On Fri, 5 Aug 2022 17:04:28 -0700 Roman Gushchin <roman.gushchin@xxxxxxxxx> wrote: > On Fri, Aug 05, 2022 at 04:32:34PM -0700, Linus Torvalds wrote: > > On Wed, Aug 3, 2022 at 1:35 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > - memcg debug/visibility work from Roman Gushchin > > > > Well, not just memcg. > > > > There's that new CONFIG_SHRINKER_DEBUG too. > > > > Which looks like yet another "people add Kconfig options incorrectly". > > > > We don't make new features "default y" unless there's some truly > > pressing reason for it (ie "99.9% of all people will want this" or "we > > used to always compile this in, now it's optional"). > > Hi Linus! > > It actually was 'default n' in one of the earlier version of the patchset > and has been switched to 'default y' based on the following feedback from > Dave Chinner (https://lore.kernel.org/lkml/YmiWK56bOHyrr64u@rh/): > > No. The argument that "if we turn it off there's no overhead" means > one of two things: > > 1. nobody turns it on and it never gets tested and so bitrots and is > useless, or > 2. distro's all turn it on because some tool they ship or customer > they ship to wants it. > > Either way, hiding it behind a config option is not an acceptible > solution for mering poorly thought out infrastructure. > > Personally I think that the feature is not that useful for the majority > of users (this is why default was n), but it's not adding much of the > overhead, so I had no strong reasons to oppose Dave. > Cc'ing him just in case. > We should have changelogged these considerations. I've asked Joe if checkpatch can get a "default y" detector, to draw attention to this in the future.
