From: Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
To: Matt Helsley <matthltc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
Nathan Lynch <nathanl-V7BBcbaFuwjMbYB6QlFGEg@public.gmane.org>
Subject: Re: [PATCH 3/4] restart thread safety: remove malloc from genstack
Date: Fri, 30 Jul 2010 14:57:36 -0400 [thread overview]
Message-ID: <4C5320A0.6000205@cs.columbia.edu> (raw)
In-Reply-To: <20100730184641.GB3426-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org>
Matt Helsley wrote:
> On Fri, Jul 30, 2010 at 01:08:32PM -0400, Oren Laadan wrote:
>> We use clone and eclone directly and not through glibc, therefore
>> must explicitly care about thread-safety of malloc.
>>
>> This patch eliminates the use of malloc() in genstack_alloc().
>> Use mmap() instead. While an overkill, I don't expect performance
>> issues of this.
>
> Should work so long as we know the glibc mmap wrappers themselves are
> reentrant/thread-safe. I expect they are but this might be a good thing
> to confirm.
True. And that goes for every system call we use in there -
including, for example, setsid().
One alternative is to call all those syscall directly using
the syscall() syscall. Not sure it's worth our time now, though.
Oren.
next prev parent reply other threads:[~2010-07-30 18:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-26 18:37 user-cr thread safety Nathan Lynch
2010-07-29 14:56 ` Oren Laadan
[not found] ` <4C51968D.3000301-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-07-29 17:37 ` Nathan Lynch
2010-07-29 22:14 ` Oren Laadan
2010-07-30 17:08 ` [PATCH 1/4] restart: check for overflow when counting (nested) vpids Oren Laadan
2010-07-30 17:08 ` [PATCH 2/4] restart thread safety: remove malloc from ckpt_fork_child Oren Laadan
2010-07-30 17:08 ` [PATCH 3/4] restart thread safety: remove malloc from genstack Oren Laadan
[not found] ` <1280509713-6745-3-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-07-30 18:46 ` Matt Helsley
[not found] ` <20100730184641.GB3426-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org>
2010-07-30 18:57 ` Oren Laadan [this message]
2010-08-04 23:08 ` Nathan Lynch
2010-07-30 17:08 ` [PATCH 4/4] restart thread-safety: avoid malloc in ckpt_msg() Oren Laadan
[not found] ` <1280509713-6745-4-git-send-email-orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
2010-08-04 23:30 ` Nathan Lynch
2010-08-04 23:56 ` Oren Laadan
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