From: Johannes Berg <johannes@sipsolutions.net>
To: Anton Ivanov <anton.ivanov@cambridgegreys.com>,
linux-um@lists.infradead.org
Cc: richard@nod.at
Subject: Re: [PATCH v5] um: Enable preemption in UML
Date: Fri, 22 Sep 2023 10:13:28 +0200 [thread overview]
Message-ID: <423e8ee5126e1dffda5f8877d07611a21972eea7.camel@sipsolutions.net> (raw)
In-Reply-To: <28f0be57-829b-9ddf-7b0d-a6c84932cbda@cambridgegreys.com>
On Fri, 2023-09-22 at 09:01 +0100, Anton Ivanov wrote:
>
> My favorite test which I run on all changes is:
>
> find /usr -type f -exec cat {} > /dev/null \;
>
> On Debian this forks /bin/cat for each file and does IO on it. That test passes here every time :(
Oh, apart from the splat, it all _works_ fine.
> However, I did not have debug turned on. So, I would not be surprised if something in the debug
OK.
> portion of the config makes the crashes more likely.
It's just a debug warning for me, no real crash.
> Otherwise, each fork is a forced tlb_flush_all, so it is a massive tlb exercise. Any bugs, locking, etc are likely to show up.
>
Yes, but when does the fork actually happen?
That part confuses me - the fork_handler() seems to be called at various
kind of random points in time after?
johannes
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next prev parent reply other threads:[~2023-09-22 8:13 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-22 6:52 [PATCH v5] um: Enable preemption in UML anton.ivanov
2023-09-22 7:27 ` Richard Weinberger
2023-09-22 7:29 ` Anton Ivanov
2023-09-22 7:30 ` Johannes Berg
2023-09-22 7:38 ` Anton Ivanov
2023-09-22 7:40 ` Johannes Berg
2023-09-22 8:01 ` Anton Ivanov
2023-09-22 8:13 ` Johannes Berg [this message]
2023-09-22 8:40 ` Anton Ivanov
2023-09-22 8:41 ` Johannes Berg
2023-09-22 8:43 ` Johannes Berg
2023-09-22 9:04 ` Johannes Berg
2023-09-22 9:12 ` Anton Ivanov
2023-09-22 9:06 ` Anton Ivanov
2023-09-22 9:10 ` Johannes Berg
2023-09-22 9:14 ` Johannes Berg
2023-09-22 9:19 ` Anton Ivanov
2023-09-22 9:51 ` Johannes Berg
2023-09-22 9:55 ` Johannes Berg
2023-09-22 10:55 ` Anton Ivanov
2023-09-22 11:17 ` Johannes Berg
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