linux-kernel - Re: [PATCH 1/1] suspend: make sync() on suspend-to-RAM optional

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:	Wed, 15 Jul 2015 08:43:21 +0200
From:	Pavel Machek <pavel@....cz>
To:	Len Brown <lenb@...nel.org>
Cc:	rjw@...ysocki.net, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, Len Brown <len.brown@...el.com>
Subject: Re: [PATCH 1/1] suspend: make sync() on suspend-to-RAM optional

On Tue 2015-07-14 22:24:51, Len Brown wrote:
> From: Len Brown <len.brown@...el.com>
> 
> The Linux kernel suspend path has traditionally invoked sys_sync().
> 
> But sys_sync() can be expensive, and some systems do not want
> to pay the cost of sys_sync() on every suspend.

Have you measured how expesive it can be, and why it is expensive?

> So make sys_sync on suspend optional.
> 
> Create sysfs attribute /sys/power/pm_suspend_do_sync.
> When set to 1, the kernel will sys_sync() on suspend,
> When set to 0, it will not.
> 
> This attribute can be changed by root at run-time.
> Kernel build parameter CONFIG_PM_SUSPEND_DO_SYNC_DEFAULT.
> As this is 1, by default, this patch does not change
> default behavior.

Why do you need CONFIG parameter?


									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
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/