On Friday 01 August 2008, Misbah khan wrote: > > Hi all, > > I have a DSP algorithm which i am running in the application even after > enabling the VFP support it is taking a lot of time to get executed hence > > I want to transform the same into the driver insted of an user application. > Can anybody suggest whether doing the same could be a better solution and > what could be the chalenges that i have to face by implimenting such > floating point support in the driver. > > Is there a way in the application itself to make it execute faster.
Floating-point in the kernel should be avoided. FPU state save/restore operations are costly and are not performed by the kernel when switching from userspace to kernelspace context. You will have to protect floating-point sections with kernel_fpu_begin/kernel_fpu_end which, if I'm not mistaken, disables preemption. That's probably not something you want to do. Why would the same code run faster in kernelspace then userspace ? -- Laurent Pinchart CSE Semaphore Belgium Chaussee de Bruxelles, 732A B-1410 Waterloo Belgium T +32 (2) 387 42 59 F +32 (2) 387 42 75
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