On Wed, Apr 05, 2023 at 06:01:07PM +0700, Shaun Tancheff wrote: > From: Shaun Tancheff <shaun.tancheff@xxxxxxx> > > For users that are unable to update to memcg-v2 this > provides a method where memcg-v1 can more effectively > apply enough memory pressure to effectively throttle > filesystem I/O or otherwise minimize being memcg oom > killed at the expense of reduced performance. > > This patch extends the memcg-v1 legacy sysfs entries > with: > limit_in_bytes.min, limit_in_bytes.low and > limit_in_bytes.high > Since old software will need to be updated to take > advantage of the new files a secondary method > of setting min, low and high based on a percentage > of the limit is also provided. The percentages > are determined by module parameters. > > The available module parameters can be set at > kernel boot time, for example: > memcontrol.memcg_min=10 > memcontrol.memcg_low=30 > memcontrol.memcg_high=80 > > Would set min to 10%, low to 30% and high to 80% of > the value written to: > /sys/fs/cgroup/memory/<grp>/memory.limit_in_bytes > > Signed-off-by: Shaun Tancheff <shaun.tancheff@xxxxxxx> > --- > v0: Initial hard coded limits by percent. > v1: Added sysfs access and module parameters for percent values to enable > v2: Fix 32-bit, remove need for missing __udivdi3 > mm/memcontrol.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 82 insertions(+), 1 deletion(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 2eee092f8f11..3cf8386f4f45 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -73,6 +73,18 @@ > > #include <trace/events/vmscan.h> > > +static unsigned int memcg_v1_min_default_percent; > +module_param_named(memcg_min, memcg_v1_min_default_percent, uint, 0600); > +MODULE_PARM_DESC(memcg_min, "memcg v1 min default percent"); > + > +static unsigned int memcg_v1_low_default_percent; > +module_param_named(memcg_low, memcg_v1_low_default_percent, uint, 0600); > +MODULE_PARM_DESC(memcg_low, "memcg v1 low default percent"); > + > +static unsigned int memcg_v1_high_default_percent; > +module_param_named(memcg_high, memcg_v1_high_default_percent, uint, 0600); > +MODULE_PARM_DESC(memcg_high, "memcg v1 high default percent"); This is not the 1990's, why are you using module parameters for this? And this isn't a module, so why use module options, how are you supposed to set them? And you didn't document them anywhere? Also, why is this cc: stable? thanks, greg k-h
