This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: malloc: Trim unused arenas on thread exit


On 11/13/2017 10:57 PM, DJ Delorie wrote:
Florian Weimer <fweimer@redhat.com> writes:
I think trimming unused arenas as much as possible is a good heuristics
to minimize RSS, so getting this to work might be worthwhile.

I ran this against many of my real-world workloads and did not see a
significant (i.e. obvious) reduction in actual RSS.  Some tests showed a
minor (i.e. untrustworthy, I didn't run enough passes to reduce the
noise below any measured change) *increase* in RSS, as well as an
expected (but still untrustworthy) increase in cycles required.

Sorry, as I tried to say in my original message: It does not actually reuse RSS because the sub-heaps are not deallocated. I don't know why this does not happen.

The trimming really should be a win because the workload is likely to change when a thread exits.

Thanks,
Florian


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]