From: Michal Hocko <mhocko@kernel.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org,
Scott Cheloha <cheloha@linux.vnet.ibm.com>,
David Hildenbrand <david@redhat.com>,
nathanl@linux.ibm.com, ricklind@linux.vnet.ibm.com,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v3] drivers/base/memory.c: cache blocks in radix tree to accelerate lookup
Date: Thu, 9 Jan 2020 09:49:55 +0100 [thread overview]
Message-ID: <20200109084955.GI4951@dhcp22.suse.cz> (raw)
In-Reply-To: <20200107214801.GN32178@dhcp22.suse.cz>
On Tue 07-01-20 22:48:04, Michal Hocko wrote:
> [Cc Andrew]
>
> On Tue 17-12-19 13:32:38, Scott Cheloha wrote:
> > Searching for a particular memory block by id is slow because each block
> > device is kept in an unsorted linked list on the subsystem bus.
>
> Noting that this is O(N^2) would be useful.
>
> > Lookup is much faster if we cache the blocks in a radix tree.
>
> While this is really easy and straightforward, is there any reason why
> subsys_find_device_by_id has to use such a slow lookup? I suspect nobody
> simply needed a more optimized data structure for that purpose yet.
> Would it be too hard to use radix tree for all lookups rather than
> adding a shadow copy for memblocks?
Greg, Rafael, this seems to be your domain. Do you have any opinion on
this?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-01-09 8:50 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 19:25 [PATCH] memory subsystem: cache memory " Scott Cheloha
2019-11-21 9:34 ` David Hildenbrand
2019-11-21 9:35 ` David Hildenbrand
2019-11-21 19:59 ` [PATCH v2] drivers/base/memory.c: cache " Scott Cheloha
2019-11-25 6:36 ` kbuild test robot
2019-12-17 19:32 ` [PATCH v3] " Scott Cheloha
2019-12-18 9:00 ` David Hildenbrand
2019-12-19 17:33 ` Scott Cheloha
2019-12-20 10:50 ` David Hildenbrand
2019-12-19 18:09 ` Nathan Lynch
2020-01-07 21:48 ` Michal Hocko
2020-01-08 13:36 ` David Hildenbrand
2020-01-08 14:21 ` Michal Hocko
2020-01-08 15:23 ` David Hildenbrand
2020-01-09 8:49 ` Michal Hocko [this message]
2020-01-09 8:56 ` Greg Kroah-Hartman
2020-01-09 9:19 ` Michal Hocko
2020-01-09 9:24 ` David Hildenbrand
2020-01-09 9:31 ` David Hildenbrand
2020-01-09 9:41 ` Greg Kroah-Hartman
2020-01-09 9:33 ` Greg Kroah-Hartman
2020-01-09 9:50 ` Michal Hocko
2020-01-09 9:48 ` Michal Hocko
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