On Tue, Mar 6, 2012 at 2:17 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> writes: >> On 21.02.2012 13:19, Fujii Masao wrote: >>> In some places, the spinlock "insertpos_lck" is taken while another >>> spinlock "info_lck" is being held. Is this OK? What if unfortunately >>> inner spinlock takes long to be taken? > >> Hmm, that's only done at a checkpoint (and a restartpoint), so I doubt >> that's a big issue in practice. We had the same pattern before the >> patch, just with WALInsertLock instead of insertpos_lck. Holding a >> spinlock longer is much worse than holding a lwlock longer, but >> nevertheless I don't think that's a problem. > > No, that's NOT okay. A spinlock is only supposed to be held across a > short straight-line sequence of instructions.
This also strikes me that the usage of the spinlock insertpos_lck might not be OK in ReserveXLogInsertLocation() because a few dozen instructions can be performed while holding the spinlock.... Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers