RFR(S): 8186286: [BSD] Primary thread's stack size is reported incorrectly

[Haug, Gunter]

Thanks for the review, Aleksey and Thomas

You’re right, it is much nicer to use the macros. I’ve updated the change accordingly:
http://cr.openjdk.java.net/~ghaug/webrevs/8186286.v1

@Thomas: os::vm_page_size() is not used in current_stack_region(), I think because of initialization dependencies.

Best regards,
Gunter

From: Thomas Stüfe <thomas.stuefe at gmail.com>
Date: Thursday, 17. August 2017 at 15:06
To: "Haug, Gunter" <gunter.haug at sap.com>
Cc: "hotspot-dev at openjdk.java.net" <hotspot-dev at openjdk.java.net>
Subject: Re: RFR(S): 8186286: [BSD] Primary thread's stack size is reported incorrectly

Hi Gunter,


On Thu, Aug 17, 2017 at 2:24 PM, Haug, Gunter <gunter.haug at sap.com<mailto:gunter.haug at sap.com>> wrote:
Hi,

can I please have reviews and a sponsor fort the following small bug fix:
http://cr.openjdk.java.net/~ghaug/webrevs/8186286/
https://bugs.openjdk.java.net/browse/JDK-8186286

At least on Mac OS 10.12 we have observed stack sizes of the primary thread not aligned to pages boundries. This can be provoked by e.g. setrlimit() (ulimit -s xxxx in the shell).This voids the computation of the addresses of the guard pages.

Fix:
Apparently Mac OS actually rounds upwards to next multiple of page size however, it is conservative to round downwards here to be on the safe side.

Thanks and best regards,
Gunter

Thanks for the patch!

Very minor nits: what Alexey wrote (we also have "is_aligned"). Plus, any reason not to use os::vm_page_size()? Initialization dependencies?

Kind Regards, Thomas