On Mon, Aug 06, 2018 at 11:07:40AM -0700, Andi Kleen wrote: > On Mon, Aug 06, 2018 at 03:17:44PM +0200, Vasily Gorbik wrote: > > Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount > > compiler flag support is tested for every Makefile. > > Good catch. Does it make a measurable compile time difference? >
A bit more than couple of seconds, but it does make a difference for a delta build: with patch: real 0m9.405s user 0m6.966s sys 0m2.287s without: real 0m12.153s user 0m9.058s sys 0m3.026s with -j48 on s390 24 cores lpar: with patch: real 0m1.949s user 0m7.034s sys 0m2.400s without: real 0m2.255s user 0m9.243s sys 0m3.266s > > > > Top 4 cc-option usages: > > 511 -mrecord-mcount
