Date: Sat, 06 Oct 2018 07:59:57 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 229764] Default settings allow system to wire all ram Message-ID: <bug-229764-227-9MoxdAEhqU@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-229764-227@https.bugs.freebsd.org/bugzilla/> References: <bug-229764-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=229764 --- Comment #2 from Shane <FreeBSD@ShaneWare.Biz> --- (In reply to Andriy Gapon from comment #1) I'm not looking to change anything as memory is being allocated, I'm only looking at the sysctl settings, specifically arc_max being limited. Initially the default settings but also when assigning a new value. Currently we have defaults and allow assigning values that let a system get into a non-responsive state. On a machine with 8GB of physical RAM, max_wired is 2.4GB and arc_max is 7GB - that's RAM minus 1GB, so out of the box an 8GB system is allowed to wire more than 9GB, well maybe not allowed but two unrelated areas assuming they can allocate. I know from experience that a system with 8GB that has over 7GB wired only responds to the reset button. In this configuration, I expect sysctl should prevent arc_max being more than 5GB. If max_wired is only user wired allocations, then kernel wiring is another factor to be added into the equation. So initally, as max_wired is 30% of RAM, the default arc_max should not be set higher than 70% of RAM. When sysctl assigns a new value to arc_max the physical RAM and max_wired (and kernel wiring?) should be considered to check if the new value would allow the total wired RAM to be too high. -- You are receiving this mail because: You are the assignee for the bug.
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