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Michal Hocko
93b3a67448
pagetypeinfo_showfree_print is called by zone->lock held in irq mode. This is not really nice because it blocks both any interrupts on that cpu and the page allocator. On large machines this might even trigger the hard lockup detector. Considering the pagetypeinfo is a debugging tool we do not really need exact numbers here. The primary reason to look at the outuput is to see how pageblocks are spread among different migratetypes and low number of pages is much more interesting therefore putting a bound on the number of pages on the free_list sounds like a reasonable tradeoff. The new output will simply tell [...] Node 6, zone Normal, type Movable >100000 >100000 >100000 >100000 41019 31560 23996 10054 3229 983 648 instead of Node 6, zone Normal, type Movable 399568 294127 221558 102119 41019 31560 23996 10054 3229 983 648 The limit has been chosen arbitrary and it is a subject of a future change should there be a need for that. While we are at it, also drop the zone lock after each free_list iteration which will help with the IRQ and page allocator responsiveness even further as the IRQ lock held time is always bound to those 100k pages. [[email protected]: tweak comment text, per David Hildenbrand] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Michal Hocko <[email protected]> Suggested-by: Andrew Morton <[email protected]> Reviewed-by: Waiman Long <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Acked-by: David Hildenbrand <[email protected]> Acked-by: Rafael Aquini <[email protected]> Acked-by: David Rientjes <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Jann Horn <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Konstantin Khlebnikov <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Song Liu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.