Re: sparse_irq: userspace ABI breakage in -tip tree

Previous thread: Unified tracing buffer by Martin Bligh on Friday, September 19, 2008 - 2:33 pm. (122 messages)

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From: Arjan van de Ven
Date: Friday, September 19, 2008 - 3:53 pm

commit 70426a06a58561c401e64c5767d71a011d4b978b
Author: Yinghai Lu <yhlu.kernel@gmail.com>
Date:   Tue Aug 19 20:50:27 2008 -0700

    x86: make 32 bit to use sparse_irq

@@ -285,7 +303,7 @@ int show_interrupts(struct seq_file *p, void *v)
                action = desc->action;
                if (!action && !any_count)
                        goto skip;
-               seq_printf(p, "%3d: ",i);
+               seq_printf(p, "%#x: ",i);
 #ifndef CONFIG_SMP
                seq_printf(p, "%10u ", kstat_irqs(i));
 #else


this is a userspace ABI breakage; you're changing /proc/interrupts from
decimal to hex! This file is used by both humans and computer programs,
and the humans will get confused, but the computer programs will break.
Not a good idea to put into mainline.

(I'm not so convinced of sparse_irq as a whole to be honest, but that's
a different story)
--

From: Yinghai Lu
Date: Friday, September 19, 2008 - 5:10 pm

anything need to be addressed?

YH
--

From: Arjan van de Ven
Date: Friday, September 19, 2008 - 5:44 pm

On Fri, 19 Sep 2008 17:10:42 -0700

that's a minimum; someone (you?) needs to check if there are other
things changed in the format of this file....



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--

From: Yinghai Lu
Date: Friday, September 19, 2008 - 5:47 pm

does the ABI require the irq number in ascend sequence in /proc/interrupts?

also how about /proc/stat?

YH
--

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