Messages in this thread | | | Date | Thu, 15 Jul 2021 17:47:01 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC PATCH 06/10] perf workqueue: introduce workqueue struct |
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Em Thu, Jul 15, 2021 at 06:49:57PM +0200, Riccardo Mancini escreveu: > Hi Arnaldo, > thanks again for having a look at this patchset! > > On Wed, 2021-07-14 at 12:22 -0300, Arnaldo Carvalho de Melo wrote: > > Em Tue, Jul 13, 2021 at 02:11:17PM +0200, Riccardo Mancini escreveu: > > > This patch adds the workqueue definition, along with simple creation and > > > destruction functions. > > > Furthermore, a simple subtest is added. > > > > > > A workqueue is attached to a pool, on which it executes its workers. > > > Next patches will introduce workers. > > > > > > Signed-off-by: Riccardo Mancini <rickyman7@gmail.com> > > > > <SNIP> > > > + > > > +/** > > > + * create_workqueue - create a workqueue associated to @pool > > > + * > > > + * Only one workqueue can execute on a pool at a time. > > > + */ > > > +struct workqueue_struct *create_workqueue(struct threadpool_struct *pool) > > > > I wonder if we should use the exact same kernel signature and not pass a > > threadpool, essentially having just one threadpool in tools/perf/ that > > is used by create_workqueue(void)? > > I wondered the same thing, but I thought that we'd need it to be dynamically > created to prevent spawning threads at the beginning that might not even be > used. > I think this could be a follow-up patch.
I see your point.
My practice is to use the perf convention for things that don't come from the kernel, and if we do as I suggested, tooling will probably not even see this threadpool struct, i.e. just the workqueue APIs are exposed and workqueue_create() will notice that a threadpool is not yet created, doing its creation behind tooling's back.
- Arnaldo
> Thanks, > Riccardo > > > > > > +{ > > > + int err; > > > + struct workqueue_struct *wq = malloc(sizeof(struct > > > workqueue_struct)); > > > + > > > + > > > + err = pthread_mutex_init(&wq->lock, NULL); > > > + if (err) > > > + goto out_free_wq; > > > + > > > + err = pthread_cond_init(&wq->idle_cond, NULL); > > > + if (err) > > > + goto out_destroy_mutex; > > > + > > > + wq->pool = NULL; > > > + INIT_LIST_HEAD(&wq->busy_list); > > > + INIT_LIST_HEAD(&wq->idle_list); > > > + > > > + INIT_LIST_HEAD(&wq->pending); > > > + > > > + err = pipe(wq->msg_pipe); > > > + if (err) > > > + goto out_destroy_cond; > > > + > > > + wq->task.fn = worker_thread; > > > + > > > + err = attach_threadpool_to_workqueue(wq, pool); > > > + if (err) > > > + goto out_destroy_cond; > > > + > > > + wq->status = WORKQUEUE_STATUS__READY; > > > + > > > + return wq; > > > + > > > +out_destroy_cond: > > > + pthread_cond_destroy(&wq->idle_cond); > > > +out_destroy_mutex: > > > + pthread_mutex_destroy(&wq->lock); > > > +out_free_wq: > > > + free(wq); > > > + return NULL; > > > +} > > > + > > > +/** > > > + * destroy_workqueue - stop @wq workers and destroy @wq > > > + */ > > > +int destroy_workqueue(struct workqueue_struct *wq) > > > +{ > > > + int err = 0, ret; > > > + > > > + ret = detach_threadpool_from_workqueue(wq); > > > + if (ret) { > > > + pr_err("workqueue: error detaching from threadpool.\n"); > > > + err = -1; > > > + } > > > + > > > + ret = pthread_mutex_destroy(&wq->lock); > > > + if (ret) { > > > + err = -1; > > > + pr_err("workqueue: error pthread_mutex_destroy: %s\n", > > > + strerror(errno)); > > > + } > > > + > > > + ret = pthread_cond_destroy(&wq->idle_cond); > > > + if (ret) { > > > + err = -1; > > > + pr_err("workqueue: error pthread_cond_destroy: %s\n", > > > + strerror(errno)); > > > + } > > > + > > > + ret = close(wq->msg_pipe[0]); > > > + if (ret) { > > > + err = -1; > > > + pr_err("workqueue: error close msg_pipe[0]: %s\n", > > > + strerror(errno)); > > > + } > > > + > > > + ret = close(wq->msg_pipe[1]); > > > + if (ret) { > > > + err = -1; > > > + pr_err("workqueue: error close msg_pipe[1]: %s\n", > > > + strerror(errno)); > > > + } > > > + > > > + free(wq); > > > + > > > + return err; > > > +} > > > + > > > +/** > > > + * workqueue_nr_threads - get size of threadpool underlying @wq > > > + */ > > > +int workqueue_nr_threads(struct workqueue_struct *wq) > > > +{ > > > + return threadpool_size(wq->pool); > > > +} > > > diff --git a/tools/perf/util/workqueue/workqueue.h > > > b/tools/perf/util/workqueue/workqueue.h > > > new file mode 100644 > > > index 0000000000000000..86ec1d69274f41db > > > --- /dev/null > > > +++ b/tools/perf/util/workqueue/workqueue.h > > > @@ -0,0 +1,24 @@ > > > +/* SPDX-License-Identifier: GPL-2.0 */ > > > +#ifndef __WORKQUEUE_WORKQUEUE_H > > > +#define __WORKQUEUE_WORKQUEUE_H > > > + > > > +#include <stdlib.h> > > > +#include <sys/types.h> > > > +#include <linux/list.h> > > > +#include "threadpool.h" > > > + > > > +struct work_struct; > > > +typedef void (*work_func_t)(struct work_struct *work); > > > + > > > +struct work_struct { > > > + struct list_head entry; > > > + work_func_t func; > > > +}; > > > + > > > +struct workqueue_struct; > > > + > > > +extern struct workqueue_struct *create_workqueue(struct threadpool_struct > > > *pool); > > > +extern int destroy_workqueue(struct workqueue_struct *wq); > > > + > > > +extern int workqueue_nr_threads(struct workqueue_struct *wq); > > > +#endif /* __WORKQUEUE_WORKQUEUE_H */ > > > -- > > > 2.31.1 > > > > > > >
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- Arnaldo
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