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x86: change flush_tlb_others to take a const struct cpumask

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Impact: reduce stack usage, use new cpumask API.

This is made a little more tricky by uv_flush_tlb_others which
actually alters its argument, for an IPI to be sent to the remaining
cpus in the mask.

I solve this by allocating a cpumask_var_t for this case and falling back
to IPI should this fail.

To eliminate temporaries in the caller, all flush_tlb_others implementations
now do the this-cpu-elimination step themselves.

Note also the curious "cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask)"
which has been there since pre-git and yet f->flush_cpumask is always zero
at this point.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
This commit is contained in:
Rusty Russell
2009-01-10 21:58:09 -08:00
committed by Ingo Molnar
parent 802bf931f2
commit 4595f9620c
7 changed files with 93 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
arch/x86/xen/enlighten.c
View File

@@ -634,35 +634,27 @@ static void xen_flush_tlb_single(unsigned long addr)
preempt_enable();
}
static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
unsigned long va)
static void xen_flush_tlb_others(const struct cpumask *cpus,
struct mm_struct *mm, unsigned long va)
{
struct {
struct mmuext_op op;
cpumask_t mask;
DECLARE_BITMAP(mask, NR_CPUS);
} *args;
cpumask_t cpumask = *cpus;
struct multicall_space mcs;
/*
* A couple of (to be removed) sanity checks:
*
* - current CPU must not be in mask
* - mask must exist :)
*/
BUG_ON(cpus_empty(cpumask));
BUG_ON(cpu_isset(smp_processor_id(), cpumask));
BUG_ON(cpumask_empty(cpus));
BUG_ON(!mm);
/* If a CPU which we ran on has gone down, OK. */
cpus_and(cpumask, cpumask, cpu_online_map);
if (cpus_empty(cpumask))
return;
mcs = xen_mc_entry(sizeof(*args));
args = mcs.args;
args->mask = cpumask;
args->op.arg2.vcpumask = &args->mask;
args->op.arg2.vcpumask = to_cpumask(args->mask);
/* Remove us, and any offline CPUS. */
cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
if (unlikely(cpumask_empty(to_cpumask(args->mask))))
goto issue;
if (va == TLB_FLUSH_ALL) {
args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
@@ -673,6 +665,7 @@ static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
issue:
xen_mc_issue(PARAVIRT_LAZY_MMU);
}