From: Derrick Stolee <derrickstolee@github.com>
To: "Jeff King" <peff@peff.net>, 程洋 <chengyang@xiaomi.com>
Cc: "git@vger.kernel.org" <git@vger.kernel.org>,
何浩 <hehao@xiaomi.com>, "Xin7 Ma 马鑫" <maxin7@xiaomi.com>,
石奉兵 <shifengbing@xiaomi.com>, 凡军辉 <fanjunhui@xiaomi.com>,
王汉基 <wanghanji@xiaomi.com>
Subject: Re: [PATCH 0/3] speeding up on-demand fetch for blobs in partial clone
Date: Wed, 7 Sep 2022 10:48:04 -0400 [thread overview]
Message-ID: <fc4ce953-1a3b-8d94-d602-ad3e195f08c9@github.com> (raw)
In-Reply-To: <YxfQi4qg8uJHs7Gp@coredump.intra.peff.net>
On 9/6/2022 6:58 PM, Jeff King wrote:
> On Tue, Sep 06, 2022 at 02:38:41PM -0400, Jeff King wrote:
>
>> On Mon, Sep 05, 2022 at 11:17:21AM +0000, 程洋 wrote:
>>
>>> Sorry, I told you the wrong branch. It should be "android-t-preview-1"
>>> git clone --filter=blob:none --no-local -b android-t-preview-1 grade-plugin
>>>
>>> Can you try this one?
>>
>> Yes, I see more slow-down there. There are many more blobs there, but I
>> don't think it's really the number of them, but their sizes.
>>
>> The problem is that both upload-pack and pack-objects are keen to call
>> parse_object() on their inputs. For commits, etc, that is usually
>> sensible; we have to parse the object to see what it points to. But for
>> blobs, the only thing we do is inflate a ton of bytes in order to check
>> the sha1. That's not really productive here; if there is a bit
>> corruption, the client will notice it on the receiving side.
Thanks for finding this very subtle issue!
> So here's a cleaned-up series which makes this a lot faster.
>
> The special sauce is in patch 2, along with timings. The first one is
> just preparing, and the final one is a small cleanup it enables.
I carefully read these patches as well as applied them on my machine
and did some extra digging and performance tests to understand the
change.
LGTM.
Thanks,
-Stolee
prev parent reply other threads:[~2022-09-07 14:49 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-11 8:09 Partial-clone cause big performance impact on server 程洋
2022-08-11 17:22 ` Jonathan Tan
2022-08-13 7:55 ` 回复: [External Mail]Re: " 程洋
2022-08-13 11:41 ` 程洋
2022-08-15 5:16 ` ZheNing Hu
2022-08-15 13:15 ` 程洋
2022-08-12 12:21 ` Derrick Stolee
2022-08-14 6:48 ` Jeff King
2022-08-15 13:18 ` Derrick Stolee
2022-08-15 14:50 ` [External Mail]Re: " 程洋
2022-08-17 10:22 ` 程洋
2022-08-17 13:41 ` Derrick Stolee
2022-08-18 5:49 ` Jeff King
2022-09-01 6:53 ` 程洋
2022-09-01 16:19 ` Jeff King
2022-09-05 11:17 ` 程洋
2022-09-06 18:38 ` Jeff King
2022-09-06 22:58 ` [PATCH 0/3] speeding up on-demand fetch for blobs in partial clone Jeff King
2022-09-06 23:01 ` [PATCH 1/3] parse_object(): allow skipping hash check Jeff King
2022-09-07 14:15 ` Derrick Stolee
2022-09-07 20:44 ` Jeff King
2022-09-06 23:05 ` [PATCH 2/3] upload-pack: skip parse-object re-hashing of "want" objects Jeff King
2022-09-07 14:36 ` Derrick Stolee
2022-09-07 14:45 ` Derrick Stolee
2022-09-07 20:50 ` Jeff King
2022-09-07 19:26 ` Junio C Hamano
2022-09-07 20:36 ` Jeff King
2022-09-07 20:48 ` [BUG] t1800: Fails for error text comparison rsbecker
2022-09-07 21:55 ` Junio C Hamano
2022-09-07 22:23 ` rsbecker
2022-09-07 21:02 ` [PATCH 2/3] upload-pack: skip parse-object re-hashing of "want" objects Jeff King
2022-09-07 22:07 ` Junio C Hamano
2022-09-08 5:04 ` Jeff King
2022-09-08 16:41 ` Junio C Hamano
2022-09-06 23:06 ` [PATCH 3/3] parse_object(): check commit-graph when skip_hash set Jeff King
2022-09-07 14:46 ` Derrick Stolee
2022-09-07 19:31 ` Junio C Hamano
2022-09-08 10:39 ` [External Mail]Re: " 程洋
2022-09-08 18:42 ` Jeff King
2022-09-07 14:48 ` Derrick Stolee [this message]
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