On Thu, May 09, 2019 at 01:45:31PM -0500, Josh Poimboeuf wrote: > On Thu, May 09, 2019 at 02:29:02PM -0400, Steven Rostedt wrote: > > On Thu, 9 May 2019 09:51:59 -0700 > > Linus Torvalds <torva...@linux-foundation.org> wrote: > > > > > On Thu, May 9, 2019 at 6:01 AM Steven Rostedt <rost...@goodmis.org> wrote: > > > > > > > > This patch works. Can I get your Signed-off-by for it? > > > > > > Yes. Please write some kind of comprehensible commit log for it, but > > > > How's this: > > > > "Peter Zijlstra noticed that with CONFIG_PROFILE_ALL_BRANCHES, the "if" > > macro converts the conditional to an array index. This can cause GCC > > to create horrible code. When there are nested ifs, the generated code > > uses register values to encode branching decisions. > > > > Josh Poimboeuf found that replacing the define "if" macro from using > > the condition as an array index and incrementing the branch statics > > with an if statement itself, reduced the asm complexity and shrinks the > > generated code quite a bit. > > > > But this can be simplified even further by replacing the internal if > > statement with a ternary operator. > > > > Reported-by: Peter Zijlstra (Intel) <pet...@infradead.org> > > Reported-by: Josh Poimboeuf <jpoim...@redhat.com> > > Actually, my original fix already went in: > > 37686b1353cf ("tracing: Improve "if" macro code generation") > > But it introduced a regression: > > https://lkml.kernel.org/r/201905040509.iqq2crou%...@intel.com > > which Linus' patch fixes for some reason.
/me curses URL encoding https://lkml.kernel.org/r/201905040509.iqq2crou%25...@intel.com -- Josh