask(mm));
+
__flush_tlb_page(context, vaddr);
put_cpu();