On Fri, 2009-11-20 at 11:00 +0800, Li Yang-R58472 wrote: > Because there is no way to set mapped memory as cacheable if the > memory > is not managed by Linux kernel. While, it's not rare in real system > to > allocate some dedicated memory to a certain application which is not > managed by kernel and then mmap'ed the memory to the application. The > memory should be cacheable but we can't map it to be cacheable due to > this intelligent setting. And it is a big hit to the performance. > Moreover, the standard O_SYNC flag suggest that user has the control > over cacheablity, but actually we had not.
You need to be a bit more careful tho. You must not allow RAM managed by the kernel to be mapped non-cachable. Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
