On Mon, 22 Jul 2024, Vlastimil Babka (SUSE) wrote: > On 7/6/24 10:55 PM, David Rientjes wrote: > > Hi all, > > > > I'm trying to crowdsource information on open source tools that can be > > used directly by customers to explain memory mappings, usage, pressure, > > etc. > > > > We encounter both internal and external users that are looking for this > > insight and it often requires significant engineering time to collect data > > to make any conclusions. > > > > A recent example is an external customer that recently upgraded their > > userspace and started to run into memcg constrained memory pressure that > > wasn't previously observed. After handing off a hacky script to run in > > the background, it was immediately obvious that the source of the direct > > reclaim was all of the MADV_FREE memory that was sitting around. > > Converting to MADV_DONTNEED solved their issue. > > BTW, was this reported/fixed upstream? Sounds like a bug to me that would > better be fixed than suggesting the MADV_DONTNEED workaround to everyone > from now on. >
