mm: reduce noise in show_mem for lowmem allocations

mm: reduce noise in show_mem for lowmem allocations

While discussing early DMA pool pre-allocation failure with Christoph [1]
I have realized that the allocation failure warning is rather noisy for
constrained allocations like GFP_DMA{32}.  Those zones are usually not
populated on all nodes very often as their memory ranges are constrained.

This is an attempt to reduce the ballast that doesn't provide any relevant
information for those allocation failures investigation.  Please note that
I have only compile tested it (in my default config setup) and I am
throwing it mostly to see what people think about it.

[1] http://lkml.kernel.org/r/20220817060647.1032426-1-hch@lst.de

Link: https://lkml.kernel.org/r/YwScVmVofIZkopkF@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>