Ahh, thank you both for the clarification. On 11/08/2018 01:35 AM, Felix Fietkau wrote: > On 2018-11-08 02:20, Daniel Santos wrote: >> On 11/07/2018 01:52 PM, Felix Fietkau wrote: >>> On 2018-11-05 00:19, Daniel Santos wrote: >>>> This was disabled by commit dcd0e4a6727611f03eb3d3a75f073235f5f1229c due >>>> to a threading bug back in 2009. The specifics of the bug are not given >>>> in the commit message and squashfs-tools has had several updates to it's >>>> parallelism since this time. There are currently no open issues related >>>> to parallelism in their issue tracker: >>>> https://github.com/plougher/squashfs-tools/issues >>>> >>>> It now "works for me" with 16 threads, and while this is a terrible test >>>> for a race condition I still propose we remove this work-around >>>> unless and until we have specific knowledge of a current bug. >>>> >>>> Signed-off-by: Daniel Santos <[email protected]> >>> Are the images still reproducible after that change? >>> If I remember correctly, threading would break that. >> Hello. I'm not sure what you mean by the images being reproducible. >> I've been building with TARGET_ROOTFS_SQUASHFS=y and >> TARGET_ROOTFS_SQUASHFS=256 for a few weeks now without any problem. I'm >> presuming they've fixed it, but I didn't see specific mention of this >> bug in their github issue tracker. They may have discussed it elsewhere >> prior to porting to github. > Reproducible as in https://reproducible-builds.org/ > You're supposed to be able to generate the binary-identical rootfs image > on different machines, as long as you're using the same version and the > same configuration. > >From my understanding, using multiple threads for the squashfs build can > make the order in which data appears in the filesystem image > non-deterministic. > > - Felix
I see. I have definitely not tested that. I would assume they could vary from one build to another based upon my understanding of how multi-threaded compression is done in general. How about a patch that allows multi-threaded compression via a .config option? Thanks, Daniel _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
