x86, kdump: Change copy_oldmem_page() to use cached addressing
x86, kdump: Change copy_oldmem_page() to use cached addressing

The copy of /proc/vmcore to a user buffer proceeds much faster
if the kernel addresses memory as cached.

With this patch we have seen an increase in transfer rate from
less than 15MB/s to 80-460MB/s, depending on size of the
transfer. This makes a big difference in time needed to save a
system dump.

Signed-off-by: Cliff Wickman <ee7f92c2340d75c28a753294f7a9f57a3233aa67@sgi.com>
Acked-by: "Eric W. Biederman" <8a741aa8cbd77ebc4a56ddb528ce9fd15d42f034@xmission.com>
Cc: b5009a9f6c3d53321a47e34e76cc1e3dc8f59221@lists.infradead.org
Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@kernel.org> # as far back as it would apply
LKML-Reference: <13e2f337fa0a7bd60c75172bf5fba2418aef41a5@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas