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cputlb: Hoist timestamp outside of loops over tlbs

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Do not call get_clock_realtime() in tlb_mmu_resize_locked,
but hoist outside of any loop over a set of tlbs.  This is
only two (indirect) callers, tlb_flush_by_mmuidx_async_work
and tlb_flush_page_locked, so not onerous.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2019-12-07 14:36:01 -08:00
parent 3c16304af4
commit 3c3959f2d9
1 changed files with 8 additions and 6 deletions
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14
accel/tcg/cputlb.c
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@ -137,12 +137,12 @@ static void tlb_window_reset(CPUTLBDesc *desc, int64_t ns,
* high), since otherwise we are likely to have a significant amount of * high), since otherwise we are likely to have a significant amount of
* conflict misses. * conflict misses.
*/ */
static void tlb_mmu_resize_locked(CPUTLBDesc *desc, CPUTLBDescFast *fast) static void tlb_mmu_resize_locked(CPUTLBDesc *desc, CPUTLBDescFast *fast,
int64_t now)
{ {
size_t old_size = tlb_n_entries(fast); size_t old_size = tlb_n_entries(fast);
size_t rate; size_t rate;
size_t new_size = old_size; size_t new_size = old_size;
int64_t now = get_clock_realtime();
int64_t window_len_ms = 100; int64_t window_len_ms = 100;
int64_t window_len_ns = window_len_ms * 1000 * 1000; int64_t window_len_ns = window_len_ms * 1000 * 1000;
bool window_expired = now > desc->window_begin_ns + window_len_ns; bool window_expired = now > desc->window_begin_ns + window_len_ns;
@ -222,12 +222,13 @@ static void tlb_mmu_flush_locked(CPUTLBDesc *desc, CPUTLBDescFast *fast)
memset(desc->vtable, -1, sizeof(desc->vtable)); memset(desc->vtable, -1, sizeof(desc->vtable));
} }
static void tlb_flush_one_mmuidx_locked(CPUArchState *env, int mmu_idx) static void tlb_flush_one_mmuidx_locked(CPUArchState *env, int mmu_idx,
int64_t now)
{ {
CPUTLBDesc *desc = &env_tlb(env)->d[mmu_idx]; CPUTLBDesc *desc = &env_tlb(env)->d[mmu_idx];
CPUTLBDescFast *fast = &env_tlb(env)->f[mmu_idx]; CPUTLBDescFast *fast = &env_tlb(env)->f[mmu_idx];
tlb_mmu_resize_locked(desc, fast); tlb_mmu_resize_locked(desc, fast, now);
tlb_mmu_flush_locked(desc, fast); tlb_mmu_flush_locked(desc, fast);
} }
@ -310,6 +311,7 @@ static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
CPUArchState *env = cpu->env_ptr; CPUArchState *env = cpu->env_ptr;
uint16_t asked = data.host_int; uint16_t asked = data.host_int;
uint16_t all_dirty, work, to_clean; uint16_t all_dirty, work, to_clean;
int64_t now = get_clock_realtime();
assert_cpu_is_self(cpu); assert_cpu_is_self(cpu);
@ -324,7 +326,7 @@ static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
for (work = to_clean; work != 0; work &= work - 1) { for (work = to_clean; work != 0; work &= work - 1) {
int mmu_idx = ctz32(work); int mmu_idx = ctz32(work);
tlb_flush_one_mmuidx_locked(env, mmu_idx); tlb_flush_one_mmuidx_locked(env, mmu_idx, now);
} }
qemu_spin_unlock(&env_tlb(env)->c.lock); qemu_spin_unlock(&env_tlb(env)->c.lock);
@ -446,7 +448,7 @@ static void tlb_flush_page_locked(CPUArchState *env, int midx,
tlb_debug("forcing full flush midx %d (" tlb_debug("forcing full flush midx %d ("
TARGET_FMT_lx "/" TARGET_FMT_lx ")\n", TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
midx, lp_addr, lp_mask); midx, lp_addr, lp_mask);
tlb_flush_one_mmuidx_locked(env, midx); tlb_flush_one_mmuidx_locked(env, midx, get_clock_realtime());
} else { } else {
if (tlb_flush_entry_locked(tlb_entry(env, midx, page), page)) { if (tlb_flush_entry_locked(tlb_entry(env, midx, page), page)) {
tlb_n_used_entries_dec(env, midx); tlb_n_used_entries_dec(env, midx);