Re: [tip:timers/core] time: Move timeconst.h into include/generated

Nicholas Mc Guire
2015-06-30T06:52:55Z

On Mon, 29 Jun 2015, Stephen Boyd wrote:

> On 05/19/2015 06:36 AM, tip-bot for Nicholas Mc Guire wrote:
> > Commit-ID: 0a227985d4a993a322ff72ecbaeee2611d624216
> > Gitweb: http://git.kernel.org/tip/0a227985d4a993a322ff72ecbaeee2611d624216
> > Author: Nicholas Mc Guire <hofrat@osadl.org>
> > AuthorDate: Mon, 18 May 2015 14:19:12 +0200
> > Committer: Thomas Gleixner <tglx@linutronix.de>
> > CommitDate: Tue, 19 May 2015 15:13:45 +0200
> >
> > time: Move timeconst.h into include/generated
> >
> > kernel/time/timeconst.h is moved to include/generated/ and generated
> > by the top level Kbuild. This allows using timeconst.h in an earlier
> > build stage.
> >
> > Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
> > Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
> > Cc: Sam Ravnborg <sam@ravnborg.org>
> > Cc: Joe Perches <joe@perches.com>
> > Cc: John Stultz <john.stultz@linaro.org>
> > Cc: Andrew Hunter <ahh@google.com>
> > Cc: Paul Turner <pjt@google.com>
> > Cc: Michal Marek <mmarek@suse.cz>
> > Link: http://lkml.kernel.org/r/1431951554-5563-1-git-send-email-hofrat@osadl.org
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > ---
>
> This patch seems to cause kernel/time/time.c to always need to be
> recompiled and the vmlinux to be relinked even if nothing has changed.
>
> make V=2 shows
>
> CC kernel/time/time.o - due to: include/config/
>
>
> > diff --git a/Kbuild b/Kbuild
> > index 6f0d82a..df99a5f 100644
> > --- a/Kbuild
> > +++ b/Kbuild
> > @@ -2,8 +2,9 @@
> > # Kbuild for top-level directory of the kernel
> > # This file takes care of the following:
> > # 1) Generate bounds.h
> > -# 2) Generate asm-offsets.h (may need bounds.h)
> > -# 3) Check for missing system calls
> > +# 2) Generate timeconst.h
> > +# 3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
> > +# 4) Check for missing system calls
> >
> > # Default sed regexp - multiline due to syntax constraints
> > define sed-y
> > @@ -47,7 +48,26 @@ $(obj)/$(bounds-file): kernel/bounds.s FORCE
> > $(call filechk,offsets,__LINUX_BOUNDS_H__)
> >
> > #####
> > -# 2) Generate asm-offsets.h
> > +# 2) Generate timeconst.h
> > +
> > +timeconst-file := include/generated/timeconst.h
> > +
> > +#always += $(timeconst-file)
>
> Is there a reason this is commented out instead of removed?

negligence on my side - should have been removed

>
> > +targets += $(timeconst-file)
> > +
> > +quiet_cmd_gentimeconst = GEN $@
> > +define cmd_gentimeconst
> > [...]
> > diff --git a/kernel/time/Makefile b/kernel/time/Makefile
> > index 01f0312..ffc4cc3 100644
> > --- a/kernel/time/Makefile
> > +++ b/kernel/time/Makefile
> > @@ -13,19 +13,4 @@ obj-$(CONFIG_TIMER_STATS) += timer_stats.o
> > obj-$(CONFIG_DEBUG_FS) += timekeeping_debug.o
> > obj-$(CONFIG_TEST_UDELAY) += test_udelay.o
> >
> > -$(obj)/time.o: $(obj)/timeconst.h
> > -
> > -quiet_cmd_hzfile = HZFILE $@
> > - cmd_hzfile = echo "hz=$(CONFIG_HZ)" > $@
> > -
> > -targets += hz.bc
> > -$(obj)/hz.bc: $(objtree)/include/config/hz.h FORCE
> > - $(call if_changed,hzfile)
> > -
> > -quiet_cmd_bc = BC $@
> > - cmd_bc = bc -q $(filter-out FORCE,$^) > $@
> > -
> > -targets += timeconst.h
> > -$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
> > - $(call if_changed,bc)
> > -
> > +$(obj)/time.o: $(objtree)/include/config/
>
> It looks like it has to recompile because of this dependency. Can't we
> just remove this line?
>
yup - thats ok to drop as well - sorry that should have gone out
after build testing.

thx!
hofrat