From: Claudio Fontana <cfontana@suse.de>
To: "Philippe Mathieu-Daudé" <f4bug@amsat.org>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Alex Bennée" <alex.bennee@linaro.org>
Cc: qemu-devel@nongnu.org
Subject: Re: [PATCH v3 2/3] accel/tcg: split tcg_start_vcpu_thread
Date: Mon, 19 Oct 2020 12:15:22 +0200 [thread overview]
Message-ID: <42370695-710d-6c9a-c9c6-c9dddc272cd5@suse.de> (raw)
In-Reply-To: <20201015143217.29337-3-cfontana@suse.de>
Hi all,
is this one ok now in your view?
Thanks,
Claudio
On 10/15/20 4:32 PM, Claudio Fontana wrote:
> after the initial split into 3 tcg variants, we proceed to also
> split tcg_start_vcpu_thread.
>
> We actually split it in 2 this time, since the icount variant
> just uses the round robin function.
>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Claudio Fontana <cfontana@suse.de>
> ---
> accel/tcg/tcg-all.c | 5 ++++
> accel/tcg/tcg-cpus-icount.c | 2 +-
> accel/tcg/tcg-cpus-mttcg.c | 29 +++++++++++++++++--
> accel/tcg/tcg-cpus-mttcg.h | 21 --------------
> accel/tcg/tcg-cpus-rr.c | 39 +++++++++++++++++++++++--
> accel/tcg/tcg-cpus-rr.h | 3 +-
> accel/tcg/tcg-cpus.c | 58 -------------------------------------
> accel/tcg/tcg-cpus.h | 1 -
> 8 files changed, 71 insertions(+), 87 deletions(-)
> delete mode 100644 accel/tcg/tcg-cpus-mttcg.h
>
> diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c
> index e42a028043..1ac0b76515 100644
> --- a/accel/tcg/tcg-all.c
> +++ b/accel/tcg/tcg-all.c
> @@ -105,6 +105,11 @@ static int tcg_init(MachineState *ms)
> tcg_exec_init(s->tb_size * 1024 * 1024);
> mttcg_enabled = s->mttcg_enabled;
>
> + /*
> + * Initialize TCG regions
> + */
> + tcg_region_init();
> +
> if (mttcg_enabled) {
> cpus_register_accel(&tcg_cpus_mttcg);
> } else if (icount_enabled()) {
> diff --git a/accel/tcg/tcg-cpus-icount.c b/accel/tcg/tcg-cpus-icount.c
> index d3af3afb6d..82dbe2cacf 100644
> --- a/accel/tcg/tcg-cpus-icount.c
> +++ b/accel/tcg/tcg-cpus-icount.c
> @@ -138,7 +138,7 @@ static void icount_handle_interrupt(CPUState *cpu, int mask)
> }
>
> const CpusAccel tcg_cpus_icount = {
> - .create_vcpu_thread = tcg_start_vcpu_thread,
> + .create_vcpu_thread = rr_start_vcpu_thread,
> .kick_vcpu_thread = qemu_cpu_kick_rr_cpus,
>
> .handle_interrupt = icount_handle_interrupt,
> diff --git a/accel/tcg/tcg-cpus-mttcg.c b/accel/tcg/tcg-cpus-mttcg.c
> index dac724fc85..f2b892a380 100644
> --- a/accel/tcg/tcg-cpus-mttcg.c
> +++ b/accel/tcg/tcg-cpus-mttcg.c
> @@ -33,7 +33,6 @@
> #include "hw/boards.h"
>
> #include "tcg-cpus.h"
> -#include "tcg-cpus-mttcg.h"
>
> /*
> * In the multi-threaded case each vCPU has its own thread. The TLS
> @@ -41,7 +40,7 @@
> * current CPUState for a given thread.
> */
>
> -void *tcg_cpu_thread_fn(void *arg)
> +static void *tcg_cpu_thread_fn(void *arg)
> {
> CPUState *cpu = arg;
>
> @@ -109,8 +108,32 @@ static void mttcg_kick_vcpu_thread(CPUState *cpu)
> cpu_exit(cpu);
> }
>
> +static void mttcg_start_vcpu_thread(CPUState *cpu)
> +{
> + char thread_name[VCPU_THREAD_NAME_SIZE];
> +
> + g_assert(tcg_enabled());
> +
> + parallel_cpus = (current_machine->smp.max_cpus > 1);
> +
> + cpu->thread = g_malloc0(sizeof(QemuThread));
> + cpu->halt_cond = g_malloc0(sizeof(QemuCond));
> + qemu_cond_init(cpu->halt_cond);
> +
> + /* create a thread per vCPU with TCG (MTTCG) */
> + snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/TCG",
> + cpu->cpu_index);
> +
> + qemu_thread_create(cpu->thread, thread_name, tcg_cpu_thread_fn,
> + cpu, QEMU_THREAD_JOINABLE);
> +
> +#ifdef _WIN32
> + cpu->hThread = qemu_thread_get_handle(cpu->thread);
> +#endif
> +}
> +
> const CpusAccel tcg_cpus_mttcg = {
> - .create_vcpu_thread = tcg_start_vcpu_thread,
> + .create_vcpu_thread = mttcg_start_vcpu_thread,
> .kick_vcpu_thread = mttcg_kick_vcpu_thread,
>
> .handle_interrupt = tcg_handle_interrupt,
> diff --git a/accel/tcg/tcg-cpus-mttcg.h b/accel/tcg/tcg-cpus-mttcg.h
> deleted file mode 100644
> index d1bd771f49..0000000000
> --- a/accel/tcg/tcg-cpus-mttcg.h
> +++ /dev/null
> @@ -1,21 +0,0 @@
> -/*
> - * QEMU TCG Multi Threaded vCPUs implementation
> - *
> - * Copyright 2020 SUSE LLC
> - *
> - * This work is licensed under the terms of the GNU GPL, version 2 or later.
> - * See the COPYING file in the top-level directory.
> - */
> -
> -#ifndef TCG_CPUS_MTTCG_H
> -#define TCG_CPUS_MTTCG_H
> -
> -/*
> - * In the multi-threaded case each vCPU has its own thread. The TLS
> - * variable current_cpu can be used deep in the code to find the
> - * current CPUState for a given thread.
> - */
> -
> -void *tcg_cpu_thread_fn(void *arg);
> -
> -#endif /* TCG_CPUS_MTTCG_H */
> diff --git a/accel/tcg/tcg-cpus-rr.c b/accel/tcg/tcg-cpus-rr.c
> index ad50a3765f..f3b262bec7 100644
> --- a/accel/tcg/tcg-cpus-rr.c
> +++ b/accel/tcg/tcg-cpus-rr.c
> @@ -144,7 +144,7 @@ static void deal_with_unplugged_cpus(void)
> * elsewhere.
> */
>
> -void *tcg_rr_cpu_thread_fn(void *arg)
> +static void *tcg_rr_cpu_thread_fn(void *arg)
> {
> CPUState *cpu = arg;
>
> @@ -262,8 +262,43 @@ void *tcg_rr_cpu_thread_fn(void *arg)
> return NULL;
> }
>
> +void rr_start_vcpu_thread(CPUState *cpu)
> +{
> + char thread_name[VCPU_THREAD_NAME_SIZE];
> + static QemuCond *single_tcg_halt_cond;
> + static QemuThread *single_tcg_cpu_thread;
> +
> + g_assert(tcg_enabled());
> + parallel_cpus = false;
> +
> + if (!single_tcg_cpu_thread) {
> + cpu->thread = g_malloc0(sizeof(QemuThread));
> + cpu->halt_cond = g_malloc0(sizeof(QemuCond));
> + qemu_cond_init(cpu->halt_cond);
> +
> + /* share a single thread for all cpus with TCG */
> + snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "ALL CPUs/TCG");
> + qemu_thread_create(cpu->thread, thread_name,
> + tcg_rr_cpu_thread_fn,
> + cpu, QEMU_THREAD_JOINABLE);
> +
> + single_tcg_halt_cond = cpu->halt_cond;
> + single_tcg_cpu_thread = cpu->thread;
> +#ifdef _WIN32
> + cpu->hThread = qemu_thread_get_handle(cpu->thread);
> +#endif
> + } else {
> + /* we share the thread */
> + cpu->thread = single_tcg_cpu_thread;
> + cpu->halt_cond = single_tcg_halt_cond;
> + cpu->thread_id = first_cpu->thread_id;
> + cpu->can_do_io = 1;
> + cpu->created = true;
> + }
> +}
> +
> const CpusAccel tcg_cpus_rr = {
> - .create_vcpu_thread = tcg_start_vcpu_thread,
> + .create_vcpu_thread = rr_start_vcpu_thread,
> .kick_vcpu_thread = qemu_cpu_kick_rr_cpus,
>
> .handle_interrupt = tcg_handle_interrupt,
> diff --git a/accel/tcg/tcg-cpus-rr.h b/accel/tcg/tcg-cpus-rr.h
> index 1936fd16ab..2e5943eda9 100644
> --- a/accel/tcg/tcg-cpus-rr.h
> +++ b/accel/tcg/tcg-cpus-rr.h
> @@ -15,6 +15,7 @@
> /* Kick all RR vCPUs. */
> void qemu_cpu_kick_rr_cpus(CPUState *unused);
>
> -void *tcg_rr_cpu_thread_fn(void *arg);
> +/* start the round robin vcpu thread */
> +void rr_start_vcpu_thread(CPUState *cpu);
>
> #endif /* TCG_CPUS_RR_H */
> diff --git a/accel/tcg/tcg-cpus.c b/accel/tcg/tcg-cpus.c
> index f2b9bbf99e..86fd09545a 100644
> --- a/accel/tcg/tcg-cpus.c
> +++ b/accel/tcg/tcg-cpus.c
> @@ -35,67 +35,9 @@
> #include "hw/boards.h"
>
> #include "tcg-cpus.h"
> -#include "tcg-cpus-mttcg.h"
> -#include "tcg-cpus-rr.h"
>
> /* common functionality among all TCG variants */
>
> -void tcg_start_vcpu_thread(CPUState *cpu)
> -{
> - char thread_name[VCPU_THREAD_NAME_SIZE];
> - static QemuCond *single_tcg_halt_cond;
> - static QemuThread *single_tcg_cpu_thread;
> - static int tcg_region_inited;
> -
> - assert(tcg_enabled());
> - /*
> - * Initialize TCG regions--once. Now is a good time, because:
> - * (1) TCG's init context, prologue and target globals have been set up.
> - * (2) qemu_tcg_mttcg_enabled() works now (TCG init code runs before the
> - * -accel flag is processed, so the check doesn't work then).
> - */
> - if (!tcg_region_inited) {
> - tcg_region_inited = 1;
> - tcg_region_init();
> - parallel_cpus = qemu_tcg_mttcg_enabled() && current_machine->smp.max_cpus > 1;
> - }
> -
> - if (qemu_tcg_mttcg_enabled() || !single_tcg_cpu_thread) {
> - cpu->thread = g_malloc0(sizeof(QemuThread));
> - cpu->halt_cond = g_malloc0(sizeof(QemuCond));
> - qemu_cond_init(cpu->halt_cond);
> -
> - if (qemu_tcg_mttcg_enabled()) {
> - /* create a thread per vCPU with TCG (MTTCG) */
> - snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/TCG",
> - cpu->cpu_index);
> -
> - qemu_thread_create(cpu->thread, thread_name, tcg_cpu_thread_fn,
> - cpu, QEMU_THREAD_JOINABLE);
> -
> - } else {
> - /* share a single thread for all cpus with TCG */
> - snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "ALL CPUs/TCG");
> - qemu_thread_create(cpu->thread, thread_name,
> - tcg_rr_cpu_thread_fn,
> - cpu, QEMU_THREAD_JOINABLE);
> -
> - single_tcg_halt_cond = cpu->halt_cond;
> - single_tcg_cpu_thread = cpu->thread;
> - }
> -#ifdef _WIN32
> - cpu->hThread = qemu_thread_get_handle(cpu->thread);
> -#endif
> - } else {
> - /* For non-MTTCG cases we share the thread */
> - cpu->thread = single_tcg_cpu_thread;
> - cpu->halt_cond = single_tcg_halt_cond;
> - cpu->thread_id = first_cpu->thread_id;
> - cpu->can_do_io = 1;
> - cpu->created = true;
> - }
> -}
> -
> void qemu_tcg_destroy_vcpu(CPUState *cpu)
> {
> cpu_thread_signal_destroyed(cpu);
> diff --git a/accel/tcg/tcg-cpus.h b/accel/tcg/tcg-cpus.h
> index 279ba72e1f..b7ca954e13 100644
> --- a/accel/tcg/tcg-cpus.h
> +++ b/accel/tcg/tcg-cpus.h
> @@ -18,7 +18,6 @@ extern const CpusAccel tcg_cpus_mttcg;
> extern const CpusAccel tcg_cpus_icount;
> extern const CpusAccel tcg_cpus_rr;
>
> -void tcg_start_vcpu_thread(CPUState *cpu);
> void qemu_tcg_destroy_vcpu(CPUState *cpu);
> int tcg_cpu_exec(CPUState *cpu);
> void tcg_handle_interrupt(CPUState *cpu, int mask);
>
next prev parent reply other threads:[~2020-10-19 10:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-15 14:32 [PATCH v3 0/3] tcg-cpus: split into 3 tcg variants Claudio Fontana
2020-10-15 14:32 ` [PATCH v3 1/3] accel/tcg: split CpusAccel into three TCG variants Claudio Fontana
2020-10-15 14:32 ` [PATCH v3 2/3] accel/tcg: split tcg_start_vcpu_thread Claudio Fontana
2020-10-19 10:15 ` Claudio Fontana [this message]
2020-10-15 14:32 ` [PATCH v3 3/3] accel/tcg: rename tcg-cpus functions to match module name Claudio Fontana
2020-10-19 15:00 ` [PATCH v3 0/3] tcg-cpus: split into 3 tcg variants Richard Henderson
2020-11-09 16:02 ` Claudio Fontana
2020-11-10 3:06 ` Richard Henderson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=42370695-710d-6c9a-c9c6-c9dddc272cd5@suse.de \
--to=cfontana@suse.de \
--cc=alex.bennee@linaro.org \
--cc=f4bug@amsat.org \
--cc=qemu-devel@nongnu.org \
--cc=richard.henderson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).