Re: [RFC] fs: Avoid to use lockdep information if it's turned off

David Sterba
2020-11-13T17:21:19Z

On Thu, Nov 12, 2020 at 11:22:12AM +0800, Boqun Feng wrote:
> For the "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" warning, do you see
> that every time when you run xfstests and don't see other lockdep
> splats? If so, that means we reach the limitation of number of lockdep
> hlock chains, and we should fix that.

It's not every time and depends on the release, eg. I found no reports
in a sample log for 5.7..5.9, while there are many for 5.2..5.6 and
5.10, every 2nd or 3rd run.

[ 0.185150] ... MAX_LOCKDEP_SUBCLASSES: 8
[ 0.186202] ... MAX_LOCK_DEPTH: 48
[ 0.187286] ... MAX_LOCKDEP_KEYS: 8192
[ 0.188404] ... CLASSHASH_SIZE: 4096
[ 0.189519] ... MAX_LOCKDEP_ENTRIES: 32768
[ 0.190672] ... MAX_LOCKDEP_CHAINS: 65536
[ 0.191814] ... CHAINHASH_SIZE: 32768