Messages in this thread | | | Date | Tue, 9 May 2023 17:37:55 -0400 | Subject | Re: [PATCH 03/32] locking/lockdep: lockdep_set_no_check_recursion() | From | Waiman Long <> |
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On 5/9/23 16:35, Kent Overstreet wrote: > On Tue, May 09, 2023 at 04:27:46PM -0400, Waiman Long wrote: >> On 5/9/23 16:18, Kent Overstreet wrote: >>> On Tue, May 09, 2023 at 09:31:47PM +0200, Peter Zijlstra wrote: >>>> On Tue, May 09, 2023 at 12:56:28PM -0400, Kent Overstreet wrote: >>>>> This adds a method to tell lockdep not to check lock ordering within a >>>>> lock class - but to still check lock ordering w.r.t. other lock types. >>>>> >>>>> This is for bcachefs, where for btree node locks we have our own >>>>> deadlock avoidance strategy w.r.t. other btree node locks (cycle >>>>> detection), but we still want lockdep to check lock ordering w.r.t. >>>>> other lock types. >>>>> >>>> ISTR you had a much nicer version of this where you gave a custom order >>>> function -- what happend to that? >>> Actually, I spoke too soon; this patch and the other series with the >>> comparison function solve different problems. >>> >>> For bcachefs btree node locks, we don't have a defined lock ordering at >>> all - we do full runtime cycle detection, so we don't want lockdep >>> checking for self deadlock because we're handling that but we _do_ want >>> lockdep checking lock ordering of btree node locks w.r.t. other locks in >>> the system. >> Maybe you can use lock_set_novalidate_class() instead. > No, we want that to go away, this is the replacement.
OK, you can mention that in the commit log then.
Cheers, Longman
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