From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Mon, 28 Jan 2019 09:23:16 +0100 Subject: [Buildroot] [PATCH 1/1] fs/common.mk: enable multithreaded xz compression In-Reply-To: <87a7jln4bt.fsf@dell.be.48ers.dk> References: <1548036475-25449-1-git-send-email-james.hilliard1@gmail.com> <871s55ykoj.fsf@dell.be.48ers.dk> <20190126150622.23c7375e@windsurf> <87a7jln4bt.fsf@dell.be.48ers.dk> Message-ID: <20190128092316.66c4eaa0@windsurf> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On Sun, 27 Jan 2019 23:06:14 +0100 Peter Korsgaard wrote: > > Does it matter than the output of -T 0 and -T 1 are identical ? > > It would cause an extra change in output between buildroot versions > using -T 0 and ones using -T 1 - But OK, probably that isn't really > important given all the other changes. Well, BR2_REPRODUCIBLE is definitely not about guaranteeing identical output between Buildroot versions. How could this even work, since we are bumping the version of dozens/hundreds of packages ? BR2_REPRODUCIBLE is about given a fixed Buildroot version and configuration, be able to generate a binary-identical result. > > What matters for BR2_REPRODUCIBLE=y is if the same input, with -T 0, > > always provide the exact identical output. > > With the new patch that only enables -T 1 for !reproducible builds, > that is correct. I thought -T 0 was the problematic thing as it enabled automatic parallelization, while -T 1 explicitly disabled parallelization. Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com