Messages in this thread | | | Date | Sun, 24 Feb 2008 08:29:32 -0800 | From | "Siddha, Suresh B" <> | Subject | Re: [patch 1/2] x86,fpu: split FPU state from task struct |
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On Sun, Feb 24, 2008 at 08:27:30AM +0100, Roger While wrote: > > On Sat, Feb 23, 2008 at 06:34:38PM -0800, Suresh Siddha wrote: > > Split the FPU save area from the task struct. This allows easy migration > > of FPU context, and it's generally cleaner. It also allows the following > > two optimizations: > > > > 1) only allocate when the application actually uses FPU, so in the first > > lazy FPU trap. This could save memory for non-fpu using apps. Next patch > > does this lazy allocation. > > > > 2) allocate the right size for the actual cpu rather than 512 bytes > always. > > Patches enabling xsave/xrstor support (coming shortly) will take advantage > > of this. > > > if (next_p->fpu_counter>5) > > - prefetch(&next->i387.fxsave); > > + prefetch(FXSAVE(next_p)); > > Shouldn't that be prefetch(FXSAVE(next)); ?
No. 'next_p' which is the task_struct is what FXSAVE macro takes.
thanks, suresh
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