pgsql: Avoid need for valgrind suppressions for pg_atomic_init_u64 on s - Mailing list pgsql-committers

From Andres Freund
Subject pgsql: Avoid need for valgrind suppressions for pg_atomic_init_u64 on s
Date
Msg-id E1jiUsi-0004C5-8P@gemulon.postgresql.org
Whole thread Raw
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Avoid need for valgrind suppressions for pg_atomic_init_u64 on some platforms.

Previously we used pg_atomic_write_64_impl inside
pg_atomic_init_u64. That works correctly, but on platforms without
64bit single copy atomicity it could trigger spurious valgrind errors
about uninitialized memory, because we use compare_and_swap for atomic
writes on such platforms.

I previously suppressed one instance of this problem (6c878edc1df),
but as Tom reports that wasn't enough. As the atomic variable cannot
yet be concurrently accessible during initialization, it seems better
to have pg_atomic_init_64_impl set the value directly.

Change pg_atomic_init_u32_impl for symmetry.

Reported-By: Tom Lane
Author: Andres Freund
Discussion: https://postgr.es/m/1714601.1591503815@sss.pgh.pa.us
Backpatch: 9.5-

Branch
------
REL_10_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/20fd90febc2c2429a0340d476cccc6922f581305

Modified Files
--------------
src/include/port/atomics/generic.h |  4 ++--
src/tools/valgrind.supp            | 14 --------------
2 files changed, 2 insertions(+), 16 deletions(-)


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