Hi Li, all, > Hi Petr, All, > On Sat, Aug 20, 2022 at 3:28 AM Petr Vorel <pvorel@xxxxxxx> wrote: > > Hi all, > > > Hi Cyril, > > > On Thu, Aug 18, 2022 at 1:28 PM Cyril Hrubis <chrubis@xxxxxxx> wrote: > > > > > > I'm starting to wonder if we should start tracking minimal FS size > > per > > > > > > filesystem since btrfs and xfs will likely to continue to grow and > > with > > > > > > that we will end up disabling the whole fs related testing on > > embedded > > > > > > boards with a little disk space. If we tracked that per filesystem > > we > > > > > > would be able to skip a subset of filesystems when there is not > > enough > > > > > > space. The downside is obviously that we would have to add a bit > > more > > > > > > complexity to the test library. > > > > > Maybe I could for start rewrite v2 (I've sent it without Cc kernel > > devs now it's > > > > > mainly LTP internal thing) as it just to have 300 MB for XFS and 256 > > MB for the > > > > > rest. That would require to specify filesystem when acquiring device > > (NULL would > > > > > be for the default filesystem), that's would be worth if embedded > > folks counter > > > > > each MB. It'd be nice to hear from them. > > > > The 256MB limit was set previously due to btrfs, I bet that we can > > > > create smaller images for ext filesytems for example. > > Thanks for input, Geert! > > > Yeah, we used to have ext2 root file systems that fit on 1440 KiB > > floppies. > > These nice times when everything simple hadn't been solved yet ... :). > > > IIRC, ext3 does have a minimum size of 32 MiB or so. > > Interesting, I was able to create smaller. > > I did some testing minimal size (verified on chdir01 test): > > XFS: 300 MB, btrfs: 109 MB, ntfs: 2 MB, ext3: 2 MB, ext[24]: 1 MB, vfat: 1 > > MB, exfat: 1 MB. > > I guess using XFS: 300 MB, btrfs: 109 MB and 16 MB for the rest could be > > enough. > I think so, tracking minimal FS size per FS is a practical idea. > But one thing we have to be aware of is that there may be different > minimal sizes for each FS version. > (so we'd better choose the maximum of minimal sizes). > 16MB for general FS should be fine, I will help to test that if someone > works out the patch. So should we combine both: minimal FS size and those XFS variables which would allow to use lower size for XFS? I wonder which which size would be relevant, it might be safer to use 64 MB: https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/tree/mkfs/xfs_mkfs.c /* * Realistically, the log should never be smaller than 64MB. Studies by the * kernel maintainer in early 2022 have shown a dramatic reduction in long tail * latency of the xlog grant head waitqueue when running a heavy metadata * update workload when the log size is at least 64MB. */ Because there is really not a big difference between 256MB and 300MB. Kind regards, Petr > > But that would require to run all tests to see how many tests actually use > > bigger data. > Absolutely YES!
