Re: stuck spin lock with many concurrent users - Mailing list pgsql-hackers

From Tom Lane
Subject Re: stuck spin lock with many concurrent users
Date
Msg-id 2728.994340823@sss.pgh.pa.us
Whole thread Raw
In response to Re: stuck spin lock with many concurrent users  (Tatsuo Ishii <t-ishii@sra.co.jp>)
List pgsql-hackers
Tatsuo Ishii <t-ishii@sra.co.jp> writes:
> If so, what about increase the dead lock timer proportional to the
> length of the waiting holder queue?

I don't think that's a good idea; it's not solving the problem, only
reducing performance, and in a fairly arbitrary way at that.  (The
length of the particular wait queue you happen to be on is no measure
of the total number of processes waiting for locks.)

The real problem is in the spinlock implementation --- deadlock checking
is only one place where lots of processes might gang up on the same
spinlock.  The bufmgr lock is another one.
        regards, tom lane


pgsql-hackers by date:

Previous
From: Zeugswetter Andreas SB
Date:
Subject: AW: Re: Backup and Recovery
Next
From: Tom Lane
Date:
Subject: Re: Re: Buffer access rules, and a probable bug