From: Elijah Newren <newren@gmail.com>
To: Duy Nguyen <pclouds@gmail.com>
Cc: Git Mailing List <git@vger.kernel.org>,
Junio C Hamano <gitster@pobox.com>, Jeff King <peff@peff.net>
Subject: Re: [PATCH] pack-objects: fix performance issues on packing large deltas
Date: Fri, 20 Jul 2018 23:56:30 -0700 [thread overview]
Message-ID: <CABPp-BG_kYw1fWvq0YTTic7AV=nYuoKe9E4QMYVN0R_16xPKaw@mail.gmail.com> (raw)
In-Reply-To: <20180721044711.GA31376@duynguyen.home>
On Fri, Jul 20, 2018 at 9:47 PM, Duy Nguyen <pclouds@gmail.com> wrote:
> On Fri, Jul 20, 2018 at 10:43:25AM -0700, Elijah Newren wrote:
>> Out of curiosity, would it be possible to use the delta_size_ field
>> for deltas that are small enough, and only use an external data
>> structure (perhaps a hash rather than an array) for the few deltas
>> that are large?
>
> We could. And because repack time is still a bit higher in your
> linux.git case. Let's try this. No locking in common case and very
> small locked region when we hit large deltas
Sweet, I'm starting some tests with it...
> -- 8< --
...
> diff --git a/pack-objects.h b/pack-objects.h
> index 9f977ae800..11890e7217 100644
> --- a/pack-objects.h
> +++ b/pack-objects.h
> @@ -15,7 +15,7 @@
...
> @@ -353,37 +354,26 @@ static inline void oe_set_size(struct packing_data *pack,
> static inline unsigned long oe_delta_size(struct packing_data *pack,
> const struct object_entry *e)
> {
> - unsigned long size;
> -
> - packing_data_lock(pack);
> - if (pack->delta_size)
> - size = pack->delta_size[e - pack->objects];
> + if (e->delta_size_valid)
> + return e->delta_size_;
> else
> - size = e->delta_size_;
> - packing_data_unlock(pack);
> - return size;
> + return pack->delta_size[e - pack->objects];
Should this last line be wrapped with packing_data_lock/unlock calls?
(And similarly in oe_set_delta_size when writing to this array?)
> }
>
> -uint32_t *new_delta_size_array(struct packing_data *pdata);
> static inline void oe_set_delta_size(struct packing_data *pack,
> struct object_entry *e,
> unsigned long size)
> {
> - packing_data_lock(pack);
> - if (!pack->delta_size && size < pack->oe_delta_size_limit) {
> - packing_data_unlock(pack);
> + if (size < pack->oe_delta_size_limit) {
> e->delta_size_ = size;
> - return;
> + e->delta_size_valid = 1;
> + } else {
> + packing_data_lock(pack);
> + if (!pack->delta_size)
> + ALLOC_ARRAY(pack->delta_size, pack->nr_alloc);
> + packing_data_unlock(pack);
> + pack->delta_size[e - pack->objects] = size;
> }
> - /*
> - * We have had at least one delta size exceeding OE_DELTA_SIZE_BITS
> - * limit. delta_size_ will not be used anymore. All delta sizes are
> - * now from the delta_size[] array.
> - */
> - if (!pack->delta_size)
> - pack->delta_size = new_delta_size_array(pack);
> - pack->delta_size[e - pack->objects] = size;
> - packing_data_unlock(pack);
> }
>
> #endif
next prev parent reply other threads:[~2018-07-21 6:56 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 22:51 2.18.0 Regression: packing performance and effectiveness Elijah Newren
2018-07-18 22:51 ` [RFC PATCH] fix-v1: revert "pack-objects: shrink delta_size field in struct object_entry" Elijah Newren
2018-07-18 22:51 ` [RFC PATCH] fix-v2: make OE_DELTA_SIZE_BITS a bit bigger Elijah Newren
2018-07-19 5:41 ` 2.18.0 Regression: packing performance and effectiveness Duy Nguyen
2018-07-19 5:49 ` Jeff King
2018-07-19 15:27 ` Elijah Newren
2018-07-19 15:43 ` Duy Nguyen
2018-07-19 5:44 ` Jeff King
2018-07-19 5:57 ` Duy Nguyen
2018-07-19 15:16 ` Duy Nguyen
2018-07-19 16:42 ` Elijah Newren
2018-07-19 17:23 ` Jeff King
2018-07-19 17:31 ` Duy Nguyen
2018-07-19 18:24 ` Duy Nguyen
2018-07-19 19:17 ` Jeff King
2018-07-19 23:11 ` Elijah Newren
2018-07-20 5:28 ` Jeff King
2018-07-20 5:30 ` Jeff King
2018-07-20 5:47 ` Duy Nguyen
2018-07-20 17:21 ` Elijah Newren
2018-07-19 17:04 ` Jeff King
2018-07-19 19:25 ` Junio C Hamano
2018-07-19 19:27 ` Junio C Hamano
2018-07-20 15:39 ` [PATCH] pack-objects: fix performance issues on packing large deltas Nguyễn Thái Ngọc Duy
2018-07-20 17:40 ` Jeff King
2018-07-21 4:23 ` Duy Nguyen
2018-07-23 21:37 ` Jeff King
2018-07-20 17:43 ` Elijah Newren
2018-07-20 23:52 ` Elijah Newren
2018-07-21 4:07 ` Duy Nguyen
2018-07-21 7:08 ` Duy Nguyen
2018-07-21 4:47 ` Duy Nguyen
2018-07-21 6:56 ` Elijah Newren [this message]
2018-07-21 7:14 ` Duy Nguyen
2018-07-22 6:22 ` Elijah Newren
2018-07-22 6:49 ` Duy Nguyen
2018-07-23 12:34 ` Elijah Newren
2018-07-23 15:50 ` Duy Nguyen
2018-07-22 8:04 ` [PATCH v2] " Nguyễn Thái Ngọc Duy
2018-07-23 18:04 ` Junio C Hamano
2018-07-23 18:38 ` Duy Nguyen
2018-07-23 18:49 ` Duy Nguyen
2018-07-23 21:30 ` Jeff King
2018-07-26 8:12 ` Johannes Sixt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CABPp-BG_kYw1fWvq0YTTic7AV=nYuoKe9E4QMYVN0R_16xPKaw@mail.gmail.com' \
--to=newren@gmail.com \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=pclouds@gmail.com \
--cc=peff@peff.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).