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From: Kent Overstreet <kent.overstreet@linux.dev>
Subject: Re: [PATCH 00/40] Memory allocation profiling
Date: Wed, 3 May 2023 14:56:44 -0400
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To: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.com>, Suren Baghdasaryan <surenb@google.com>, akpm@linux-foundation.org, vbabka@suse.cz, roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, corbet@lwn.net, void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com, ldufour@linux.ibm.com, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, dennis@kernel.org, muchun.song@linux.dev, rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com, yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.c

On Wed, May 03, 2023 at 08:40:07AM -1000, Tejun Heo wrote:
> > Yeah, easy / default visibility argument does make sense to me.
> 
> So, a bit of addition here. If this is the thrust, the debugfs part seems
> rather redundant, right? That's trivially obtainable with tracing / bpf and
> in a more flexible and performant manner. Also, are we happy with recording
> just single depth for persistent tracking?

Not sure what you're envisioning?

I'd consider the debugfs interface pretty integral; it's much more
discoverable for users, and it's hardly any code out of the whole
patchset.

Single depth was discussed previously. It's what makes it cheap enough
to be always-on (saving stack traces is expensive!), and I find the
output much more usable than e.g. page owner.