On Fri 18-12-20 18:22:17, Jacob Wen wrote:
> This patch reduces repetition of set_task_reclaim_state() around
> do_try_to_free_pages().
The changelog really should be talking about why this is needed/useful.
>From the above it is not really clear whether you aimed at doing
a clean up or this is a fix for some misbehavior. I do assume the former
but this should be clearly articulated.
> Signed-off-by: Jacob Wen <jian.w....@oracle.com>
> ---
> mm/vmscan.c | 27 ++++++++++++++++-----------
> 1 file changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 257cba79a96d..4bc244b23686 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -3023,6 +3023,10 @@ static unsigned long do_try_to_free_pages(struct
> zonelist *zonelist,
> pg_data_t *last_pgdat;
> struct zoneref *z;
> struct zone *zone;
> + unsigned long ret;
> +
> + set_task_reclaim_state(current, &sc->reclaim_state);
> +
> retry:
> delayacct_freepages_start();
>
> @@ -3069,12 +3073,16 @@ static unsigned long do_try_to_free_pages(struct
> zonelist *zonelist,
>
> delayacct_freepages_end();
>
> - if (sc->nr_reclaimed)
> - return sc->nr_reclaimed;
> + if (sc->nr_reclaimed) {
> + ret = sc->nr_reclaimed;
> + goto out;
> + }
>
> /* Aborted reclaim to try compaction? don't OOM, then */
> - if (sc->compaction_ready)
> - return 1;
> + if (sc->compaction_ready) {
> + ret = 1;
> + goto out;
> + }
>
> /*
> * We make inactive:active ratio decisions based on the node's
> @@ -3101,7 +3109,10 @@ static unsigned long do_try_to_free_pages(struct
> zonelist *zonelist,
> goto retry;
> }
>
> - return 0;
> + ret = 0;
> +out:
> + set_task_reclaim_state(current, NULL);
> + return ret;
> }
>
> static bool allow_direct_reclaim(pg_data_t *pgdat)
> @@ -3269,13 +3280,11 @@ unsigned long try_to_free_pages(struct zonelist
> *zonelist, int order,
> if (throttle_direct_reclaim(sc.gfp_mask, zonelist, nodemask))
> return 1;
>
> - set_task_reclaim_state(current, &sc.reclaim_state);
> trace_mm_vmscan_direct_reclaim_begin(order, sc.gfp_mask);
>
> nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
>
> trace_mm_vmscan_direct_reclaim_end(nr_reclaimed);
> - set_task_reclaim_state(current, NULL);
>
> return nr_reclaimed;
> }
> @@ -3347,7 +3356,6 @@ unsigned long try_to_free_mem_cgroup_pages(struct
> mem_cgroup *memcg,
> */
> struct zonelist *zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);
>
> - set_task_reclaim_state(current, &sc.reclaim_state);
> trace_mm_vmscan_memcg_reclaim_begin(0, sc.gfp_mask);
> noreclaim_flag = memalloc_noreclaim_save();
>
> @@ -3355,7 +3363,6 @@ unsigned long try_to_free_mem_cgroup_pages(struct
> mem_cgroup *memcg,
>
> memalloc_noreclaim_restore(noreclaim_flag);
> trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed);
> - set_task_reclaim_state(current, NULL);
>
> return nr_reclaimed;
> }
> @@ -4023,11 +4030,9 @@ unsigned long shrink_all_memory(unsigned long
> nr_to_reclaim)
>
> fs_reclaim_acquire(sc.gfp_mask);
> noreclaim_flag = memalloc_noreclaim_save();
> - set_task_reclaim_state(current, &sc.reclaim_state);
>
> nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
>
> - set_task_reclaim_state(current, NULL);
> memalloc_noreclaim_restore(noreclaim_flag);
> fs_reclaim_release(sc.gfp_mask);
>
> --
> 2.25.1
>
--
Michal Hocko
SUSE Labs
