Date: Sun, 3 Jan 2016 15:30:56 +0100 From: "Kristian A. Hiorth" <kah@kahnews.net> To: freebsd-hackers@freebsd.org Subject: Re: variables optimized out Message-ID: <568930A0.6010405@kahnews.net> In-Reply-To: <CAA99N-OKyxzVaJ4ayXRUGAoovNtHFXTpOXPkwhdw9k3LEMnOtw@mail.gmail.com> References: <CAA99N-OKyxzVaJ4ayXRUGAoovNtHFXTpOXPkwhdw9k3LEMnOtw@mail.gmail.com>
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On 01/03/2016 02:38 PM, robbinson defau wrote: > Hi all, > > Im debugging some issues in the kernel and as the kernel is compiled by > default with -O2, a lot of variables are optimized out. So i made changes > to make.conf (CFLAGS and COPTFLAGS).\ > > All builds fine, but I get the weirdest of panics that most certainly not > happen with -O2. So it's likely i'm doing something wrong. What would be > the correct way to be able to debug the kernel and have it build such that > locals and function arguments are not optimized out? > > Thanks in advance, > > /DF Hi, sounds like stack overflows, did you try increasing kernel stack size? Stuff like WITNESS causes a lot of stack growth when the optimizer inlines fewer calls. I've run an -O0 kernel with options KSTACK_PAGES=6 without too many problems. Hope this helps, Kristian
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