mm, show_mem: remove SHOW_MEM_FILTER_PAGE_COUNT

Commit 4b59e6c47309 ("mm, show_mem: suppress page counts in
non-blockable contexts") introduced SHOW_MEM_FILTER_PAGE_COUNT to
suppress PFN walks on large memory machines.  Commit c78e93630d15 ("mm:
do not walk all of system memory during show_mem") avoided a PFN walk in
the generic show_mem helper which removes the requirement for
SHOW_MEM_FILTER_PAGE_COUNT in that case.

This patch removes PFN walkers from the arch-specific implementations
that report on a per-node or per-zone granularity.  ARM and unicore32
still do a PFN walk as they report memory usage on each bank which is a
much finer granularity where the debugging information may still be of
use.  As the remaining arches doing PFN walks have relatively small
amounts of memory, this patch simply removes SHOW_MEM_FILTER_PAGE_COUNT.

[akpm@linux-foundation.org: fix parisc]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 7 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 89d81f4429ca..ec4417cb458a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2072,13 +2072,6 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
                 return;
 
         /*
-         * Walking all memory to count page types is very expensive and should
-         * be inhibited in non-blockable contexts.
-         */
-        if (!(gfp_mask & __GFP_WAIT))
-                filter |= SHOW_MEM_FILTER_PAGE_COUNT;
-
-        /*
          * This documents exceptions given to allocations in certain
          * contexts that are allowed to allocate outside current's set
          * of allowed nodes.