On Wed, Jan 24, 2018 at 06:25:01PM +0100, Tomas Vondra wrote: > > > > I think there there are two things to consider - aset.c and glibc. > > In AllocSet this is handled as over-sized chunk, that is chunk greater > than ALLOC_CHUNK_LIMIT (which ends up being 8kB). Which means it's > allocated as a separate block, and does not go through the freelists. So > the size does not follow the usual "power of 2" pattern and is only > maxalign-ed, and then freed immediately on pfree. > > So for AllocSet we're fine, and this should not result in any memory > inefficiency, assuming there are not many such requests (which would > result in many malloc/free calls, which may be somewhat expensive). > > At the glibc level ... I'm not so sure. AFAIK glibc uses an allocator > with similar ideas (freelists, ...) so hopefully it's fine too. > > And then there are the systems without glibc, or with other libc > implementations. No idea about those.
Thanks for the analysis. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription +
