diff options
| author | Jeff Davis <jdavis@postgresql.org> | 2020-06-07 09:14:24 -0700 |
|---|---|---|
| committer | Jeff Davis <jdavis@postgresql.org> | 2020-06-07 09:25:55 -0700 |
| commit | 1fbb6c93df30801f83c6804ab7befde3cdefe677 (patch) | |
| tree | 8c136b2642614ef2e626cccdd11925293416ac35 | |
| parent | aa7927698acb813283d21aa6a47a67cd3c5a8b0c (diff) | |
| download | postgresql-1fbb6c93df30801f83c6804ab7befde3cdefe677.tar.gz postgresql-1fbb6c93df30801f83c6804ab7befde3cdefe677.zip | |
Fix platform-specific performance regression in logtape.c.
Commit 24d85952 made a change that indirectly caused a performance
regression by triggering a change in the way GCC optimizes memcpy() on
some platforms.
The behavior seemed to contradict a GCC document, so I filed a report:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95556
This patch implements a narrow workaround which eliminates the
regression I observed. The workaround is benign enough that it seems
unlikely to cause a different regression on another platform.
Discussion: https://postgr.es/m/99b2eab335c1592c925d8143979c8e9e81e1575f.camel@j-davis.com
| -rw-r--r-- | src/backend/utils/sort/logtape.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/backend/utils/sort/logtape.c b/src/backend/utils/sort/logtape.c index 666a7c0e81c..4984f8ce50a 100644 --- a/src/backend/utils/sort/logtape.c +++ b/src/backend/utils/sort/logtape.c @@ -782,7 +782,7 @@ LogicalTapeWrite(LogicalTapeSet *lts, int tapenum, Assert(lt->buffer_size == BLCKSZ); while (size > 0) { - if (lt->pos >= TapeBlockPayloadSize) + if (lt->pos >= (int) TapeBlockPayloadSize) { /* Buffer full, dump it out */ long nextBlockNumber; |