Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH 2/5] /dev/vring: simple userspace-kernel ringbuffer interface. | Date | Sun, 20 Apr 2008 02:45:59 +1000 |
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On Sunday 20 April 2008 02:33:22 Evgeniy Polyakov wrote: > On Sun, Apr 20, 2008 at 02:05:31AM +1000, Rusty Russell (rusty@rustcorp.com.au) wrote: > > There are two reasons not to grab the lock. It turns out that if we > > tried to lock here, we'd deadlock, since the callbacks are called under > > the lock. Secondly, it's possible to implement an atomic > > vring_used_buffer variant, which could fail: this would avoid using the > > thread most of the time. > > Yep, I decided that too. But it limits its usage to tun only or any > other system where only single thread picks up results, so no generic > userspace ring buffers?
I don't think so, it just externalizes the locking. The mutex protects the attaching and detaching of the ops structure, some other lock or code protects simultenous kernel ring accesses.
Cheers, Rusty.
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