From: Junio C Hamano <gitster@pobox.com>
To: David Turner <dturner@twopensource.com>
Cc: git@vger.kernel.org, pclouds@gmail.com
Subject: Re: [PATCH 04/19] index-helper: new daemon for caching index and related stuff
Date: Wed, 09 Mar 2016 15:21:01 -0800 [thread overview]
Message-ID: <xmqqpov3fdb6.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <xmqqtwkffdus.fsf@gitster.mtv.corp.google.com> (Junio C. Hamano's message of "Wed, 09 Mar 2016 15:09:15 -0800")
Junio C Hamano <gitster@pobox.com> writes:
> David Turner <dturner@twopensource.com> writes:
>
>> From: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
>>
>> Instead of reading the index from disk and worrying about disk
>> corruption, the index is cached in memory (memory bit-flips happen
>> too, but hopefully less often). The result is faster read. Read time
>> is reduced by 70%.
>>
>> The biggest gain is not having to verify the trailing SHA-1, which
>> takes lots of time especially on large index files.
Come to think of it, wouldn't it be far less intrusive change to
just put the index on a ramdisk and skip the trailing SHA-1
verification, to obtain a similar result with the same trade off
(i.e. blindly trusting memory instead of being paranoid)?
next prev parent reply other threads:[~2016-03-09 23:21 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 18:36 [PATCH 00/19] index-helper, watchman David Turner
2016-03-09 18:36 ` [PATCH 01/19] trace.c: add GIT_TRACE_PACK_STATS for pack usage statistics David Turner
2016-03-09 22:58 ` Junio C Hamano
2016-03-10 0:05 ` David Turner
2016-03-10 10:59 ` Duy Nguyen
2016-03-09 18:36 ` [PATCH 02/19] read-cache.c: fix constness of verify_hdr() David Turner
2016-03-09 18:36 ` [PATCH 03/19] read-cache: allow to keep mmap'd memory after reading David Turner
2016-03-09 23:02 ` Junio C Hamano
2016-03-10 0:09 ` David Turner
2016-03-09 18:36 ` [PATCH 04/19] index-helper: new daemon for caching index and related stuff David Turner
2016-03-09 23:09 ` Junio C Hamano
2016-03-09 23:21 ` Junio C Hamano [this message]
2016-03-10 0:01 ` David Turner
2016-03-10 11:17 ` Duy Nguyen
2016-03-10 20:22 ` David Turner
2016-03-11 1:11 ` Duy Nguyen
2016-03-10 0:18 ` David Turner
2016-03-15 11:56 ` Duy Nguyen
2016-03-15 15:56 ` Junio C Hamano
2016-03-15 11:52 ` Duy Nguyen
2016-03-09 18:36 ` [PATCH 05/19] trace.c: add GIT_TRACE_INDEX_STATS for index statistics David Turner
2016-03-09 18:36 ` [PATCH 06/19] index-helper: add --strict David Turner
2016-03-09 18:36 ` [PATCH 07/19] daemonize(): set a flag before exiting the main process David Turner
2016-03-09 18:36 ` [PATCH 08/19] index-helper: add --detach David Turner
2016-03-09 18:36 ` [PATCH 09/19] index-helper: add Windows support David Turner
2016-03-16 11:42 ` Duy Nguyen
2016-03-17 12:18 ` Johannes Schindelin
2016-03-17 12:59 ` Duy Nguyen
2016-03-09 18:36 ` [PATCH 10/19] read-cache: add watchman 'WAMA' extension David Turner
2016-03-09 18:36 ` [PATCH 11/19] Add watchman support to reduce index refresh cost David Turner
2016-03-09 18:36 ` [PATCH 12/19] read-cache: allow index-helper to prepare shm before git reads it David Turner
2016-03-09 18:36 ` [PATCH 13/19] index-helper: use watchman to avoid refreshing index with lstat() David Turner
2016-03-09 18:36 ` [PATCH 14/19] update-index: enable/disable watchman support David Turner
2016-03-09 18:36 ` [PATCH 15/19] unpack-trees: preserve index extensions David Turner
2016-03-09 18:36 ` [PATCH 16/19] index-helper: rewrite pidfile after daemonizing David Turner
2016-03-09 18:36 ` [PATCH 17/19] index-helper: process management David Turner
2016-03-09 18:36 ` [PATCH 18/19] index-helper: autorun David Turner
2016-03-15 12:12 ` Duy Nguyen
2016-03-15 14:26 ` Johannes Schindelin
2016-03-16 11:37 ` Duy Nguyen
2016-03-16 18:11 ` David Turner
2016-03-16 18:27 ` Johannes Schindelin
2016-03-17 13:02 ` Duy Nguyen
2016-03-17 14:43 ` Johannes Schindelin
2016-03-17 18:31 ` David Turner
2016-03-18 0:50 ` Duy Nguyen
2016-03-18 7:14 ` Johannes Schindelin
2016-03-18 7:44 ` Duy Nguyen
2016-03-18 17:22 ` David Turner
2016-03-18 23:09 ` Duy Nguyen
2016-03-18 7:17 ` Johannes Schindelin
2016-03-18 7:34 ` Duy Nguyen
2016-03-18 15:57 ` Johannes Schindelin
2016-03-09 18:36 ` [PATCH 19/19] hack: watchman/untracked cache mashup David Turner
2016-03-15 12:31 ` Duy Nguyen
2016-03-17 0:56 ` David Turner
2016-03-17 13:06 ` Duy Nguyen
2016-03-17 18:08 ` David Turner
2016-03-29 17:09 ` [PATCH 00/19] index-helper, watchman Torsten Bögershausen
2016-03-29 21:51 ` David Turner
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