linux-kernel - Re: [PATCH 0/5][RFC] Physical PCI slot objects

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: <20071113205939.GC22812@ldl.fc.hp.com>
Date:	Tue, 13 Nov 2007 13:59:39 -0700
From:	Alex Chiang <achiang@...com>
To:	Linas Vepstas <linas@...tin.ibm.com>
Cc:	Greg KH <greg@...ah.com>, gregkh@...e.de,
	kristen.c.accardi@...el.com, lenb@...nel.org, matthew@....cx,
	rick.jones2@...com, linux-kernel@...r.kernel.org,
	linux-pci@...ey.karlin.mff.cuni.cz,
	pcihpd-discuss@...ts.sourceforge.net, linux-acpi@...r.kernel.org
Subject: Re: [PATCH 0/5][RFC] Physical PCI slot objects

* Linas Vepstas <linas@...tin.ibm.com>:
> On Tue, Nov 13, 2007 at 09:01:29AM -0800, Greg KH wrote:
> > 
> > Also, some companies already provide userspace tools to get
> > all of this information about the different slots in a system
> > and what is where, from userspace, no kernel changes are
> > needed.  So, why add all this extra complexity to the kernel
> > if it is not needed?
> 
> Second that motion.... I don't get it. What are the goals of
> this patch, really?  Just to get a "slot geographical location"
> from the kernel?  

Yes, plus some general cleanups in the PCI hotplug space (more
patches queued up, pending the results of this series ;)

But to use the word "just" kinda implies that this is a trivial
feature that no one really cares about, which I'm not really sure
I agree with. Slot geographical location is important for
managability folks, who want to know which slot out of 192 (on a
big HP ia64 system, e.g.) that their failing network card might
be sitting in.

And again, we (HP ia64) need to get this information from the
kernel.

> I'm balancing the intellectual appeal of having a kernel struct
> for representing physical objects, against the headache of
> reading (debugging, modifying) code that has yet another struct
> doing yet another thing.  So far, the dread of future headaches
> is winning.

Well, hopefully, the future is cleaner, rather than messier. ;)

> On pseries systems, I deal with something called the
> "partitionable endpoint", which I think probably usually
> corresponds to physical slots, but I don't really know.  
>
> So, naively, the physical slot concept doesn't really map to
> what I have to work with; it just adds one more appendix to it
> all, one more thing to get confused about.

Sorry, I'm a bit ignorant about pseries -- what kind of name does
your PCI hotplug driver give to those slots? What shows up in
/sys/bus/pci/slots/?

> To be clear: above remarks are for the PowerPC boxes. I have no
> clue about how things work on the IBM Intel-based boxes.  And
> Greg's original "get IBM to agree" remark is about the
> Intel-based boxes.

A split house. I have no idea how Proliants work either. :)

Thanks.

/ac

-
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/