Messages in this thread Patch in this message | | | Date | Thu, 19 Jul 2018 13:10:31 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 1/2] mm: Keep int fields in struct shrink_control together |
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On Thu 19-07-18 13:51:19, Kirill Tkhai wrote: > gfp_t is of unsigned type, so let's move nid to keep > them together.
I guess you meant unsigned int so you can fill up a hole in shrink_control and as such reduce the stack consumption a bit (at least on 64b).
An output from pahole is usually a great tool to visualize this.
die__process_function: tag not supported (INVALID)! struct shrink_control { gfp_t gfp_mask; /* 0 4 */
/* XXX 4 bytes hole, try to pack */
long unsigned int nr_to_scan; /* 8 8 */ long unsigned int nr_scanned; /* 16 8 */ int nid; /* 24 4 */
/* XXX 4 bytes hole, try to pack */
struct mem_cgroup * memcg; /* 32 8 */
/* size: 40, cachelines: 1, members: 5 */ /* sum members: 32, holes: 2, sum holes: 8 */ /* last cacheline: 40 bytes */ };
> > Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> --- > include/linux/shrinker.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h > index b154fd2b084c..d58aaaed34a4 100644 > --- a/include/linux/shrinker.h > +++ b/include/linux/shrinker.h > @@ -12,6 +12,9 @@ > struct shrink_control { > gfp_t gfp_mask; > > + /* current node being shrunk (for NUMA aware shrinkers) */ > + int nid; > + > /* > * How many objects scan_objects should scan and try to reclaim. > * This is reset before every call, so it is safe for callees > @@ -26,9 +29,6 @@ struct shrink_control { > */ > unsigned long nr_scanned; > > - /* current node being shrunk (for NUMA aware shrinkers) */ > - int nid; > - > /* current memcg being shrunk (for memcg aware shrinkers) */ > struct mem_cgroup *memcg; > };
-- Michal Hocko SUSE Labs
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