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From: Richard Weinberger <richard@nod.at>
To: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: linux-um@lists.infradead.org
Subject: Re: [PATCH] um: Try to avoid kmalloc in signal handling
Date: Thu, 03 Jan 2019 22:42:45 +0100	[thread overview]
Message-ID: <8232816.4fJl4d8jsT@blindfold> (raw)
In-Reply-To: <da88ec54-3d0b-360a-863d-59e29c8eaa00@cambridgegreys.com>

Am Donnerstag, 3. Januar 2019, 22:29:17 CET schrieb Anton Ivanov:
> Second thought - this should not use kmalloc at all if it can. It should 
> either go on the stack the way it used to do before 
> b6024b21fec8367ef961a771cc9dde31f1831965 or it should have a sufficient 
> "register stack" to push registers for all use cases.
> 
> Kmalloc/ATOMIC can fail just because it feels like it which means that 
> this can throw a panic() under very heavy IO.

Not good. :-(
We cannot go back to stack based allocation. The stack is too small for
AVX register sets.
Maybe we can preallocate it.
(And check what arch/x86/ does)

Thanks,
//richard



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  reply	other threads:[~2019-01-03 21:42 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-03 16:09 [PATCH] um: Try to avoid kmalloc in signal handling anton.ivanov
2019-01-03 17:13 ` Anton Ivanov
2019-01-03 21:29   ` Anton Ivanov
2019-01-03 21:42     ` Richard Weinberger [this message]
2019-01-04  7:07       ` Anton Ivanov
2019-01-04  7:48       ` Anton Ivanov
2019-01-04 15:50       ` Anton Ivanov
2019-01-07 10:07         ` Anton Ivanov
  -- strict thread matches above, loose matches on Subject: below --
2019-01-04 10:05 anton.ivanov
2019-01-04 10:13 ` Richard Weinberger
2019-01-04 10:19   ` Anton Ivanov
2019-01-04 10:33     ` Richard Weinberger
2019-01-04 10:49       ` Anton Ivanov
2019-01-04 11:31       ` Anton Ivanov

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