From: Gleb Natapov <gleb@redhat.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Arun R Bharadwaj <arun@linux.vnet.ibm.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 1/3] Introduce threadlets
Date: Thu, 14 Oct 2010 11:19:37 +0200 [thread overview]
Message-ID: <20101014091937.GE19207@redhat.com> (raw)
In-Reply-To: <AANLkTinwz5Pk+BdLCoPY7mUtUHGgSeyR=vX4WySBOrPi@mail.gmail.com>
On Thu, Oct 14, 2010 at 10:15:30AM +0100, Stefan Hajnoczi wrote:
> I forgot to add that the semantics of cancellation make it difficult
> to write correct user code. Every cancellation user needs to add
> extra synchronization after the cancel call to handle the case where
> the work is currently executing.
>
> This seems tricky to me and I suspect code using this interface will
> be buggy. How about the following?
> 1. Add a return value indicating that the work is currently executing
> (this still requires the caller to add extra synchronization but is at
> least explicit) versus work is no longer on the list.
> 2. Add a flag to block until the work has been cancelled or completed.
> This is useful to callers who are allowed to block.
>
In Linux kernel you usually have two function cancel() and
cancel_sync(). Second variant waits for work completion.
--
Gleb.
next prev parent reply other threads:[~2010-10-14 9:19 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-13 15:30 [Qemu-devel] v5 [PATCH 0/3] qemu: Threadlets: A generic task offloading framework Arun R Bharadwaj
2010-10-13 15:31 ` [Qemu-devel] [PATCH 1/3] Introduce threadlets Arun R Bharadwaj
2010-10-14 9:02 ` Stefan Hajnoczi
2010-10-14 21:17 ` Venkateswararao Jujjuri (JV)
2010-10-15 9:52 ` Stefan Hajnoczi
2010-10-15 14:56 ` Venkateswararao Jujjuri (JV)
2010-10-15 14:42 ` [Qemu-devel] " Paolo Bonzini
2010-10-14 9:15 ` [Qemu-devel] " Stefan Hajnoczi
2010-10-14 9:19 ` Gleb Natapov [this message]
2010-10-14 16:16 ` Avi Kivity
2010-10-14 21:32 ` Venkateswararao Jujjuri (JV)
2010-10-17 8:57 ` Avi Kivity
2010-10-18 10:47 ` Arun R Bharadwaj
2010-10-18 12:29 ` Avi Kivity
2010-10-15 8:05 ` Stefan Hajnoczi
2010-10-13 15:31 ` [Qemu-devel] [PATCH 2/3] Make paio subsystem use threadlets Arun R Bharadwaj
2010-10-13 15:31 ` [Qemu-devel] [PATCH 3/3] Add helper functions for virtio-9p to " Arun R Bharadwaj
-- strict thread matches above, loose matches on Subject: below --
2010-10-13 16:44 [Qemu-devel] [PATCH 0/3]: Threadlets: A generic task offloading framework Arun R Bharadwaj
2010-10-13 16:47 ` [Qemu-devel] [PATCH 1/3]: Introduce threadlets Arun R Bharadwaj
2010-10-19 17:42 [Qemu-devel] v6: [PATCH 0/3]: Threadlets: A generic task offloading framework Arun R Bharadwaj
2010-10-19 17:42 ` [Qemu-devel] [PATCH 1/3] Introduce threadlets Arun R Bharadwaj
2010-10-19 18:36 ` Balbir Singh
2010-10-19 21:00 ` Venkateswararao Jujjuri (JV)
2010-10-20 2:26 ` Balbir Singh
2010-10-19 21:36 ` Anthony Liguori
2010-10-20 2:22 ` Balbir Singh
2010-10-20 3:46 ` Venkateswararao Jujjuri (JV)
2010-10-20 13:05 ` Balbir Singh
2010-10-20 13:13 ` Anthony Liguori
2010-10-20 3:19 ` Venkateswararao Jujjuri (JV)
2010-10-20 8:16 ` Stefan Hajnoczi
2010-10-21 12:10 [Qemu-devel] [PATCH 0/3]: v7: Threadlets: A generic task offloading framework Arun R Bharadwaj
2010-10-21 12:10 ` [Qemu-devel] [PATCH 1/3] Introduce threadlets Arun R Bharadwaj
2010-10-22 7:02 ` Balbir Singh
2010-10-26 14:14 [Qemu-devel] v8: [PATCH 0/3] Threadlets: A generic task offloading framework Arun R Bharadwaj
2010-10-26 14:14 ` [Qemu-devel] [PATCH 1/3] Introduce threadlets Arun R Bharadwaj
2010-10-26 19:31 ` Blue Swirl
2010-11-01 13:40 ` Anthony Liguori
2010-11-05 6:48 ` Arun R Bharadwaj
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