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Re: bus_dmamap_destroy no longer callable from interrupt context?



On 11/15/2013 07:59 PM, Matt Thomas wrote:
> 
> On Nov 15, 2013, at 10:56 AM, Lars Heidieker <lars%heidieker.de@localhost> 
> wrote:
> 
>> Matt, you mean allocating and freeing memory from softint context should
>> be ok? That's something that went through my mind as well and I think
>> it's the right way.
> 
> I do.  softint routines can wait for mutexes so allocation in them should
> be safe.  Adding the complexity of needing a "real" thread context to do
> safe allocations seems more prone to problems.
> 

a few month ago I looked at some allocations in oder to change them to
thread context and a lot of them are like allocating from thread context
and freeing from softint context.
eg  wapbl_entry_pool in wapbl_entry_pool and those pools used for USB
ehcixfer uhcixfer etc fall into the same category if I remember right.

I came to the same conclusion that a lot complexity and a lot of custom
code for these allocation would be required to move them to thread
context and installing a special pool for each allocation is a lot of
overhead as well and doesn't fill the bill.

Lars



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