On Wed, 2008-06-18 at 15:29 +1000, Paul Mackerras wrote: > At present, if we have a kernel with a 64kB page size, and some > process maps something that has to be mapped with 4kB pages (such as a > cache-inhibited mapping on POWER5+, or the eHCA infiniband queue-pair > pages), we change the process to use 4kB pages everywhere. This hurts > the performance of HPC programs that access eHCA from userspace. > > With this patch, the kernel will only demote the slice(s) containing > the eHCA or cache-inhibited mappings, leaving the remaining slices > able to use 64kB hardware pages. > > This also changes the slice_get_unmapped_area code so that it is > willing to place a 64k-page mapping into (or across) a 4k-page slice > if there is no better alternative, i.e. if the program specified > MAP_FIXED or if there is not sufficient space available in slices that > are either empty or already have 64k-page mappings in them. > > Signed-off-by: Paul Mackerras <[EMAIL PROTECTED]> > ---
Acked-by: Benjamin Herrenschmidt <[EMAIL PROTECTED]> (pending some torture testing of course :-) Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
