On Thu, Jan 2, 2025, at 9:00 AM, Dmitry Konishchev wrote: > According to > https://patchew.org/linux/20230908235115.2943486-1-nphamcs@xxxxxxxxx/, > there is no reason to use zbud/z3fold zpool allocators now comparing to > zsmalloc, which has became the default in upstream kernel. > > But Fedora still uses zbud: > > $ grep CONFIG_ZSWAP_ZPOOL /boot/config-6.12.6-200.fc41.x86_64 > CONFIG_ZSWAP_ZPOOL_DEFAULT_ZBUD=y > # CONFIG_ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED is not set > # CONFIG_ZSWAP_ZPOOL_DEFAULT_ZSMALLOC is not set > CONFIG_ZSWAP_ZPOOL_DEFAULT="zbud" > > Should this default be changed? I agree it should be changed. Booting with kernel parameters: zswap.enabled=1 zswap.max_pool_percent=15 zswap.zpool=zsmalloc zswap.compressor=zstd results in: Jan 07 11:46:32 fovo.local kernel: zswap: loaded using pool zstd/zsmalloc And it is working fine. Yes, zsmalloc allocator is dynamic so we'll get better than the 2:1 benefit from lzo/zbud which is the current default for Fedora kernels when booting with: zswap.enabled=1 zswap.max_pool_percent=15 Further, zsmalloc is the allocator used by zram, and we're using zram for swap by default for a number of years now. As for which compression algorithm to use, I think either zstd or lz4 are better options compared to lzo so that too should be changed at the same time. We're already using zstd extensively in Fedora, for RPMs, and Btrfs compression. I think it's uncontroversial to use it here too. But I'm open to the idea of using lz4. -- Chris Murphy -- _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-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/devel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
