Re: [PATCH v2 2/2] kernel-trace: Less calls for iput() in create_trace_uprobe() after error detection
From: Julia Lawall
Date: Sun Nov 16 2014 - 14:35:22 EST
On Sun, 16 Nov 2014, Steven Rostedt wrote:
> On Sun, 16 Nov 2014 20:22:22 +0100
> SF Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx> wrote:
> > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > Date: Sun, 16 Nov 2014 19:49:39 +0100
> > The iput() function was called in three cases by the create_trace_uprobe()
> > function during error handling even if the passed variable contained still
> > a null pointer. This implementation detail could be improved by the
> > introduction of another jump label.
> The first patch is fine, and the only reason is to save the few bytes
> that the branch check might take. It's in a path that is unlikely to be
> hit so it is not a performance issue at all.
> This patch is useless. I rather not apply any patch than to create
> another jump that skips over the freeing of iput() just because we know
> inode is null. That's why we had the if (inode) in the first place.
> So Nack on this patch and I'll contemplate applying the first one. I
> probably will as it seems rather harmless.
I wuold have thought that one could have just returned, like in the cases
above... But maybe the printed message is useful.
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