I notice that when, the system runs out of space and we are trying to get a live core dump there is delay of around 30 minutes to return ENOSPC to the upper layers. This is on AMD64. As I go through the code , I see a change to the amd64 not present in other platforms in sys/amd64/amd64/minidump_machdep.c . Its the retry count set to 5 ( Not sure where that number comes from ). Because of this, the live core generation in our platform is delayed and the memory map keeps increasing( lots of other stuff running ) it makes things worse. I want to make this retry count a tunable so that it can be changed at runtime accordingly.
Please check this review https://reviews.freebsd.org/D8254
please review this https://reviews.freebsd.org/D8254
A commit references this bug: Author: stevek Date: Mon Oct 17 22:57:41 UTC 2016 New revision: 307540 URL: https://svnweb.freebsd.org/changeset/base/307540 Log: Add sysctl to make amd64 minidump retry count tunable at runtime. PR: 213462 Submitted by: RaviPrakash Darbha <rdarbha@juniper.net> Reviewed by: cemi, markj Approved by: sjg (mentor) Obtained from: Juniper Networks Differential Revision: https://reviews.freebsd.org/D8254 Changes: head/sys/amd64/amd64/minidump_machdep.c