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:	Mon, 1 Nov 2010 17:11:26 +0000
From:	Alan Cox <alan@...ux.intel.com>
To:	Ming Lei <tom.leiming@...il.com>
Cc:	Samu Onkalo <samu.p.onkalo@...ia.com>, gregkh@...e.de,
	hmh@....eng.br, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH] device-core: sysfs open - close notify

> Your patch may cause many unnecessary memory waste because
> most of drivers does not need attribute file .open/.close notifier.

Firstly there are not that many driver objects in a small system so it
wouldn't take that much to shift the balance the other way. Secondly
its becoming clear that every time a driver goes to runtime pm these
issues come up - even with things like configuration values for drivers
that need to wake the hardware and then silence it.

So the whole sysfs/open thing is going to keep haunting us with runtime
pm, the question is where to put the callbacks so we don't bloat stuff.
Clearly not per attribute or per sysfs node. One possibility would be
with the runtime pm stuff, but that would need a clean reliable way to
go sysfs->device->runtime_pm

There are also obvious hackish ways to handle it like passing a 0
length read to indicate close etc - they save memory but they are
asking for problems in future.

--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ