Messages in this thread | | | Date | Fri, 2 Oct 2020 11:19:52 +0100 | From | Mel Gorman <> | Subject | Re: [RFC-PATCH 2/4] mm: Add __rcu_alloc_page_lockless() func. |
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On Fri, Oct 02, 2020 at 11:58:58AM +0200, Peter Zijlstra wrote: > > It's enabled by default by enough distros that adding too many checks > > is potentially painful. Granted it would be missed by most benchmarking > > which tend to control allocations from userspace but a lot of performance > > problems I see are the "death by a thousand cuts" variety. > > Oh quite agreed, aka death by accounting. But if people are enabling > DEBUG options in production kernels, there's something wrong, no? >
You'd think but historically I believe DEBUG_VM was enabled for some distributions because it made certain classes of problems easier to debug early. There is also a recent trend for enabling various DEBUG options for "hardening" even when they protect very specific corner cases or are for intended for kernel development. I've pushed back where I have an opinion that matters but it's generally corrosive.
> Should we now go add CONFIG_REALLY_DEBUG_STAY_AWAY_ALREADY options?
It's heading in that direction :(
-- Mel Gorman SUSE Labs
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