• SeongJae Park's avatar
    mm/damon/sysfs: handle 'state' file inputs for every sampling interval if possible · 6a080670
    SeongJae Park authored
    DAMON sysfs interface need to access kdamond-touching data for some of
    kdamond user commands.  It uses ->after_aggregation() kdamond callback to
    safely access the data in the case.  It had to use the aggregation
    interval callback because that was the only callback that users can access
    complete monitoring results.
    
    Since patch series "mm/damon: provide pseudo-moving sum based access
    rate", which starts from commit 78fbfb15 ("mm/damon/core: define and
    use a dedicated function for region access rate update"), DAMON provides
    good-to-use quality moitoring results for every sampling interval.  It
    aims to help users who need to quickly retrieve the monitoring results. 
    When the aggregation interval is set too long and therefore waiting for
    the aggregation interval can degrade user experience, or when the access
    pattern is expected to be significantly changed[1] could be such cases.
    
    However, because DAMON sysfs interface is still handling the commands per
    aggregation interval, the end user cannot get the benefit.  Update DAMON
    sysfs interface to handle kdamond commands for every sampling interval if
    applicable.  Specifically, all kdamond data accessing commands except
    'commit' command are applicable.
    
    [1] https://lore.kernel.org/r/20240129121316.GA9706@cuiyangpei
    
    Link: https://lkml.kernel.org/r/20240206025158.203097-1-sj@kernel.orgSigned-off-by: default avatarSeongJae Park <sj@kernel.org>
    Cc: xiongping1 <xiongping1@xiaomi.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    6a080670
sysfs-common.h 1.58 KB