Messages in this thread | | | Date | Tue, 15 Sep 2009 16:07:05 -0700 | Subject | Re: [PATCH 21/29] ioat2,3: dynamically resize descriptor ring | From | Dan Williams <> |
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On Mon, Sep 14, 2009 at 8:00 AM, Sosnowski, Maciej <maciej.sosnowski@intel.com> wrote: > Making the max_alloc_order a module parameter gives impression > that it can be modified by an user, including making it larger than default. > The default is however its maximum value, which may be confusing. > Why not to use parameter only as the upper limit?
It is the upper limit.
The user can limit the upper size of the descriptor ring by setting this to a value less than 16. By default it is the maximum ring size that the driver/hardware* supports. Specifying values greater than 16 are not supported by the so we need enforce a ceiling at 16.
-- Dan
* We could support ring sizes larger than 1 << 16 but we would need to extra logic to ensure that the pending count never exceeded 1 << 16. Simpler I think to just limit the maximum ring size.
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