From: Jens Axboe <[email protected]>
To: Stefan Metzmacher <[email protected]>, [email protected]
Subject: Re: [RFC PATCH 00/10] Complete setup before calling wake_up_new_task() and improve task->comm
Date: Wed, 17 Mar 2021 16:42:49 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 3/15/21 11:01 AM, Stefan Metzmacher wrote:
> Hi,
>
> now that we have an explicit wake_up_new_task() in order to start the
> result from create_io_thread(), we should things up before calling
> wake_up_new_task().
>
> There're also some improvements around task->comm:
> - We return 0 bytes for /proc/<pid>/cmdline
> - We no longer allow a userspace process to change
> /proc/<pid>/[task/<tid>]/comm
> - We dynamically generate comm names (up to 63 chars)
> via io_wq_worker_comm(), similar to wq_worker_comm()
>
> While doing this I noticed a few places we check for
> PF_KTHREAD, but not PF_IO_WORKER, maybe we should
> have something like a PS_IS_KERNEL_THREAD_MASK() macro
> that should be used in generic places and only
> explicitly use PF_IO_WORKER or PF_KTHREAD checks where the
> difference matters.
>
> There are also quite a number of cases where we use
> same_thread_group(), I guess these need to be checked.
> Should that return true if userspace threads and their iothreds
> are compared?
>
> I've compiled but didn't test, I hope there's something useful...
Looks pretty good to me. Can I talk you into splitting this into
a series for 5.12, and then a 5.13 on top? It looks a bit mixed
right now. For 5.12, basically just things we absolutely need for
release. Any cleanups or improvements on top should go to 5.13.
--
Jens Axboe
next prev parent reply other threads:[~2021-03-17 22:43 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 23:27 Problems with io_threads Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 00/10] Complete setup before calling wake_up_new_task() and improve task->comm Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 01/10] kernel: always initialize task->pf_io_worker to NULL Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 02/10] io_uring: io_sq_thread() no longer needs to reset current->pf_io_worker Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 03/10] io-wq: call set_task_comm() before wake_up_new_task() Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 04/10] io_uring: complete sq_thread setup before calling wake_up_new_task() Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 05/10] io-wq: protect against future set_task_comm() overflows Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 06/10] io_uring: " Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 07/10] fs/proc: hide PF_IO_WORKER in get_task_cmdline() Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 08/10] fs/proc: protect /proc/<pid>/[task/<tid>]/comm for PF_IO_WORKER Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 09/10] io-wq: add io_wq_worker_comm() helper function for dynamic proc_task_comm() generation Stefan Metzmacher
2021-03-15 17:01 ` [RFC PATCH 10/10] fs/proc: make use of io_wq_worker_comm() for PF_IO_WORKER threads Stefan Metzmacher
2021-03-17 22:42 ` Jens Axboe [this message]
2021-03-17 23:06 ` [RFC PATCH 00/10] Complete setup before calling wake_up_new_task() and improve task->comm Stefan Metzmacher
2021-03-17 23:26 ` Jens Axboe
2021-03-20 0:00 ` [PATCH v2 0/5] " Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 1/5] kernel: always initialize task->pf_io_worker to NULL Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 2/5] io_uring: io_sq_thread() no longer needs to reset current->pf_io_worker Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 3/5] io-wq: call set_task_comm() before wake_up_new_task() Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 4/5] io_uring: complete sq_thread setup before calling wake_up_new_task() Stefan Metzmacher
2021-03-20 0:00 ` [PATCH v2 5/5] fs/proc: hide PF_IO_WORKER in get_task_cmdline() Stefan Metzmacher
2021-03-20 1:24 ` [PATCH v2 0/5] Complete setup before calling wake_up_new_task() and improve task->comm Jens Axboe
2021-03-20 19:22 ` Stefan Metzmacher
2021-03-20 22:39 ` Jens Axboe
2021-03-19 23:46 ` Problems with io_threads Jens Axboe
2021-03-20 0:25 ` Stefan Metzmacher
2021-03-20 1:20 ` Jens Axboe
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