Hi! Here's a patch set that allows changing the compression level for zstd, currently at mount time only. I've played with it for a month, so despite being a quick hack, it's reasonably well tested. Tested on 4.13 + btrfs-for-4.14 only, though -- I've booted 11th-day-of-merge-window only an hour ago on one machine, no explosions yet.
As a quick hack, it doesn't conserve memory as it should: all workspace allocations assume level 15 and waste space otherwise. Because of an (easily changeable) quirk of compression level encoding, the max is set at 15, but I guess higher levels are pointless for 128KB blocks. Nick and co can tell us more -- for me zstd is mostly a black box so it's you who knows anything about tuning it. There are three patches: * [David Sterba] btrfs: allow to set compression level for zlib Unmodified version of the patch from Jul 24, I'm re-sending it for convenience. * btrfs: allow setting zlib compression level via :9 Some bikeshedding: it looks like Chris Mason also favours zlib:9 over zlib9 as the former is more readable. If you disagree... well, it's up to you to decide anyway. This patch accepts both syntaxes. * btrfs: allow setting zstd level Meow! -- ⢀⣴⠾⠻⢶⣦⠀ I've read an article about how lively happy music boosts ⣾⠁⢰⠒⠀⣿⡁ productivity. You can read it, too, you just need the ⢿⡄⠘⠷⠚⠋⠀ right music while doing so. I recommend Skepticism ⠈⠳⣄⠀⠀⠀⠀ (funeral doom metal). -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
