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From: Jeff King <peff@peff.net>
To: Elijah Newren <newren@gmail.com>
Cc: Duy Nguyen <pclouds@gmail.com>, Git Mailing List <git@vger.kernel.org>
Subject: Re: 2.18.0 Regression: packing performance and effectiveness
Date: Fri, 20 Jul 2018 01:30:32 -0400	[thread overview]
Message-ID: <20180720053031.GA16126@sigill.intra.peff.net> (raw)
In-Reply-To: <20180720052829.GA3852@sigill.intra.peff.net>

On Fri, Jul 20, 2018 at 01:28:29AM -0400, Jeff King wrote:

> @@ -162,8 +166,10 @@ struct object_entry *packlist_alloc(struct packing_data *pdata,
>  
>  		if (!pdata->in_pack_by_idx)
>  			REALLOC_ARRAY(pdata->in_pack, pdata->nr_alloc);
> +		pack_delta_lock(pdata);
>  		if (pdata->delta_size)
>  			REALLOC_ARRAY(pdata->delta_size, pdata->nr_alloc);
> +		pack_delta_unlock(pdata);
>  	}

This made me wonder if in_pack_by_idx needs a similar lock. But
actually, I don't think either is necessary. We only allocate new
entries during the counting phase, not during the threaded delta search.

So this hunk could be dropped (and the system CPU benefit I saw is just
from reduced lock contention).

-Peff

  reply	other threads:[~2018-07-20  5:30 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 [this message]
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
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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