On Thu, Jan 24, 2019 at 01:17:18AM -0500, Chris Down wrote: > memcg has a significant number of files exposed to kernfs where their > value is either exposed directly or is "max" in the case of > PAGE_COUNTER_MAX. > > There's a fair amount of duplicated code here, since each file involves > turning a seq_file to a css, getting the memcg from the css, safely > reading the counter value, and then doing the right thing depending on > whether the value is PAGE_COUNTER_MAX or not. > > This patch adds the macro DEFINE_MEMCG_MAX_OR_VAL, which defines and > implements a generic way to do this work, avoiding fragmenting logic. > > Signed-off-by: Chris Down <chris@xxxxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: Roman Gushchin <guro@xxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: cgroups@xxxxxxxxxxxxxxx > Cc: linux-mm@xxxxxxxxx > Cc: kernel-team@xxxxxx > --- > mm/memcontrol.c | 78 ++++++++++++------------------------------------- > 1 file changed, 18 insertions(+), 60 deletions(-) I think this increases complexity more than it saves LOC, unfortunately. The current situation is a bit repetitive, but much more obviously correct. And we're not planning on adding many more of those memcg interface files, so I this doesn't seem to be an improvement re: maintainability and future extensibility of the code.
