From: David Hildenbrand <david@redhat.com>
To: Scott Cheloha <cheloha@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org,
"Rafael J. Wysocki" <rafael@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: nathanl@linux.ibm.com, ricklind@linux.vnet.ibm.com,
mhocko@suse.com, Scott Cheloha <cheloha@linux.ibm.com>,
Donald Dutile <ddutile@redhat.com>
Subject: Re: [PATCH v4] drivers/base/memory.c: cache blocks in radix tree to accelerate lookup
Date: Wed, 15 Jan 2020 20:09:48 +0100 [thread overview]
Message-ID: <181caae3-ffb8-c745-a4c9-1aef93ea6dd5@redhat.com> (raw)
In-Reply-To: <20200109212516.17849-1-cheloha@linux.vnet.ibm.com>
On 09.01.20 22:25, Scott Cheloha wrote:
> Searching for a particular memory block by id is an O(n) operation
> because each memory block's underlying device is kept in an unsorted
> linked list on the subsystem bus.
>
> We can cut the lookup cost to O(log n) if we cache the memory blocks in
> a radix tree. With a radix tree cache in place both memory subsystem
> initialization and memory hotplug run palpably faster on systems with a
> large number of memory blocks.
>
> Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
> Acked-by: Michal Hocko <mhocko@suse.com>
Soooo,
I just learned that radix trees are nowadays only a wrapper for xarray
(for quite a while already!), and that the xarray interface shall be
used in new code.
include/linux/radix-tree.h:
/* Keep unconverted code working */
#define radix_tree_root xarray
[...]
Do we want to convert this code before sending it to Linus'? (resend
this patch, or a fixup on top)
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2020-01-15 19:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191217193238-1-cheloha@linux.vnet.ibm.com>
2020-01-09 21:19 ` [PATCH] drivers/base/memory.c: cache blocks in radix tree to accelerate lookup Scott Cheloha
2020-01-09 21:30 ` Michal Hocko
2020-01-09 21:25 ` [PATCH v4] " Scott Cheloha
2020-01-09 22:00 ` Andrew Morton
2020-01-09 22:17 ` David Hildenbrand
2020-01-09 22:27 ` Andrew Morton
2020-01-09 22:35 ` David Hildenbrand
2020-01-10 9:32 ` David Hildenbrand
2020-01-10 11:31 ` Michal Hocko
2020-01-15 19:09 ` David Hildenbrand [this message]
2020-01-16 15:22 ` Michal Hocko
2020-01-16 15:28 ` David Hildenbrand
2020-01-16 16:17 ` David Hildenbrand
2020-01-17 9:35 ` Michal Hocko
2020-01-20 9:15 ` David Hildenbrand
2020-01-21 12:30 ` Michal Hocko
2020-01-16 17:17 ` Don Dutile
2020-01-21 23:10 ` [PATCH v5] drivers/base/memory.c: cache memory blocks in xarray " Scott Cheloha
2020-01-22 10:43 ` David Hildenbrand
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=181caae3-ffb8-c745-a4c9-1aef93ea6dd5@redhat.com \
--to=david@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=cheloha@linux.ibm.com \
--cc=cheloha@linux.vnet.ibm.com \
--cc=ddutile@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mhocko@suse.com \
--cc=nathanl@linux.ibm.com \
--cc=rafael@kernel.org \
--cc=ricklind@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).