On 11/6/24 22:22, Mikulas Patocka wrote:
>
>
> On Wed, 6 Nov 2024, Vlastimil Babka wrote:
>
>> On 11/6/24 13:05, Mikulas Patocka wrote:
>> >
>> >
>> > On Wed, 6 Nov 2024, Vlastimil Babka wrote:
>> >
>> >> On 11/6/24 12:19, Mikulas Patocka wrote:
>> >> > Hi
>> >>
>> >> Hi,
>> >>
>> >> > The commit 4c39529663b93165953ecf9b1a9ea817358dcd06 ("slab: Warn on
>> >> > duplicate cache names when DEBUG_VM=y") is causing large number of
>> >> > warnings about "dm_bufio_buffer", "dm_bufio_buffer-%u" (and other) device
>> >> > mapper caches.
>> >>
>> >> Hmm wonder why nobody run into this before. We thought the code that would
>> >> cause the warning would be all fixed before introducing it, but we missed
>> >> some, sorry.
>> >>
>> >> > I'd like to ask - how to properly fix it?
>> >> >
>> >> > We create a "dm_bufio_buffer" or "dm_bufio_buffer-%u" cache with every dm
>> >> > bufio client. It used to work (and the duplicate caches are merged), but
>> >>
>> >> Note the merging can be disabled so then it's really several caches with
>> >> exactly same name in /proc/slabinfo and inability to create their
>> >> sysfs/debugfs directories.
>> >
>> > Would it be sensible to allow merging caches with the same name and same
>> > attributes and only warn if there are caches with the same name and
>> > different attributes?
>>
>> We might consider that.
>
> That would be good - so that users don't have to write their own slab
> cache merge logic.
So Pedro, wanna do that? Or Hyeonggon maybe? :)
