From: Alistair Francis <alistair23@gmail.com>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: Alistair Francis <alistair.francis@wdc.com>,
"qemu-devel@nongnu.org Developers" <qemu-devel@nongnu.org>
Subject: Re: [PATCH 9/9] cputlb: Hoist timestamp outside of loops over tlbs
Date: Tue, 21 Jan 2020 09:02:31 +1000 [thread overview]
Message-ID: <CAKmqyKMkVkrqjXgTjuq4KzNjPz0U2TEJ4j=23KZZauq8Kuzk0Q@mail.gmail.com> (raw)
In-Reply-To: <20200109024907.2730-10-richard.henderson@linaro.org>
On Thu, Jan 9, 2020 at 12:55 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> 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.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
> ---
> accel/tcg/cputlb.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index 761e9d44d7..9f6cb36921 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -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
> * 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 rate;
> size_t new_size = old_size;
> - int64_t now = get_clock_realtime();
> int64_t window_len_ms = 100;
> int64_t window_len_ns = window_len_ms * 1000 * 1000;
> 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));
> }
>
> -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];
> 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);
> }
>
> @@ -310,6 +311,7 @@ static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
> CPUArchState *env = cpu->env_ptr;
> uint16_t asked = data.host_int;
> uint16_t all_dirty, work, to_clean;
> + int64_t now = get_clock_realtime();
>
> 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) {
> 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);
> @@ -446,7 +448,7 @@ static void tlb_flush_page_locked(CPUArchState *env, int midx,
> tlb_debug("forcing full flush midx %d ("
> TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
> midx, lp_addr, lp_mask);
> - tlb_flush_one_mmuidx_locked(env, midx);
> + tlb_flush_one_mmuidx_locked(env, midx, get_clock_realtime());
> } else {
> if (tlb_flush_entry_locked(tlb_entry(env, midx, page), page)) {
> tlb_n_used_entries_dec(env, midx);
> --
> 2.20.1
>
>
next prev parent reply other threads:[~2020-01-20 23:05 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-09 2:48 [PATCH 0/9] cputlb: Various cleanups Richard Henderson
2020-01-09 2:48 ` [PATCH 1/9] cputlb: Merge tlb_table_flush_by_mmuidx into tlb_flush_one_mmuidx_locked Richard Henderson
2020-01-20 0:34 ` Alistair Francis
2020-01-20 13:34 ` Alex Bennée
2020-01-09 2:49 ` [PATCH 2/9] cputlb: Make tlb_n_entries private to cputlb.c Richard Henderson
2020-01-20 0:36 ` Alistair Francis
2020-01-20 8:53 ` Philippe Mathieu-Daudé
2020-01-20 13:34 ` Alex Bennée
2020-01-09 2:49 ` [PATCH 3/9] cputlb: Pass CPUTLBDescFast to tlb_n_entries and sizeof_tlb Richard Henderson
2020-01-20 0:37 ` Alistair Francis
2020-01-20 8:54 ` Philippe Mathieu-Daudé
2020-01-20 13:36 ` Alex Bennée
2020-01-20 13:39 ` Alex Bennée
2020-01-09 2:49 ` [PATCH 4/9] cputlb: Hoist tlb portions in tlb_mmu_resize_locked Richard Henderson
2020-01-20 8:58 ` Philippe Mathieu-Daudé
2020-01-20 12:05 ` Alistair Francis
2020-01-20 13:40 ` Alex Bennée
2020-01-09 2:49 ` [PATCH 5/9] cputlb: Hoist tlb portions in tlb_flush_one_mmuidx_locked Richard Henderson
2020-01-20 8:58 ` Philippe Mathieu-Daudé
2020-01-20 13:41 ` Alex Bennée
2020-01-20 22:56 ` Alistair Francis
2020-01-09 2:49 ` [PATCH 6/9] cputlb: Split out tlb_mmu_flush_locked Richard Henderson
2020-01-20 8:59 ` Philippe Mathieu-Daudé
2020-01-20 13:41 ` Alex Bennée
2020-01-20 22:58 ` Alistair Francis
2020-01-09 2:49 ` [PATCH 7/9] cputlb: Partially merge tlb_dyn_init into tlb_init Richard Henderson
2020-01-20 9:01 ` Philippe Mathieu-Daudé
2020-01-20 14:33 ` Alex Bennée
2020-01-20 23:00 ` Alistair Francis
2020-01-09 2:49 ` [PATCH 8/9] cputlb: Initialize tlbs as flushed Richard Henderson
2020-01-20 14:33 ` Alex Bennée
2020-01-20 23:01 ` Alistair Francis
2020-01-09 2:49 ` [PATCH 9/9] cputlb: Hoist timestamp outside of loops over tlbs Richard Henderson
2020-01-20 9:02 ` Philippe Mathieu-Daudé
2020-01-20 14:36 ` Alex Bennée
2020-01-20 23:02 ` Alistair Francis [this message]
2020-01-20 23:03 ` [PATCH 0/9] cputlb: Various cleanups Alistair Francis
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