From: Linus Torvalds <torvalds@linux-foundation.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] intel-iommu: fix build with CONFIG_BRANCH_TRACER=y
Date: Tue, 7 Apr 2009 07:50:38 -0700 (PDT) [thread overview]
Message-ID: <alpine.LFD.2.00.0904070743380.4010@localhost.localdomain> (raw)
In-Reply-To: <20090407090229.GA2467@elte.hu>
On Tue, 7 Apr 2009, Ingo Molnar wrote:
>
> Switch it to a braced group statement.
No, the way to do that is to just clean it up (or in the worst case just
add another set of parenthesis, not a statement expression).
That said, whoever made "if()" a macro should be shot. That
PROFILE_ALL_BRANCHES thing is crazy, crazy.
Anyway, in this case, I think
> #define for_each_active_iommu(i, drhd) \
> list_for_each_entry(drhd, &dmar_drhd_units, list) \
> - if (i=drhd->iommu, drhd->ignored) {} else
> + if (({i=drhd->iommu, drhd->ignored;})) {} else
Just do it like
if ( (i=drhd->iommu, drhd->ignored) ) {} else
is still not pretty, but better than using ({..}) I think. And just a
single set of parenthesis will protect the macro expansion.
But that '#define if(cond)' for the branch profiling is really the core
problem there. Wow. I never realized quite _how_ ugly tricks it played.
Linus
next prev parent reply other threads:[~2009-04-07 14:55 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1238839639.3560.37.camel@macbook.infradead.org>
2009-04-07 5:37 ` [GIT *] intel-iommu updates for 2.6.30 (second batch) Ingo Molnar
2009-04-07 5:42 ` Ingo Molnar
2009-04-07 5:52 ` David Woodhouse
2009-04-07 5:44 ` David Woodhouse
2009-04-07 5:48 ` Ingo Molnar
2009-04-07 5:52 ` Ingo Molnar
2009-04-07 6:04 ` David Woodhouse
2009-04-07 6:15 ` Ingo Molnar
2009-04-07 6:18 ` David Woodhouse
2009-04-07 8:49 ` Ingo Molnar
2009-04-07 9:02 ` [PATCH] intel-iommu: fix build with CONFIG_BRANCH_TRACER=y Ingo Molnar
2009-04-07 11:33 ` David Woodhouse
2009-04-07 12:14 ` Ingo Molnar
2009-04-07 12:44 ` David Woodhouse
2009-04-07 12:57 ` Ingo Molnar
2009-04-07 13:14 ` David Woodhouse
2009-04-07 14:54 ` Linus Torvalds
2009-04-07 14:59 ` Linus Torvalds
2009-04-07 15:12 ` Ingo Molnar
[not found] ` <f73f7ab80904071540w3d298c3bh386b46d5685f746e@mail.gmail.com>
2009-04-07 22:42 ` Kyle Moffett
2009-04-07 14:50 ` Linus Torvalds [this message]
2009-04-07 6:39 ` [GIT *] intel-iommu updates for 2.6.30 (second batch) Ingo Molnar
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