On Mon, Jan 6, 2014 at 3:57 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> On Mon, Jan 6, 2014 at 3:32 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: >>> I agree it'd be nicer if we had some better way than mere manual >>> inspection to enforce proper use of spinlocks; but this change doesn't >>> seem to me to move the ball downfield by any meaningful distance. > >> Well, my thought was mainly that, while it may be a bad idea to take >> another spinlock while holding a spinlock under any circumstances, >> somebody might do it and it might appear to work just fine. The most >> likely sequences seems to me to be something like SpinLockAcquire(...) >> followed by LWLockConditionalAcquire(), thinking that things are OK >> because the lock acquisition is conditional - but in fact the >> conditional acquire still takes the spinlock unconditionally. > > The point I'm making is that no such code should get past review, > whether it's got an obvious performance problem or not.
Sure, I agree, but we all make mistakes. It's just a judgement call as to how likely you think it is that someone might make this particular mistake, a topic upon which opinions may vary. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
