linux-kernel - Re: [RFC] killing the NR

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:	Sat, 17 Feb 2007 02:06:43 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc:	Arnd Bergmann <arnd@...db.de>,
	Russell King <rmk+lkml@....linux.org.uk>,
	linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andi Kleen <ak@...e.de>, Ingo Molnar <mingo@...e.hu>,
	Alan Cox <alan@...rguk.ukuu.org.uk>
Subject: Re: [RFC] killing the NR_IRQS arrays.

Benjamin Herrenschmidt <benh@...nel.crashing.org> writes:

> In addition, if we remove the numbers, archs will need basically the
> exact same services provided by the powerpc irq core for reverse mapping
> (going from a HW irq number on a given PIC back to an irq_desc *).

Ben you seem to be under misapprehension that except for the case of
ISA (0-16) the linux IRQ number is a hardware number.  It is an arbitrary
software enumeration, and I think it has been that way a very long time.

> Either using a linear array for simple PICs or a radix tree for
> platforms with very big interrupt numbers (BTW. I think we have lockless
> radix trees nowadays, I can remove the spinlocks to protect it in the
> powerpc remapper).

I can only tell you that my impression of this last is that all the
world's not a PPC.

I have a version of the x86 code with a partial conversion done and
I didn't need a reverse mapping.  What you call the hardware interrupt
number never happens to be interesting to me after the system is setup.

I do suspect there may be an interesting chunk of your ppc work that
probably makes sense as a library so other arches could use it.

Eric
-
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/