From a2767cfb1d9d97c3f861743f1ad595a80b75ec99 Mon Sep 17 00:00:00 2001 From: Matt Fleming <matt@console-pimps.org> Date: Tue, 6 Oct 2009 21:22:34 +0000 Subject: sh: Don't allocate smaller sized mappings on every iteration Currently, we've got the less than ideal situation where if we need to allocate a 256MB mapping we'll allocate four entries like so, entry 1: 128MB entry 2: 64MB entry 3: 16MB entry 4: 16MB This is because as we execute the loop in pmb_remap() we will progressively try mapping the remaining address space with smaller and smaller sizes. This isn't good because the size we use on one iteration may be the perfect size to use on the next iteration, for instance when the initial size is divisible by one of the PMB mapping sizes. With this patch, we now only need two entries in the PMB to map 256MB of address space, entry 1: 128MB entry 2: 128MB Signed-off-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org> --- arch/sh/mm/pmb.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c index 58f935896b44..aade31102112 100644 --- a/arch/sh/mm/pmb.c +++ b/arch/sh/mm/pmb.c @@ -269,6 +269,13 @@ again: pmbp->link = pmbe; pmbp = pmbe; + + /* + * Instead of trying smaller sizes on every iteration + * (even if we succeed in allocating space), try using + * pmb_sizes[i].size again. + */ + i--; } if (size >= 0x1000000) -- cgit v1.2.2