From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: "Richard W.M. Jones" <rjones@redhat.com>, qemu-devel@nongnu.org
Cc: qemu-riscv@nongnu.org, palmer@dabbelt.com,
alistair.francis@wdc.com, bin.meng@windriver.com,
liweiwei@iscas.ac.cn, dbarboza@ventanamicro.com,
zhiwei_liu@linux.alibaba.com, pbonzini@redhat.com
Subject: Re: [PATCH v3] target/riscv: Use env_archcpu for better performance
Date: Mon, 9 Oct 2023 15:47:50 +0200 [thread overview]
Message-ID: <86ee8b11-aabc-fbfd-088c-ceb6551602f9@linaro.org> (raw)
In-Reply-To: <20231009124859.3373696-2-rjones@redhat.com>
On 9/10/23 14:48, Richard W.M. Jones wrote:
> RISCV_CPU(cs) uses a checked cast. When QOM cast debugging is enabled
> this adds about 5% total overhead when emulating RV64 on x86-64 host.
>
> Using a RISC-V guest with 16 vCPUs, 16 GB of guest RAM, virtio-blk
> disk. The guest has a copy of the qemu source tree. The test
> involves compiling the qemu source tree with 'make clean; time make -j16'.
>
> Before making this change the compile step took 449 & 447 seconds over
> two consecutive runs.
>
> After making this change: 428 & 421 seconds.
>
> The saving is over 5%.
>
> Thanks: Paolo Bonzini
> Thanks: Philippe Mathieu-Daudé
> Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
> ---
> target/riscv/cpu_helper.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
next prev parent reply other threads:[~2023-10-09 13:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-09 12:48 [PATCH v3] target/riscv: Use env_archcpu for better performance Richard W.M. Jones
2023-10-09 12:48 ` Richard W.M. Jones
2023-10-09 13:47 ` Philippe Mathieu-Daudé [this message]
2023-10-10 16:48 ` Richard Henderson
2023-10-11 1:09 ` Alistair Francis
2023-10-11 1:19 ` Alistair Francis
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=86ee8b11-aabc-fbfd-088c-ceb6551602f9@linaro.org \
--to=philmd@linaro.org \
--cc=alistair.francis@wdc.com \
--cc=bin.meng@windriver.com \
--cc=dbarboza@ventanamicro.com \
--cc=liweiwei@iscas.ac.cn \
--cc=palmer@dabbelt.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-riscv@nongnu.org \
--cc=rjones@redhat.com \
--cc=zhiwei_liu@linux.alibaba.com \
/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).