linux-kernel - Re: [PATCH v2 1/1] drivers core: multi-threading device shutdown

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: <20180523104029.GC15312@amd>
Date:   Wed, 23 May 2018 12:40:29 +0200
From:   Pavel Machek <pavel@....cz>
To:     Pavel Tatashin <pasha.tatashin@...cle.com>
Cc:     steven.sistare@...cle.com, daniel.m.jordan@...cle.com,
        linux-kernel@...r.kernel.org, jeffrey.t.kirsher@...el.com,
        intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
        gregkh@...uxfoundation.org, alexander.duyck@...il.com,
        tobin@...orbit.com
Subject: Re: [PATCH v2 1/1] drivers core: multi-threading device shutdown

Hi!

> When system is rebooted, halted or kexeced device_shutdown() is
> called.
> 
> This function shuts down every single device by calling either:
> 
> 	dev->bus->shutdown(dev)
> 	dev->driver->shutdown(dev)
...
> Finally, with ixgbe_shutdown() it takes 0.37 for each device, but that time
> is spread all over the place, with bigger offenders:
> 
>     ixgbe_shutdown
>       __ixgbe_shutdown
>         ixgbe_close_suspend
>           ixgbe_down
>             ixgbe_init_hw_generic
>               ixgbe_reset_hw_X540
>                 msleep(100);                        0.104483472
>                 ixgbe_get_san_mac_addr_generic      0.048414851
>                 ixgbe_get_wwn_prefix_generic        0.048409893
>               ixgbe_start_hw_X540
>                 ixgbe_start_hw_generic
>                   ixgbe_clear_hw_cntrs_generic      0.048581502
>                   ixgbe_setup_fc_generic            0.024225800

ixgbe is network card, right? So ... it does not have any persistent
state and no moving parts, and there's no reason we could not "just
power it down"?
>  /*

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

Download attachment "signature.asc" of type "application/pgp-signature" (182 bytes)