From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: ksummit-discuss@lists.linuxfoundation.org
Subject: [Ksummit-discuss] [TECH TOPIC] Beyond per-CPU atomics and rseq syscall: thoroughly abusing mm with the do_on_cpu syscall
Date: Mon, 8 Jul 2019 17:06:47 -0400 (EDT) [thread overview]
Message-ID: <1763198136.14021.1562620007328.JavaMail.zimbra@efficios.com> (raw)
The Restartable Sequences system call [1,2,3,4] introduced in Linux 4.18
has limitations which can be solved by introducing a bytecode
interpreter running in inter-processor interrupt context which accesses
user-space data.
However, there are a handful of reasons why accessing user-space
data from an IPI handler concurrently with user-space execution
is a bad idea, starting with page fault handling. This discussion
aims at gathering feedback from the mm community on the do_on_cpu
system call aiming to solve this gracefully.
[1] "PerCpu Atomics" http://www.linuxplumbersconf.org/2013/ocw/system/presentations/1695/original/LPC%20-%20PerCpu%20Atomics.pdf
[2] "Restartable sequences" https://lwn.net/Articles/650333/
[3] "Restartable sequences restarted" https://lwn.net/Articles/697979/
[4] "Restartable sequences and ops vectors" https://lwn.net/Articles/737662/
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
reply other threads:[~2019-07-08 21:06 UTC|newest]
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