On Mon, Jun 9, 2025 at 2:21 PM Tanish Desai <tanishdesa...@gmail.com> wrote:
>
> Moved the logic for timestamped logging (~6 lines) from
> a_nocheck__trace_foo(header) into a new qemu_log_timestamp() function in
> util/log.c. This avoids code duplication across binaries and enables reuse as
> a standalone utility.
> Encapsulation helps reduce build size significantly, particularly when many
> trace points are present. On Ubuntu 22 with
> ./configure --target-list=aarch64-softmmu --enable-kvm
> --enable-trace-backends=log,
> this change reduced the build directory size from ~1435.27 MB to ~1412 MB
> (~23 MB saved).
> Notable reductions include:
> trace/: ~2.6 MB
> libqemuutil.a.p: ~3 MB
> A detailed report of size changes (in bytes) for relevant folders and
> subfolders will follow in a trailing mail.
Nice, the output of size(1) on qemu-system-x86_64 is reduced by 3%
(839 KB) when built with gcc 15.1.1 on x86_64:
text data bss dec hex filename
14712231 13652904 149496 28514631 1b31947 before
13852879 13652904 149496 27655279 1a5fc6f after
That is in the same ballpark as the change in build directory size you measured.
> diff --git a/util/log.c b/util/log.c
> index b87d399e4c..996530fe7e 100644
> --- a/util/log.c
> +++ b/util/log.c
> @@ -143,6 +143,24 @@ void qemu_log_unlock(FILE *logfile)
> }
> }
>
> +
> +void qemu_log_timestamp(const char *fmt, ...)
> +{
> + FILE *f = qemu_log_trylock();
> + if (f) {
> + va_list ap;
> + if(message_with_timestamp){
> + struct timeval _now;
> + gettimeofday(&_now, NULL);
> +
> fprintf(f,"%d@%zu.%06zu:",qemu_get_thread_id(),(size_t)_now.tv_sec,
> (size_t)_now.tv_usec);
> + }
> + va_start(ap, fmt);
> + vfprintf(f, fmt, ap);
> + va_end(ap);
> + }
> + qemu_log_unlock(f);
Although calling qemu_log_unlock(NULL) is safe, existing callers
invoke this function inside the if (f) { ... } body. Please follow
that approach for consistency.
Looks good aside from that.
