Re: Atomics for heap_parallelscan_nextpage()
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>,
David Rowley <david.rowley@2ndquadrant.com>,
PostgreSQL-development <pgsql-hackers@postgresql.org>,
Amit Khandekar <amitdkhan.pg@gmail.com>,
Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>,
Robert Haas <robertmhaas@gmail.com>
Date: 2017-08-16T22:31:04Z
Lists: pgsql-hackers
Andres Freund <andres@anarazel.de> writes: > On August 16, 2017 3:09:27 PM PDT, Tom Lane <tgl@sss.pgh.pa.us> wrote: >> I wonder whether it's sensible to have --enable-cassert have the effect >> of filling memory allocated by ShmemAlloc or the DSA code with junk (as >> palloc does) instead of leaving it at zeroes. It's not modeling the >> same kind of effect, since we have no shmem-freeing primitives, but >> it might be useful for this sort of thing. > We kind of do - crash restarts... So yes, that's probably a good idea. Crash restart releases the shmem segment and acquires a new one, doesn't it? Or am I misremembering? I thought that it did do so, if only to make darn sure that no old processes remain connected to shmem. regards, tom lane
Commits
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Fix pg_atomic_u64 initialization.
- dcd052c8d20c 11.0 landed
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Fix shm_toc.c to always return buffer-aligned memory.
- ac883ac453e9 11.0 landed
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Use atomic ops to hand out pages to scan in parallel scan.
- 3cda10f41bfe 11.0 landed
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Improve 64bit atomics support.
- e8fdbd58fe56 10.0 cited