[Ocfs2-devel] questions of AST and BAST (was Re: dlm stress test hangs OCFS2)

[Coly Li]

Sunil Mushran Wrote:
> 
> BAST:
> [368.807757] (2572,dlm_astd,0):ocfs2_blocking_ast:1025 BAST fired for
> lockres M0000000000000000085e0200000000, blocking 5, level 3 type Meta
> [368.807767] (2571,ocfs2dc,0):ocfs2_process_blocked_lock:3839 lockres
> M0000000000000000085e0200000000 blocked.
> [368.807774] (2571,ocfs2dc,0):ocfs2_prepare_downconvert:3232 lock
> M0000000000000000085e0200000000, new_level = 0, l_blocking = 5
> [368.807779] (2571,ocfs2dc,0):ocfs2_downconvert_lock:3252 lock
> M0000000000000000085e0200000000, level 3 => 0
> [368.807799] (2571,ocfs2dc,0):ocfs2_process_blocked_lock:3863 lockres
> M0000000000000000085e0200000000, requeue = no.
> 
> Downconvert AST:
> [368.807806] (2572,dlm_astd,0):ocfs2_locking_ast:1069 lock
> M0000000000000000085e0200000000, action 3, unlock 0
> 
> Upconvert AST:
> [369.007930] (2572,dlm_astd,0):ocfs2_locking_ast:1069 lock
> M0000000000000000085e0200000000, action 2, unlock 0
> 
> BAST:
> [369.007946] (2572,dlm_astd,0):ocfs2_blocking_ast:1025 BAST fired for
> lockres M0000000000000000085e0200000000, blocking 5, level 3 type Meta
> [369.007956] (2571,ocfs2dc,0):ocfs2_process_blocked_lock:3839 lockres
> M0000000000000000085e0200000000 blocked.
> [369.007962] (2571,ocfs2dc,0):ocfs2_prepare_downconvert:3232 lock
> M0000000000000000085e0200000000, new_level = 0, l_blocking = 5
> [369.007967] (2571,ocfs2dc,0):ocfs2_downconvert_lock:3252 lock
> M0000000000000000085e0200000000, level 3 => 0
> [369.007987] (2571,ocfs2dc,0):ocfs2_process_blocked_lock:3863 lockres
> M0000000000000000085e0200000000, requeue = no.
> 
> Downconvert AST:
> [369.007994] (2572,dlm_astd,0):ocfs2_locking_ast:1069 lock
> M0000000000000000085e0200000000, action 3, unlock 0
> 
> Upconvert AST:
> [369.208048] (2572,dlm_astd,0):ocfs2_locking_ast:1069 lock
> M0000000000000000085e0200000000, action 2, unlock 0

Hi Sunil,

It is still not very clear to me, for the conception of AST and BAST in ocfs2.

I guess in ocfs2, when downconvert or upconvert gets done, there will be a AST
popped. But it's not clear to me in which conditions the AST will happen, and
when a BAST will happen.

Can I get any hint ?  :-)

Thanks
-- 
Coly Li
SuSE Labs