From: Dominique Martinet <asmadeus@codewreck.org>
To: Greg Kurz <groug@kaod.org>
Cc: Matthew Wilcox <willy@infradead.org>,
Latchesar Ionkov <lucho@ionkov.net>,
Eric Van Hensbergen <ericvh@gmail.com>,
linux-kernel@vger.kernel.org, Ron Minnich <rminnich@sandia.gov>,
linux-fsdevel@vger.kernel.org,
v9fs-developer@lists.sourceforge.net
Subject: Re: [V9fs-developer] [PATCH v2 4/6] 9p: Embed wait_queue_head into p9_req_t
Date: Thu, 12 Jul 2018 16:40:12 +0200 [thread overview]
Message-ID: <20180712144012.GA21574@nautica> (raw)
In-Reply-To: <20180712163649.36057b6e@bahia.lan>
Greg Kurz wrote on Thu, Jul 12, 2018:
> This is true when all tags have been used at least once. But the current code
> lazily allocates the wait_queue_head_t, ie, only when a tag is used for the
> first time. Your patch causes a full row of wait_quest_head_t to be pre-allocated.
>
> ie, P9_ROW_MAXTAG * 24 = 255 * 24 = 6120
>
> instead of (P9_ROW_MAXTAG * 8) + 24 = 255 * 8 + 24 = 2064
>
> This is nearly a page of allocated memory that might be never used.
>
> Not sure if this is a problem though...
I thought the exact same, but the next patch in the serie removes that
array and allocates even more lazily with a slab, so this was a
no-brainer :)
--
Dominique Martinet
next prev parent reply other threads:[~2018-07-12 14:50 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-11 21:02 [PATCH v2 0/6] 9p: Use IDRs more effectively Matthew Wilcox
2018-07-11 21:02 ` [PATCH v2 1/6] 9p: Fix comment on smp_wmb Matthew Wilcox
2018-07-12 11:55 ` [V9fs-developer] " Greg Kurz
2018-07-11 21:02 ` [PATCH v2 2/6] 9p: Change p9_fid_create calling convention Matthew Wilcox
2018-07-12 2:15 ` [V9fs-developer] " piaojun
2018-07-12 11:56 ` Greg Kurz
2018-07-13 1:18 ` jiangyiwen
2018-07-11 21:02 ` [PATCH v2 3/6] 9p: Replace the fidlist with an IDR Matthew Wilcox
2018-07-12 11:17 ` Dominique Martinet
2018-07-12 11:23 ` Matthew Wilcox
2018-07-12 11:30 ` Dominique Martinet
2018-07-13 2:05 ` [V9fs-developer] " jiangyiwen
2018-07-13 2:48 ` Matthew Wilcox
2018-07-11 21:02 ` [PATCH v2 4/6] 9p: Embed wait_queue_head into p9_req_t Matthew Wilcox
2018-07-12 14:36 ` [V9fs-developer] " Greg Kurz
2018-07-12 14:40 ` Dominique Martinet [this message]
2018-07-12 14:59 ` Greg Kurz
2018-07-11 21:02 ` [PATCH v2 5/6] 9p: Use a slab for allocating requests Matthew Wilcox
2018-07-18 10:05 ` Dominique Martinet
2018-07-18 11:49 ` Matthew Wilcox
2018-07-18 12:46 ` Dominique Martinet
2018-07-23 11:52 ` Greg Kurz
2018-07-23 12:25 ` Dominique Martinet
2018-07-23 14:24 ` Greg Kurz
2018-07-30 9:31 ` Dominique Martinet
2018-07-30 9:34 ` [PATCH 1/2] net/9p: embed fcall in req to round down buffer allocs Dominique Martinet
2018-07-30 9:34 ` [PATCH 2/2] net/9p: add a per-client fcall kmem_cache Dominique Martinet
2018-07-31 1:18 ` [V9fs-developer] " piaojun
2018-07-31 1:35 ` Dominique Martinet
2018-07-31 1:45 ` piaojun
2018-07-31 2:46 ` Matthew Wilcox
2018-07-31 4:17 ` Dominique Martinet
2018-08-01 14:28 ` [V9fs-developer] " Greg Kurz
2018-08-01 15:22 ` Dominique Martinet
2018-07-31 0:55 ` [V9fs-developer] [PATCH 1/2] net/9p: embed fcall in req to round down buffer allocs piaojun
2018-07-31 1:12 ` Dominique Martinet
2018-07-31 1:28 ` piaojun
2018-08-01 14:14 ` Greg Kurz
2018-08-01 14:38 ` Dominique Martinet
2018-08-01 15:03 ` Greg Kurz
2018-08-02 2:37 ` [PATCH v2 " Dominique Martinet
2018-08-02 2:37 ` [PATCH v2 2/2] net/9p: add a per-client fcall kmem_cache Dominique Martinet
2018-08-02 4:58 ` [V9fs-developer] " Dominique Martinet
2018-08-02 9:23 ` [PATCH v2 1/2] net/9p: embed fcall in req to round down buffer allocs Greg Kurz
2018-08-02 22:03 ` Dominique Martinet
2018-08-09 14:33 ` [PATCH v3 " Dominique Martinet
2018-08-09 14:33 ` [PATCH v3 2/2] net/9p: add a per-client fcall kmem_cache Dominique Martinet
2018-08-10 1:23 ` piaojun
2018-08-10 1:41 ` Dominique Martinet
2018-08-10 1:49 ` piaojun
2018-08-10 0:47 ` [PATCH v3 1/2] net/9p: embed fcall in req to round down buffer allocs piaojun
2018-07-11 21:02 ` [PATCH v2 6/6] 9p: Remove p9_idpool Matthew Wilcox
2018-07-11 23:37 ` [PATCH v2 0/6] 9p: Use IDRs more effectively Dominique Martinet
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