Our service notices some hosts having large anon pages like these from pmap -x:
0000000580000000 9486088 9479172 9479172 rw— [ anon ]
meanwhile, our other regular hosts have much smaller anon pages like
0000000580000000 9486176 5730788 5730788 rw— [ anon ]
What possibly creates such large blocks?
I’ve tried heap dumping the process but the resulting heaps are about the same size. The difference in AnonPages account for ~3 gigs of extra memory the process uses.