From: Matheus Tavares <matheus.bernardino@usp.br>
To: git@vger.kernel.org
Cc: "Christian Couder" <christian.couder@gmail.com>,
"Olga Telezhnaya" <olyatelezhnaya@gmail.com>,
"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
Subject: [GSoC][PATCH 0/4] grep: re-enable threads when cached, w/ parallel inflation
Date: Sat, 10 Aug 2019 17:27:26 -0300 [thread overview]
Message-ID: <cover.1565468806.git.matheus.bernardino@usp.br> (raw)
This series focuses on allowing parallel access to zlib inflation and
using that to perform a faster git-grep in the non-worktree case.
Threads were disabled for this case at 53b8d93 ("grep: disable
threading in non-worktree case", 12-12-2011), due to performance drops.
However, by allowing threads to perform inflation in parallel, we can
regain the speedup. This is a good hotspot for parallelism as some test
cases[1] showed that it can account for up to 48% of execution time.
And besides that, inflation tasks are already independent of each other.
As a result, grepping 'abcd[02]' ("Regex 1") and
'(static|extern) (int|double) \*' ("Regex 2") at chromium's
repository[2], I got (means of 30 executions):
Threads | Regex 1 | Regex 2
---------|------------|-----------
1 | 17.3557s | 20.8410s
2 | 9.7170s | 11.2415s
8 | 6.1723s | 6.9378s
As a reference, just enabling threads in the non-worktree case,
without parallel inflation, I got:
Threads | Regex 1 | Regex 2
---------|------------|-----------
1 | 17.1359s | 20.8306s
2 | 14.5036s | 15.4172s
8 | 13.6304s | 13.8659s
For now, the optimization is not supported when --textconv or
--recurse-submodules are used, but I hope to send another patchset for
that still during GSoC. We may also try to allow even more parallelism,
refining the added 'obj_read_lock'.
[1]: https://matheustavares.gitlab.io/posts/week-6-working-at-zlib-inflation#multithreading-zlib-inflation
[2]: chromium’s repo at commit 03ae96f (“Add filters testing at DSF=2”,
04-06-2019), after a 'git gc' execution.
travis build: https://travis-ci.org/matheustavares/git/builds/570255029
Matheus Tavares (4):
object-store: add lock to read_object_file_extended()
grep: allow locks to be enabled individually
grep: disable grep_read_mutex when possible
grep: re-enable threads in some non-worktree cases
Documentation/git-grep.txt | 12 ++++++++
builtin/grep.c | 22 +++++++++++---
grep.c | 4 +--
grep.h | 8 +++--
object-store.h | 4 +++
packfile.c | 7 +++++
sha1-file.c | 61 ++++++++++++++++++++++++++++++++++----
7 files changed, 105 insertions(+), 13 deletions(-)
--
2.22.0
next reply other threads:[~2019-08-10 20:27 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-10 20:27 Matheus Tavares [this message]
2019-08-10 20:27 ` [GSoC][PATCH 1/4] object-store: add lock to read_object_file_extended() Matheus Tavares
2019-08-10 20:27 ` [GSoC][PATCH 2/4] grep: allow locks to be enabled individually Matheus Tavares
2019-08-10 20:27 ` [GSoC][PATCH 3/4] grep: disable grep_read_mutex when possible Matheus Tavares
2019-08-10 20:27 ` [GSoC][PATCH 4/4] grep: re-enable threads in some non-worktree cases Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 00/11] grep: improve threading and fix race conditions Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 01/11] grep: fix race conditions on userdiff calls Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 02/11] grep: fix race conditions at grep_submodule() Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 03/11] grep: fix racy calls in grep_objects() Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 04/11] replace-object: make replace operations thread-safe Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 05/11] object-store: allow threaded access to object reading Matheus Tavares
2019-11-12 2:54 ` Jonathan Tan
2019-11-13 5:20 ` Jeff King
2019-11-14 5:57 ` Matheus Tavares Bernardino
2019-11-14 6:01 ` Jeff King
2019-11-14 18:15 ` Jonathan Tan
2019-11-15 4:12 ` Jeff King
2019-12-19 22:27 ` Matheus Tavares Bernardino
2020-01-09 22:02 ` Matheus Tavares Bernardino
2020-01-10 19:07 ` Christian Couder
2019-09-30 1:50 ` [PATCH v2 06/11] grep: replace grep_read_mutex by internal obj read lock Matheus Tavares
2019-10-01 19:23 ` [PATCH] squash! " Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 07/11] submodule-config: add skip_if_read option to repo_read_gitmodules() Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 08/11] grep: allow submodule functions to run in parallel Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 09/11] grep: protect packed_git [re-]initialization Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 10/11] grep: re-enable threads in non-worktree case Matheus Tavares
2019-09-30 1:50 ` [PATCH v2 11/11] grep: move driver pre-load out of critical section Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 00/12] grep: improve threading and fix race conditions Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 01/12] grep: fix race conditions on userdiff calls Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 02/12] grep: fix race conditions at grep_submodule() Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 03/12] grep: fix racy calls in grep_objects() Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 04/12] replace-object: make replace operations thread-safe Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 05/12] object-store: allow threaded access to object reading Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 06/12] grep: replace grep_read_mutex by internal obj read lock Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 07/12] submodule-config: add skip_if_read option to repo_read_gitmodules() Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 08/12] grep: allow submodule functions to run in parallel Matheus Tavares
2020-01-29 11:26 ` SZEDER Gábor
2020-01-29 18:49 ` Junio C Hamano
2020-01-29 18:57 ` Junio C Hamano
2020-01-29 20:42 ` Matheus Tavares Bernardino
2020-01-30 13:28 ` Philippe Blain
2020-01-16 2:39 ` [PATCH v3 09/12] grep: protect packed_git [re-]initialization Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 10/12] grep: re-enable threads in non-worktree case Matheus Tavares
2020-01-16 2:39 ` [PATCH v3 11/12] grep: move driver pre-load out of critical section Matheus Tavares
2020-01-16 2:40 ` [PATCH v3 12/12] grep: use no. of cores as the default no. of threads Matheus Tavares
2020-01-16 13:11 ` Victor Leschuk
2020-01-16 14:47 ` [PATCH] " Matheus Tavares
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