linux-kernel - Re: [RFC][PATCH] irq: remove IRQF

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:	Mon, 02 Mar 2009 16:59:48 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Matthew Wilcox <matthew@....cx>
Cc:	Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	lkml <linux-kernel@...r.kernel.org>,
	linux-arch <linux-arch@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [RFC][PATCH] irq: remove IRQF_DISABLED

On Mon, 2009-03-02 at 08:47 -0700, Matthew Wilcox wrote:
> On Mon, Mar 02, 2009 at 03:43:03PM +0100, Ingo Molnar wrote:
> > * Peter Zijlstra <peterz@...radead.org> wrote:
> > > Hi Linus,
> > > 
> > > Would you be willing to take such a patch?
> > > 
> > > Its a rather big one, but if you think its a good idea, I can 
> > > generate one against whatever tree is needed.
> > > 
> > > Provided I didn't break any !genirq stuff.. then again, that 
> > > might be a nice incentive to fix up those last few archs.
> > 
> > look good IMO. If there are no objections, and given that it 
> 
> Perhaps someone could explain why we want to remove it?  I just added
> it to AHCI for good reason, so I'd like to know why we think it should
> be taken away.
> 
> I added it because I was adding support for per-port interrupts.
> In the interrupt handler, we take the *host* lock (not the port lock).
> With multiple interrupt handlers per host, we would have to disable
> interrupts in the interrupt handler before taking the lock.  Which is
> foolish because we've just re-enabled interrupts in the genirq code.
> Specifying IRQF_DISABLED means we just run with interrupts disabled.
> 
> You can argue that libata/ahci should be using a per-port lock, and
> I wouldn't disagree.  But I'd still like to know why IRQF_DISABLED is
> being removed.

The idea is to mandate IRQF_DISABLED for everybody, and since it doesn't
do any good to have it a flag if you have it always enabled, remove
it ;-)



--
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/