On Wed, Apr 05, 2023 at 08:54:07PM +0700, Shaun Tancheff wrote: > On Wed, Apr 5, 2023 at 6:23 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > 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? > > > Ah .. guess I'm a bit out of date. > The can be set either on the kernel command line or through sysfs, > nominally > /sys/module/memcontrol/parameters/memcg_high > /sys/module/memcontrol/parameters/memcg_low > /sys/module/memcontrol/parameters/memcg_min But again, memcontrol is not a module, right? > I will look at making these sysctl values instead. Yeah, just stick with that please. thanks, greg k-h
