Re: SlabCheck leaks memory into TopMemoryContext

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Andres Freund <andres@anarazel.de>, Tomas Vondra <tv@fuzzy.cz>, pgsql-hackers@postgresql.org
Date: 2020-01-16T16:43:34Z
Lists: pgsql-hackers
Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> The attached fix should do the trick - it pre-allocates the space when
> creating the context. There is a bit of complexity because we want to
> allocate the space as part of the context header, but nothin too bad. We
> might optimize it a bit by using a regular bitmap (instead of just an
> array of bools), but I haven't done that.

Hmm ... so if this is an array of bools, why isn't it declared bool*
rather than char* ?  (Pre-existing ugliness, sure, but we might as
well fix it while we're here.  Especially since you used sizeof(bool)
in the space calculation.)

I agree that maxaligning the start point of the array is pointless.

I'd write "free chunks in a block" not "free chunks on a block",
the latter seems rather shaky English.  But that's getting picky.

LGTM otherwise.

			regards, tom lane



Commits

  1. Allocate freechunks bitmap as part of SlabContext