diff options
| author | Nadav Amit <namit@vmware.com> | 2021-02-20 15:17:07 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-03-06 12:59:10 +0100 |
| commit | 4ce94eabac16b1d2c95762b40f49e5654ab288d7 (patch) | |
| tree | 16fd5d3124ad8ae61e9c22fecc24f9c91adec4e9 /arch/x86/hyperv/mmu.c | |
| parent | 6035152d8eebe16a5bb60398d3e05dc7799067b0 (diff) | |
x86/mm/tlb: Flush remote and local TLBs concurrently
To improve TLB shootdown performance, flush the remote and local TLBs
concurrently. Introduce flush_tlb_multi() that does so. Introduce
paravirtual versions of flush_tlb_multi() for KVM, Xen and hyper-v (Xen
and hyper-v are only compile-tested).
While the updated smp infrastructure is capable of running a function on
a single local core, it is not optimized for this case. The multiple
function calls and the indirect branch introduce some overhead, and
might make local TLB flushes slower than they were before the recent
changes.
Before calling the SMP infrastructure, check if only a local TLB flush
is needed to restore the lost performance in this common case. This
requires to check mm_cpumask() one more time, but unless this mask is
updated very frequently, this should impact performance negatively.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com> # Hyper-v parts
Reviewed-by: Juergen Gross <jgross@suse.com> # Xen and paravirt parts
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20210220231712.2475218-5-namit@vmware.com
Diffstat (limited to 'arch/x86/hyperv/mmu.c')
| -rw-r--r-- | arch/x86/hyperv/mmu.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c index 2c87350c1fb0..681dba8de4f2 100644 --- a/arch/x86/hyperv/mmu.c +++ b/arch/x86/hyperv/mmu.c @@ -52,8 +52,8 @@ static inline int fill_gva_list(u64 gva_list[], int offset, return gva_n - offset; } -static void hyperv_flush_tlb_others(const struct cpumask *cpus, - const struct flush_tlb_info *info) +static void hyperv_flush_tlb_multi(const struct cpumask *cpus, + const struct flush_tlb_info *info) { int cpu, vcpu, gva_n, max_gvas; struct hv_tlb_flush **flush_pcpu; @@ -61,7 +61,7 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus, u64 status = U64_MAX; unsigned long flags; - trace_hyperv_mmu_flush_tlb_others(cpus, info); + trace_hyperv_mmu_flush_tlb_multi(cpus, info); if (!hv_hypercall_pg) goto do_native; @@ -164,7 +164,7 @@ check_status: if (!(status & HV_HYPERCALL_RESULT_MASK)) return; do_native: - native_flush_tlb_others(cpus, info); + native_flush_tlb_multi(cpus, info); } static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus, @@ -239,6 +239,6 @@ void hyperv_setup_mmu_ops(void) return; pr_info("Using hypercall for remote TLB flush\n"); - pv_ops.mmu.flush_tlb_others = hyperv_flush_tlb_others; + pv_ops.mmu.flush_tlb_multi = hyperv_flush_tlb_multi; pv_ops.mmu.tlb_remove_table = tlb_remove_table; } |