linux-kernel - Re: [patch] cpufreq: mark cpufreq_tsc() as core_initcall

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]

Message-ID: <20061124200419.GG5400@kernel.dk>
Date:	Fri, 24 Nov 2006 21:04:19 +0100
From:	Jens Axboe <jens.axboe@...cle.com>
To:	Oleg Nesterov <oleg@...sign.ru>
Cc:	"Paul E. McKenney" <paulmck@...ibm.com>,
	Alan Stern <stern@...land.harvard.edu>,
	linux-kernel@...r.kernel.org
Subject: Re: [patch] cpufreq: mark cpufreq_tsc() as core_initcall_sync

On Fri, Nov 24 2006, Oleg Nesterov wrote:
> Ok, synchronize_xxx() passed 1 hour rcutorture test on dual P-III.
> 
> It behaves the same as srcu but optimized for writers. The fast path
> for synchronize_xxx() is mutex_lock() + atomic_read() + mutex_unlock().
> The slow path is __wait_event(), no polling. However, the reader does
> atomic inc/dec on lock/unlock, and the counters are not per-cpu.
> 
> Jens, is it ok for you? Alan, Paul, what is your opinion?

This looks good from my end, much more appropriate than the current SRCU
code. Even if I could avoid synchronize_srcu() for most cases, when I
did have to issue it, the 3x synchronize_sched() was a performance
killer.

Thanks Oleg! And Alan and Paul for your excellent ideas.

-- 
Jens Axboe

-
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/