linux-kernel - Re: [PATCH] v3 RCU: the bloatwatch edition

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 28 Apr 2009 15:24:14 +0100
From:	David Howells <dhowells@...hat.com>
To:	paulmck@...ux.vnet.ibm.com
Cc:	dhowells@...hat.com, linux-kernel@...r.kernel.org, mingo@...e.hu,
	akpm@...ux-foundation.org, niv@...ibm.com, dvhltc@...ibm.com,
	lethal@...ux-sh.org, kernel@...tstofly.org, matthew@....cx
Subject: Re: [PATCH] v3 RCU: the bloatwatch edition

Paul E. McKenney <paulmck@...ux.vnet.ibm.com> wrote:

> This patch is a version of RCU designed for (!SMP && EMBEDDED)
> provided as a proof of concept of a small-footprint RCU implementation.
> In particular, the implementation of synchronize_rcu() is extremely
> lightweight and high performance.  It passes rcutorture testing in each
> of the four relevant configurations (combinations of NO_HZ and PREEMPT)
> on x86.  This saves about 900 bytes compared to Classic RCU, and a
> couple kilobytes compared to Hierarchical RCU:

On FRV, CLASSIC_RCU:

   text    data     bss     dec     hex filename
   2616     184       0    2800     af0 kernel/rcuclassic.o
    884      32      20     936     3a8 kernel/rcupdate.o

TREE_RCU:

   3940     328       0    4268    10ac kernel/rcutree.o
    884      32      20     936     3a8 kernel/rcupdate.o

TINY_RCU:

   1152      32       0    1184     4a0 kernel/rcutiny.o
    836      32      20     888     378 kernel/rcupdate.o

It works on my FRV board.

Possibly TINY_RCU could be shrunk a bit more by a judicious bit of inlining of
some of the very small functions.

Acked-by: David Howells <dhowells@...hat.com>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/