From: Dave Jones <davej@codemonkey.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>,
Rusty Russell <rusty@rustcorp.com.au>,
the arch/x86 maintainers <x86@kernel.org>,
Michal Hocko <mhocko@suse.cz>, Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Sasha Levin <sasha.levin@oracle.com>
Subject: Re: Hang on large copy_from_user with PREEMPT_NONE
Date: Tue, 7 Apr 2015 17:09:50 -0400 [thread overview]
Message-ID: <20150407210950.GA26213@codemonkey.org.uk> (raw)
In-Reply-To: <CA+55aFyxCb9aDfh0L4gyvHMSefOFoD7zftRpWbnvf5j9iZVaMw@mail.gmail.com>
On Tue, Apr 07, 2015 at 11:12:31AM -0700, Linus Torvalds wrote:
> On Apr 7, 2015 10:58 AM, "Dave Jones" <davej@codemonkey.org.uk> wrote:
> > >
> > > +#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
> >
> > This needs to be bigger, just to accomodate things like xfs, which
> > on my system is over 1mb. I think some out-of-tree modules
> > (not that I care deeply) are even bigger.
>
> Umm. It will happily copy megabytes of data. Or gigabytes. It just doors it
> in smaller chunks, and make sure to test the return value and possibly
> reschedule in between.
brain no worky. You are of course, correct.
Dave
prev parent reply other threads:[~2015-04-07 21:10 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-06 3:59 Hang on large copy_from_user with PREEMPT_NONE Sasha Levin
2015-04-06 11:24 ` Borislav Petkov
2015-04-06 14:51 ` Sasha Levin
2015-04-06 16:52 ` Borislav Petkov
2015-04-06 17:26 ` Linus Torvalds
2015-04-06 19:08 ` Sasha Levin
2015-04-06 19:36 ` Borislav Petkov
2015-04-06 23:45 ` Sasha Levin
2015-04-06 20:42 ` Linus Torvalds
2015-04-07 1:49 ` Rusty Russell
2015-04-07 9:31 ` Ingo Molnar
2015-04-07 10:39 ` Borislav Petkov
2015-04-07 11:05 ` Ingo Molnar
2015-04-07 14:30 ` Michal Hocko
2015-04-07 14:37 ` Ingo Molnar
2015-04-07 17:00 ` Sasha Levin
2015-04-07 17:33 ` Linus Torvalds
2015-04-07 17:58 ` Dave Jones
[not found] ` <CA+55aFyxCb9aDfh0L4gyvHMSefOFoD7zftRpWbnvf5j9iZVaMw@mail.gmail.com>
2015-04-07 21:09 ` Dave Jones [this message]
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