diff options
author | Patrick Steinhardt <ps@pks.im> | 2024-01-03 09:22:39 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2024-01-03 20:54:21 +0300 |
commit | 5473aca3767b00eab502b34a37b595de099980ae (patch) | |
tree | cf795cc7a1805ccab93c51e1b57e876045a9db2c | |
parent | b31e3cc620f926273af9346fbda4ff507f60682e (diff) |
reftable/merged: really reuse buffers to compute record keys
In 829231dc20 (reftable/merged: reuse buffer to compute record keys,
2023-12-11), we have refactored the merged iterator to reuse a pair of
long-living strbufs by relying on the fact that `reftable_record_key()`
tries to reuse already allocated strbufs by calling `strbuf_reset()`,
which should give us significantly fewer reallocations compared to the
old code that used on-stack strbufs that are allocated for each and
every iteration. Unfortunately, we called `strbuf_release()` on these
long-living strbufs that we meant to reuse on each iteration, defeating
the optimization.
Fix this performance issue by not releasing those buffers on iteration
anymore, where we instead rely on `merged_iter_close()` to release the
buffers for us.
Using `git show-ref --quiet` in a repository with ~350k refs this leads
to a significant drop in allocations. Before:
HEAP SUMMARY:
in use at exit: 21,163 bytes in 193 blocks
total heap usage: 1,410,148 allocs, 1,409,955 frees, 61,976,068 bytes allocated
After:
HEAP SUMMARY:
in use at exit: 21,163 bytes in 193 blocks
total heap usage: 708,058 allocs, 707,865 frees, 36,783,255 bytes allocated
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r-- | reftable/merged.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/reftable/merged.c b/reftable/merged.c index 556bb5c556..a28bb99aaf 100644 --- a/reftable/merged.c +++ b/reftable/merged.c @@ -128,8 +128,6 @@ static int merged_iter_next_entry(struct merged_iter *mi, done: reftable_record_release(&entry.rec); - strbuf_release(&mi->entry_key); - strbuf_release(&mi->key); return err; } |