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From: Arnd Bergmann <arnd@arndb.de>
To: krishna <krishna.c@globaledgesoft.com>
Subject: Re: Documentation on top half and bottom halves
Date: Sat, 18 Dec 2004 15:08:53 +0100
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On S=FCnnavend 18 Dezember 2004 14:41, you wrote:
> How to understand when to use which mechanism depending upon the hardware:
>=20
> 1) If DMA support is not there and If it is there.
> 2) If Shared Interrupts are there and not there.
> 3) If there are multiple same Host controllers and single Host Controller.

It's independent of these questions. The decision between tasklet and
workqueue is mostly:

=2D If you need non-atomic operations (e.g. allocate memory with GFP_KERNEL=
),
  you have to use work queues.
=2D If you need very low latencies for processing the interrupts, you should
  use tasklets.
=2D When in doubt, use work queues.

 Arnd <><

PS: pleas read http://www.netmeister.org/news/learn2quote.html

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