Re: [PATCH] mm/slub: Detach node lock from counting free objects

[Andrew Morton]

On Sat, 8 Feb 2020 21:41:49 +0000 (UTC) Christopher Lameter <cl@xxxxxxxxx> wrote:

> On Sat, 8 Feb 2020, Wen Yang wrote:
> 
> > I would greatly appreciate it if you kindly give me some feedback on this
> > patch.
> 
> I think the measure is too severe given its use and the general impact on code.

Severe in what way?  It's really a quite simple change, although quite
a few edits were needed.

> Maybe avoid taking the lock or reducing the time a lock is taken when reading /proc/slabinfo is
> the best approach?
> 
> Also you could cache the value in the userspace application? Why is this
> value read continually?

: reading "/proc/slabinfo" can possibly block the slab allocation on
: another CPU for a while, 200ms in extreme cases

That was bad of us.  It would be good to stop doing this.