From 8da4861b3860c505e39341b4135c21f67569e4d8 Mon Sep 17 00:00:00 2001 From: Kuang-che Wu Date: Tue, 22 Oct 2024 21:04:41 +0800 Subject: subcmds: reduce multiprocessing serialization overhead Follow the same approach as 39ffd9977e to reduce serialization overhead. Below benchmarks are tested with 2.7k projects on my workstation (warm cache). git tracing is disabled for benchmark. (seconds) | v2.48 | v2.48 | this CL | this CL | | -j32 | | -j32 ----------------------------------------------------------- with clean tree state: branches (none) | 5.6 | 5.9 | 1.0 | 0.9 status (clean) | 21.3 | 9.4 | 19.4 | 4.7 diff (none) | 7.6 | 7.2 | 5.7 | 2.2 prune (none) | 5.7 | 6.1 | 1.3 | 1.2 abandon (none) | 19.4 | 18.6 | 0.9 | 0.8 upload (none) | 19.7 | 18.7 | 0.9 | 0.8 forall -c true | 7.5 | 7.6 | 0.6 | 0.6 forall -c "git log -1" | 11.3 | 11.1 | 0.6 | 0.6 with branches: start BRANCH --all | 21.9 | 20.3 | 13.6 | 2.6 checkout BRANCH | 29.1 | 27.8 | 1.1 | 1.0 branches (2) | 28.0 | 28.6 | 1.5 | 1.3 abandon BRANCH | 29.2 | 27.5 | 9.7 | 2.2 Bug: b/371638995 Change-Id: I53989a3d1e43063587b3f52f852b1c2c56b49412 Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/440221 Reviewed-by: Josip Sokcevic Tested-by: Kuang-che Wu Commit-Queue: Kuang-che Wu --- command.py | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'command.py') diff --git a/command.py b/command.py index 2a2ce138..22115ac2 100644 --- a/command.py +++ b/command.py @@ -268,8 +268,10 @@ class Command: cls._parallel_context = None @classmethod - def _SetParallelContext(cls, context): + def _InitParallelWorker(cls, context, initializer): cls._parallel_context = context + if initializer: + initializer() @classmethod def ExecuteInParallel( @@ -281,6 +283,7 @@ class Command: output=None, ordered=False, chunksize=WORKER_BATCH_SIZE, + initializer=None, ): """Helper for managing parallel execution boiler plate. @@ -307,6 +310,7 @@ class Command: ordered: Whether the jobs should be processed in order. chunksize: The number of jobs processed in batch by parallel workers. + initializer: Worker initializer. Returns: The |callback| function's results are returned. @@ -318,8 +322,8 @@ class Command: else: with multiprocessing.Pool( jobs, - initializer=cls._SetParallelContext, - initargs=(cls._parallel_context,), + initializer=cls._InitParallelWorker, + initargs=(cls._parallel_context, initializer), ) as pool: submit = pool.imap if ordered else pool.imap_unordered return callback( -- cgit v1.2.3-54-g00ecf