Re: [PATCH 4/4] x86: Use the page tables to look up kernel addresses in backtrace

On Fri, 2014-10-10 at 16:25 -0700, Andi Kleen wrote: > From: Andi Kleen > > On my workstation which has a lot of modules loaded: > > $ lsmod | wc -l > 80 > This patch uses the NX bits in the page tables to check for > valid kernel addresses instead. This can be done in any context > because ker

Re: [PATCH 4/4] x86: Use the page tables to look up kernel addresses in backtrace

On Fri, 10 Oct 2014 16:25:17 -0700 Andi Kleen wrote: > From: Andi Kleen > > On my workstation which has a lot of modules loaded: > > $ lsmod | wc -l > 80 > > backtrace from the NMI for perf record -g can take a quite long time. > > This leads to frequent messages like: > perf interrupt took