From: Ulf Hansson <ulf.hansson@linaro.org>
To: Tejun Heo <tj@kernel.org>
Cc: Allen Pais <apais@linux.microsoft.com>,
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Subject: Re: [PATCH 9/9] mmc: Convert from tasklet to BH workqueue
Date: Tue, 2 Apr 2024 12:15:45 +0200 [thread overview]
Message-ID: <CAPDyKFp5KET0HR+8MwO4cf0O6W2kyFqHoKcVf5jbgBuLuQUcFA@mail.gmail.com> (raw)
In-Reply-To: <ZgWZDtNU4tCwqyeu@slm.duckdns.org>
On Thu, 28 Mar 2024 at 17:21, Tejun Heo <tj@kernel.org> wrote:
>
> Hello,
>
> On Thu, Mar 28, 2024 at 01:53:25PM +0100, Ulf Hansson wrote:
> > At this point we have suggested to drivers to switch to use threaded
> > irq handlers (and regular work queues if needed too). That said,
> > what's the benefit of using the BH work queue?
>
> BH workqueues should behave about the same as tasklets which have more
> limited interface and is subtly broken in an expensive-to-fix way (around
> freeing in-flight work item), so the plan is to replace tasklets with BH
> workqueues and remove tasklets from the kernel.
Seems like a good approach!
>
> The [dis]advantages of BH workqueues over threaded IRQs or regular threaded
> workqueues are the same as when you compare them to tasklets. No thread
> switching overhead, so latencies will be a bit tighter. Wheteher that
> actually matters really depends on the use case. Here, the biggest advantage
> is that it's mostly interchangeable with tasklets and can thus be swapped
> easily.
Right, thanks for clarifying!
However, the main question is then - if/when it makes sense to use the
BH workqueue for an mmc host driver. Unless there are some HW
limitations, a threaded irq handler should be sufficient, I think.
That said, moving to threaded irq handlers is a different topic and
doesn't prevent us from moving to BH workqueues as it seems like a
step in the right direction.
Kind regards
Uffe
next prev parent reply other threads:[~2024-04-02 10:16 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-27 16:03 [PATCH 0/9] Convert Tasklets to BH Workqueues Allen Pais
2024-03-27 16:03 ` [PATCH 1/9] hyperv: Convert from tasklet to BH workqueue Allen Pais
2024-04-03 16:43 ` Allen
2024-03-27 16:03 ` [PATCH 2/9] dma: " Allen Pais
2024-03-28 5:55 ` Vinod Koul
2024-03-28 10:08 ` Arnd Bergmann
2024-03-28 18:31 ` Vinod Koul
2024-03-28 19:39 ` Allen
2024-03-28 19:49 ` Arnd Bergmann
2024-03-28 20:01 ` Allen
2024-03-29 16:38 ` Vinod Koul
2024-03-29 16:39 ` Vinod Koul
2024-03-28 17:49 ` Allen
2024-04-02 12:25 ` Linus Walleij
2024-04-02 13:11 ` Vinod Koul
2024-03-27 16:03 ` [PATCH 3/9] IB: " Allen Pais
2024-04-07 18:56 ` Zhu Yanjun
2024-03-27 16:03 ` [PATCH 4/9] USB: " Allen Pais
2024-03-27 16:20 ` Duncan Sands
2024-03-27 16:55 ` Greg KH
2024-03-27 16:58 ` Allen
2024-03-27 17:55 ` Alan Stern
2024-03-28 17:54 ` Allen
2024-03-27 16:03 ` [PATCH 5/9] mailbox: " Allen Pais
2024-03-27 16:03 ` [PATCH 6/9] ipmi: " Allen Pais
2024-03-27 17:58 ` Corey Minyard
2024-03-28 17:52 ` Allen
2024-03-28 19:23 ` Corey Minyard
2024-03-28 19:41 ` Allen
2024-03-28 19:52 ` Corey Minyard
2024-03-28 19:58 ` Allen
2024-03-27 16:03 ` [PATCH 7/9] s390: " Allen Pais
2024-04-02 12:48 ` Alexandra Winter
2024-04-03 13:33 ` Allen
2024-04-08 9:33 ` Heiko Carstens
2024-04-08 10:03 ` Harald Freudenberger
2024-03-27 16:03 ` [PATCH 8/9] drivers/media/*: " Allen Pais
2024-04-24 9:12 ` Hans Verkuil
2024-04-24 16:48 ` Allen Pais
2024-03-27 16:03 ` [PATCH 9/9] mmc: " Allen Pais
2024-03-27 19:35 ` Jernej Škrabec
2024-03-28 10:16 ` Christian Loehle
2024-03-28 17:47 ` Allen
2024-03-28 12:53 ` Ulf Hansson
2024-03-28 13:37 ` Linus Walleij
2024-03-28 16:21 ` Tejun Heo
2024-04-02 10:15 ` Ulf Hansson [this message]
2024-04-05 9:28 ` Michał Mirosław
2024-06-03 12:38 ` Aubin Constans
2024-06-03 17:25 ` Allen Pais
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