From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Riccardo Mancini <rickyman7@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>,
Ian Rogers <irogers@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Mark Rutland <mark.rutland@arm.com>, Jiri Olsa <jolsa@redhat.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-perf-users <linux-perf-users@vger.kernel.org>,
Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Subject: Re: [RFC PATCH 03/10] perf workqueue: add threadpool start and stop functions
Date: Fri, 16 Jul 2021 13:29:15 -0300 [thread overview]
Message-ID: <YPGz2xTCa/EkvrxY@kernel.org> (raw)
In-Reply-To: <5866e3456645659423030339f71f3461659ffe2d.camel@gmail.com>
Em Fri, Jul 16, 2021 at 03:53:58PM +0200, Riccardo Mancini escreveu:
> On Thu, 2021-07-15 at 16:48 -0700, Namhyung Kim wrote:
> > On Tue, Jul 13, 2021 at 5:11 AM Riccardo Mancini <rickyman7@gmail.com> wrote:
> > > +++ b/tools/perf/util/workqueue/threadpool.c
> > [SNIP]
> > > +/**
> > > + * wait_thread - receive ack from thread
> > > + *
> > > + * NB: call only from main thread!
> > > + */
> > > +static int wait_thread(struct thread_struct *thread)
> > > +{
> > > + int res;
> > > + enum thread_msg msg = THREAD_MSG__UNDEFINED;
> > > +
> > > + res = read(thread->pipes.from[0], &msg, sizeof(msg));
> > > + if (res < 0) {
> > Maybe it needs to handle -EINTR.
> Its behaviour should be retry, right?
> Since these reads are used multiple times in the code, maybe I'm better off
> writing a wrapper function handling also EINTR.
Take a look at readn():
tools/lib/perf/lib.c
static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
{
void *buf_start = buf;
size_t left = n;
while (left) {
/* buf must be treated as const if !is_read. */
ssize_t ret = is_read ? read(fd, buf, left) :
write(fd, buf, left);
if (ret < 0 && errno == EINTR)
continue;
if (ret <= 0)
return ret;
left -= ret;
buf += ret;
}
BUG_ON((size_t)(buf - buf_start) != n);
return n;
}
/*
* Read exactly 'n' bytes or return an error.
*/
ssize_t readn(int fd, void *buf, size_t n)
{
return ion(true, fd, buf, n);
}
- Arnaldo
next prev parent reply other threads:[~2021-07-16 16:29 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 12:11 [RFC PATCH 00/10] perf: add workqueue library and use it in synthetic-events Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 01/10] perf workqueue: threadpool creation and destruction Riccardo Mancini
2021-07-14 14:16 ` Arnaldo Carvalho de Melo
2021-07-15 16:31 ` Riccardo Mancini
2021-07-15 20:48 ` Arnaldo Carvalho de Melo
2021-07-15 23:29 ` Namhyung Kim
2021-07-16 13:36 ` Riccardo Mancini
2021-07-19 19:39 ` Namhyung Kim
2021-07-13 12:11 ` [RFC PATCH 02/10] perf tests: add test for workqueue Riccardo Mancini
2021-07-14 15:10 ` Arnaldo Carvalho de Melo
2021-07-15 16:33 ` Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 03/10] perf workqueue: add threadpool start and stop functions Riccardo Mancini
2021-07-14 15:15 ` Arnaldo Carvalho de Melo
2021-07-15 16:42 ` Riccardo Mancini
2021-07-15 20:43 ` Arnaldo Carvalho de Melo
2021-07-15 23:48 ` Namhyung Kim
2021-07-16 13:53 ` Riccardo Mancini
2021-07-16 16:29 ` Arnaldo Carvalho de Melo [this message]
2021-07-13 12:11 ` [RFC PATCH 04/10] perf workqueue: add threadpool execute and wait functions Riccardo Mancini
2021-07-15 23:56 ` Namhyung Kim
2021-07-16 13:55 ` Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 05/10] perf workqueue: add sparse annotation header Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 06/10] perf workqueue: introduce workqueue struct Riccardo Mancini
2021-07-14 15:22 ` Arnaldo Carvalho de Melo
2021-07-15 16:49 ` Riccardo Mancini
2021-07-15 20:47 ` Arnaldo Carvalho de Melo
2021-07-13 12:11 ` [RFC PATCH 07/10] perf workqueue: implement worker thread and management Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 08/10] perf workqueue: add queue_work and flush_workqueue functions Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 09/10] perf workqueue: add utility to execute a for loop in parallel Riccardo Mancini
2021-07-13 12:11 ` [RFC PATCH 10/10] perf synthetic-events: use workqueue parallel_for Riccardo Mancini
2021-07-13 19:14 ` [RFC PATCH 00/10] perf: add workqueue library and use it in synthetic-events Arnaldo Carvalho de Melo
2021-07-19 21:13 ` Jiri Olsa
2021-07-22 16:15 ` Riccardo Mancini
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