On Fri, Oct 02, 2020 at 04:12:46PM +0200, Bohdan Khomutskyi wrote: > Hello Don, > > I filed a new merge request for this suggestion. It is now open at the > following URI: > https://gitlab.com/cki-project/kernel-ark/-/merge_requests/673 Perfect. Thanks! I see Justin already accepted it! Cheers, Don > > Kind regards, > > On 29/09/2020 16:34, Don Zickus wrote: > > On Fri, Sep 18, 2020 at 10:49:09AM +0200, Bohdan Khomutskyi wrote: > > > Hello, > > > > > > While working on the change proposal > > > https://fedoraproject.org/wiki/Changes/OptimizeSquashFS > > > > > > I discovered that several kernel configuration options are set sub-optimally > > > in Fedora. In RHEL 8, the optimal configuration is used. > > > If we set those options to match RHEL 8, a performance improvement could be > > > achieved while reading the SquashFS filesystem. > > > > > > Below you can see an excerpt from the configuration help: > > Would you be willing to submit a merge request with these changes for > > Fedora? Then we can have a discussion and review. > > > > Cheers, > > Don > > > > > Set in RHEL 8: > > > > > > SQUASHFS_FILE_DIRECT > > >     Directly decompress file data into the page cache. > > >     Doing so can significantly improve performance because > > >     it eliminates a memcpy and it also removes the lock contention > > >     on the single buffer. > > > > > > SQUASHFS_DECOMP_MULTI_PERCPU > > >     By default Squashfs uses a single decompressor but it gives > > >     poor performance on parallel I/O workloads when using multiple CPU > > >     machines due to waiting on decompressor availability. > > > > > >     This decompressor implementation uses a maximum of one > > >     decompressor per core. It uses percpu variables to ensure > > >     decompression is load-balanced across the cores. > > > > > > Set in Fedora: > > > SQUASHFS_DECOMP_SINGLE > > >     Traditionally Squashfs has used single-threaded decompression. > > >     Only one block (data or metadata) can be decompressed at any > > >     one time. This limits CPU and memory usage to a minimum. > > > > > > SQUASHFS_FILE_CACHE > > >     Decompress file data into an intermediate buffer and then > > >     memcopy it into the page cache. > > > > > > The SquashFS filesystem is used on installation medium. So making the change > > > I propose should improve the user experience during installation. It should > > > also improve the user experience while booting from Fedora Live image. > > > > > > Kind regards, > > > > > > -- > > > Bohdan Khomutskyi > > > Software engineer > > > Red Hat > > > _______________________________________________ > > > kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx > > > To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx > > -- > Bohdan Khomutskyi > Software engineer > Red Hat > _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx
