On Wed, May 27, 2020 at 2:31 PM Arnd Bergmann <a...@arndb.de> wrote: > > On Wed, May 27, 2020 at 1:36 PM Sedat Dilek <sedat.di...@gmail.com> wrote: > > On Wed, May 27, 2020 at 1:27 PM Arnd Bergmann <a...@arndb.de> wrote: > > > On Wed, May 27, 2020 at 12:33 PM Marco Elver <el...@google.com> wrote: > > > > > > This gives us back 80% of the performance drop on clang, and 50% > > > of the drop I saw with gcc, compared to current mainline. > > > > > > Tested-by: Arnd Bergmann <a...@arndb.de> > > > > > > > Hi Arnd, > > > > with "mainline" you mean Linux-next aka Linux v5.8 - not v5.7? > > I meant v5.7. > > > I have not seen __unqual_scalar_typeof(x) in compiler_types.h in Linux v5.7. > > > > Is there a speedup benefit also for Linux v5.7? > > Which patches do I need? > > v5.7-rc is the baseline and is the fastest I currently see. On certain files, > I saw an intermittent 10x slowdown that was already fixed earlier, now > linux-next > is more like 2x slowdown for me and 1.2x with this patch on top, so we're > almost back to the speed of linux-5.7. >
Which clang version did you use - and have you set KCSAN kconfigs - AFAICS this needs clang-11? - Sedat -