On Sat, Aug 06, 2022 at 08:49:23AM +0200, Christophe JAILLET wrote: > Give a hint to the compiler that dev_err_probe() is used for error > handling. So calling paths are unlikely. > > >From gcc documentation: > The paths leading to calls of cold functions within code are marked > as unlikely by the branch prediction mechanism. > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> > --- > include/linux/device.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 424b55df0272..4ac16bde9bf7 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -1093,7 +1093,7 @@ void device_links_supplier_sync_state_pause(void); > void device_links_supplier_sync_state_resume(void); > > extern __printf(3, 4) > -int dev_err_probe(const struct device *dev, int err, const char *fmt, ...); > +int __cold dev_err_probe(const struct device *dev, int err, const char *fmt, ...); As the probe() path is by default "slow", does this actually help anything? I never recommend using any sort of manual likely/unlikely hints unless the results can be seen, otherwise the compiler and CPU almost always do a better job over time. thanks, greg k-h
