Jeff Davis <pg...@j-davis.com> writes: > I have a new approach to the patch which is to call a callback at each > block allocation and child contexts inherit the callback from their > parents. The callback could be defined to simply dereference and > increment its argument, which would mean block allocations anywhere in > the hierarchy are incrementing the same variable, avoiding the need to > traverse the hierarchy.
Cute, but it's impossible to believe that a function call isn't going to be *even more* overhead than what you've got now. This could only measure out as a win when the feature is going unused. What about removing the callback per se and just keeping the argument, as it were. That is, a MemoryContext has a field of type "size_t *" that is normally NULL, but if set to non-NULL, then we increment the pointed-to value for pallocs and decrement for pfrees. One thought in either case is that we don't have to touch the API for MemoryContextCreate: rather, the feature can be enabled in a separate call after making the context. regards, tom lane -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers