From: Alan Stern <stern@rowland.harvard.edu>
To: Jim Baxter <jim_baxter@mentor.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-usb@vger.kernel.org,
"Resch Carsten \(CM/ESO6\)" <Carsten.Resch@de.bosch.com>,
"Rosca, Eugeniu \(ADITG/ESB\)" <erosca@de.adit-jv.com>
Subject: Re: PROBLEM: Long Workqueue delays.
Date: Tue, 18 Aug 2020 10:48:18 -0400 [thread overview]
Message-ID: <20200818144818.GB144306@rowland.harvard.edu> (raw)
In-Reply-To: <1838f2c3-7915-9e5b-3112-6b082b945410@mentor.com>
On Tue, Aug 18, 2020 at 11:54:51AM +0100, Jim Baxter wrote:
> On 17/08/2020 19:47, Alan Stern wrote:
> >
> > Unplugging a R/W USB drive without unmounting it first is a great way to
> > corrupt the data.
> >
> Thank you, post development we will only mount the USB stick as R/O.
>
> >> Using perf Iidentified the hub_events workqueue was spending a lot of time in
> >> invalidate_partition(), I have included a cut down the captured data from perf in
> >> [2] which shows the additional functions where the kworker spends most of its time.
> >
> > invalidate_partition() is part of the block layer, not part of USB. It
> > gets called whenever a drive is removed from the system, no matter what
> > type of drive it is. You should ask the people involved in that
> > subsystem why it takes so long.
> >
>
> I included the linux-mm list but missed the filesystem, I will ask the question
> to the linux-fsdevel too.
What about linux-block? The block layer is different from the
memory-management (mm) layer.
Alan Stern
next prev parent reply other threads:[~2020-08-18 14:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-17 11:40 Jim Baxter
2020-08-17 11:57 ` Greg KH
2020-08-17 18:24 ` Jim Baxter
2020-08-17 18:47 ` Alan Stern
2020-08-18 10:54 ` Jim Baxter
2020-08-18 14:48 ` Alan Stern [this message]
2020-08-17 15:25 ` Alan Stern
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