Re: [PATCH v3] perf bench: add --write-size option to sched pipe

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Jun 01, 2026 at 04:10:29AM -0700, Breno Leitao wrote:
> Hello Namhyung,
> 
> On Wed, May 27, 2026 at 10:31:10AM -0700, Namhyung Kim wrote:
> > On Wed, May 27, 2026 at 06:42:59AM -0700, Breno Leitao wrote:
> > > +static inline int write_pipe(struct thread_data *td)
> > > +{
> > > +	unsigned int done = 0;
> > > +	int ret;
> > > +
> > > +	while (done < write_size) {
> > > +		ret = write(td->pipe_write, td->buf + done, write_size - done);
> > > +		if (ret < 0) {
> > > +			if (nonblocking && errno == EWOULDBLOCK)
> > > +				continue;
> > 
> > Don't we also need the blocking part?
> 
> Just to make sure I'm reading this right: do you mean the writer
> should epoll_wait() on EPOLLOUT before retrying (symmetric to what
> read_pipe() does for EPOLLIN), so we sleep until the pipe drains
> instead of spinning on EWOULDBLOCK? Or are you pointing at something
> else — e.g. behavior in the blocking (!nonblocking) path?

I simply meant if it needs to check EINTR if !nonblocking.

Thanks,
Namhyung