I may be wrong but I think the Guarded Page facility is about load references. This could e.g. help Java to determine hot versus cold objects without generating too much overhead. As such it could therewith also assist determining the active working set ... but in the end the question remains how stable such working set is, and whether it exists as subset to the virtual machine allocation in the first place ...
Best regards Ingo Linux on 390 Port <LINUX-390@VM.MARIST.EDU> wrote on 18/08/2020 16:03:30: > From: Neale Ferguson <ne...@sinenomine.net> > To: LINUX-390@VM.MARIST.EDU > Date: 18/08/2020 16:03 > Subject: [EXTERNAL] Re: [LINUX-390] vmrelocate and quiescence time > Sent by: Linux on 390 Port <LINUX-390@VM.MARIST.EDU> > > Could you take advantage of the guard page hardware facility of the > z15 that the pause-less Java garbage collector uses? > > -------- Original message -------- > > z/VM doesn't have a short cut to determine that no pages have changed. So > for a guest over 100GB, it has to examine over 26 million things multiple > times. Validating the I/O is drained is another aspect, but my guess is the > traversing of the DAT structures is the biggest factor. > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit > INVALID URI REMOVED > u=http-3A__www2.marist.edu_htbin_wlvindex-3FLINUX-2D390&d=DwIGaQ&c=jf_iaSHvJObTbx- > siA1ZOg&r=jQ4IiHbzZ0l-wFKuUHMHvPIsi5vD8MZZCyI-y49pWL0&m=MK- > gQWB799b9yN6buzqOhh1pAPxzHhfZFTMynpjO- > H8&s=P75LMSRd_VThN0H8mYgUsmax8xHEBmq_CeYJ5NvxiuA&e= > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www2.marist.edu/htbin/wlvindex?LINUX-390
