From: Junio C Hamano <gitster@pobox.com>
To: Duy Nguyen <pclouds@gmail.com>
Cc: Elijah Newren <newren@gmail.com>,
Git Mailing List <git@vger.kernel.org>, Jeff King <peff@peff.net>
Subject: Re: 2.18.0 Regression: packing performance and effectiveness
Date: Thu, 19 Jul 2018 12:25:44 -0700 [thread overview]
Message-ID: <xmqqlga7do3r.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <20180719151640.GA24997@duynguyen.home> (Duy Nguyen's message of "Thu, 19 Jul 2018 17:16:42 +0200")
Duy Nguyen <pclouds@gmail.com> writes:
> @@ -330,20 +330,27 @@ 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)
> {
> - if (e->delta_size_valid)
> + if (!pack->delta_size)
> return e->delta_size_;
> - return oe_size(pack, e);
> + return pack->delta_size[e - pack->objects];
> }
>
> +void oe_prepare_delta_size_array(struct packing_data *pack);
> static inline void oe_set_delta_size(struct packing_data *pack,
> struct object_entry *e,
> unsigned long size)
> {
> e->delta_size_ = size;
> - e->delta_size_valid = e->delta_size_ == size;
> - if (!e->delta_size_valid && size != oe_size(pack, e))
> - BUG("this can only happen in check_object() "
> - "where delta size is the same as entry size");
> + if (!pack->delta_size && e->delta_size_ == size)
> + return;
> + /*
> + * 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)
> + oe_prepare_delta_size_array(pack);
> + pack->delta_size[e - pack->objects] = size;
> }
Imagine that you create a delta and set its size (which happens to
fit in the entry) and then create another whose size does not fit in
the entry. How does oe_delta_size() know not to look at
pack->delta_size[] and instead look at e->delta_size_ when it wants
to know the delta for the first one? IOW, shouldn't there be a
"backfill" procedure when oe_set_delta_size() notices that we now
switch to pack->delta_size[] array?
next prev parent reply other threads:[~2018-07-19 19:26 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 [this message]
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
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
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