From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Anthony Liguori <aliguori@us.ibm.com>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [Qemu-devel] [patch 1/2] qemu: sem/thread helpers
Date: Wed, 11 Mar 2009 16:48:01 +0000 [thread overview]
Message-ID: <200903111648.02530.paul@codesourcery.com> (raw)
In-Reply-To: <20090311161942.482576079@localhost.localdomain>
> +int qemu_sem_init(QemuSem *sem);
> +int qemu_sem_lock(QemuSem *sem);
Please don't introduce yet annother set of locking routines.
Also, your function names suggest you actually want a mutex, not a semaphore.
> +int qemu_sem_lock(QemuSem *sem)
> +{
This is bogus. You never check the return value.
> +QemuSem qemu_sem;
It's entirely unclear what is actually protected by the semaphore.
What exactly does the IO thread do? AFAICS device MMIO is still run from
within the CPU thread. Device code is not threadsafe (and probably never will
be), so you can't run any of the device callbacks in the IO thread either.
Doesn't seem like there's a lot left for it to do...
Paul
next prev parent reply other threads:[~2009-03-11 16:48 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-11 16:16 [Qemu-devel] [patch 0/2] RFC: separate thread for IO Marcelo Tosatti
2009-03-11 16:16 ` [Qemu-devel] [patch 1/2] qemu: sem/thread helpers Marcelo Tosatti
2009-03-11 16:33 ` [Qemu-devel] " Anthony Liguori
2009-03-11 16:48 ` Paul Brook [this message]
2009-03-11 16:56 ` [Qemu-devel] " Anthony Liguori
2009-03-11 16:58 ` Marcelo Tosatti
2009-03-18 18:47 ` Marcelo Tosatti
2009-03-15 14:15 ` Avi Kivity
2009-03-17 17:42 ` Marcelo Tosatti
2009-03-17 23:07 ` Paul Brook
2009-03-17 23:43 ` Marcelo Tosatti
2009-03-11 16:16 ` [Qemu-devel] [patch 2/2] qemu: separate thread for io Marcelo Tosatti
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