netdev - Re: [PATCH 1/9] PCI: vpd handle longer delays in access (rev3)

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] [day] [month] [year] [list]

Date:	Tue, 9 Sep 2008 14:23:09 -0600
From:	Matthew Wilcox <matthew@....cx>
To:	Stephen Hemminger <shemminger@...tta.com>
Cc:	Jesse Barnes <jbarnes@...tuousgeek.org>, linux-pci@...r.kernel.org,
	netdev@...r.kernel.org
Subject: Re: [PATCH 1/9] PCI: vpd handle longer delays in access (rev3)

On Tue, Sep 09, 2008 at 11:20:41AM -0700, Stephen Hemminger wrote:
> Accessing the VPD area can take a long time.  The existing 
> VPD access code fails consistently on my hardware. There are comments
> in the SysKonnect vendor driver that it can take up to 13ms per word. 
> 
> Change the access routines to:
>   * use a mutex rather than spinning with IRQ's disabled and lock held
>   * have a much longer timeout
>   * call cond_resched while spinning

> -		udelay(10);
> +		if (fatal_signal_pending(current))
> +			return -EINTR;
> +		cond_resched();

We're back to the hammering on the pci bus problem again.  However,
cond_resched() does tell us whether we rescheduled!

		if (!cond_resched())
			udelay(10);

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html