On 24 June 2016 at 03:59, Dave Airlie <airl...@gmail.com> wrote: > On 23 June 2016 at 23:25, Emil Velikov <emil.l.veli...@gmail.com> wrote: >> On 23 June 2016 at 03:49, Michel Dänzer <mic...@daenzer.net> wrote: >>> On 22.06.2016 21:04, Emil Velikov wrote: >>>> From: Emil Velikov <emil.veli...@collabora.com> >>>> >>>> Do not rely on the git sha1: >>>> - its current truncated form makes it less unique >>>> - it does not attribute for local (Vulkand or otherwise) changes >>>> >>>> Use a timestamp produced at the time of build. It's perfectly unique, >>>> unless someone explicitly thinkers with their system clock. Even then >>>> chances of producing the exact same one are very small, if not zero. >>>> >>>> Cc: Jason Ekstrand <ja...@jlekstrand.net> >>>> Cc: mesa-sta...@lists.freedesktop.org >>>> Signed-off-by: Emil Velikov <emil.veli...@collabora.com> >>>> --- >>>> Current approach uses seconds since Epoch, but if people prefer we >>>> can use nano seconds, combination of the two and/or other. >>>> --- >>>> src/intel/vulkan/.gitignore | 2 ++ >>>> src/intel/vulkan/Makefile.am | 15 ++++++++++++++- >>>> src/intel/vulkan/anv_device.c | 4 ++-- >>>> 3 files changed, 18 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/src/intel/vulkan/.gitignore b/src/intel/vulkan/.gitignore >>>> index a496146..7ef6a48 100644 >>>> --- a/src/intel/vulkan/.gitignore >>>> +++ b/src/intel/vulkan/.gitignore >>>> @@ -2,3 +2,5 @@ >>>> /anv_entrypoints.c >>>> /anv_entrypoints.h >>>> /dev_icd.json >>>> +/anv_timestamp.h.tmp >>>> +/anv_timestamp.h >>>> diff --git a/src/intel/vulkan/Makefile.am b/src/intel/vulkan/Makefile.am >>>> index 4d9ff90..8332ae5 100644 >>>> --- a/src/intel/vulkan/Makefile.am >>>> +++ b/src/intel/vulkan/Makefile.am >>>> @@ -131,7 +131,20 @@ anv_entrypoints.c : anv_entrypoints_gen.py >>>> $(vulkan_include_HEADERS) >>>> $(AM_V_GEN) cat $(vulkan_include_HEADERS) |\ >>>> $(PYTHON2) $(srcdir)/anv_entrypoints_gen.py code > $@ >>>> >>>> -BUILT_SOURCES = $(VULKAN_GENERATED_FILES) >>>> + >>>> +.PHONY: anv_timestamp.h.tmp >>>> +anv_timestamp.h.tmp: >>>> + $(AM_V_GEN) echo "#define ANV_TIMESTAMP `date +%s`" > $@ >>> >>> This conflicts with efforts to make builds reproducible, see e.g. >>> https://wiki.debian.org/ReproducibleBuilds . One technique used by such >>> efforts is to replace any timestamps with all 0s. >>> >> Thanks to letting me know before things got swapped with 0s. Is there >> a way to contact/check how other projects have handled/resolved this ? >> The page linked looks like a policy/guidelines one and I'm struggling >> to see any examples of how things were resolved for project X or Y :-\ >> >>> >>> Would it be possible to generate a hash over all source files listed in >>> any Makefile.sources, or something like that? >>> >> If you want to pursue that task please do. >> >> A couple of humble requests a) can you get some very rough measurement >> how long all the hashing takes, b) please try to avoid adding extra >> external dependencies (not sure how many people will like that). >> > > I think you should be taking that as a NAK for this approach. > Hmm possibly. I would really appreciate if people say so from the beginning.
> If one of the reasons for not using the git_sha1 is we can't detect > patches from distros, and one distro is knowingly going to have to > patch the approach out, then the approach isn't really suitable. > There are multiple reasons for reworking the git_sha1.h dependency, here's a few: - multiple reports that git_sha1.h broke my workflow', with people resisting the suggested one line fix - some people ignore the suggestion and place something else "which should be enough" - others outright revert the patch(es) that mandate git_sha1.h - provides uniqueness, even if one patches the sources. > I'm also not sure but does running make install on the same tree twice > re-generate this file? or did we take that into a/c? > I did consider that - thus my 'use a define' suggestions above. Guess I should have explicitly mentioned that it will be added _only_ to the file(s) that need it. Thus the whole anv won't get rebuilt, as per Jason's concern. To sum it up: the goal is to minimise complains/reverts/other from builders while saving Jason, you, others time debugging, when old cache(s) are used. -Emil _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
