Re: [PATCH v8 06/22] perf arm-spe: Refactor printing string to buffer

From: Dave Martin <Dave.Martin@arm.com>
To: "leo.yan@linaro.org" <leo.yan@linaro.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Andre Przywara <Andre.Przywara@arm.com>,
	James Clark <James.Clark@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <Mark.Rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Al Grant <Al.Grant@arm.com>, Wei Li <liwei391@huawei.com>,
	John Garry <john.garry@huawei.com>, Will Deacon <will@kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v8 06/22] perf arm-spe: Refactor printing string to buffer
Date: Wed, 11 Nov 2020 15:58:27 +0000	[thread overview]
Message-ID: <20201111155826.GN6882@arm.com> (raw)
In-Reply-To: <20201111155320.GM6882@arm.com>

On Wed, Nov 11, 2020 at 03:53:20PM +0000, Dave Martin wrote:
> On Wed, Nov 11, 2020 at 07:11:33AM +0000, Leo Yan wrote:
> > When outputs strings to the decoding buffer with function snprintf(),
> > SPE decoder needs to detects if any error returns from snprintf() and if
> > so needs to directly bail out.  If snprintf() returns success, it needs
> > to update buffer pointer and reduce the buffer length so can continue to
> > output the next string into the consequent memory space.
> > 
> > This complex logics are spreading in the function arm_spe_pkt_desc() so
> > there has many duplicate codes for handling error detecting, increment
> > buffer pointer and decrement buffer size.
> > 
> > To avoid the duplicate code, this patch introduces a new helper function
> > arm_spe_pkt_snprintf() which is used to wrap up the complex logics, and
> > it's used by the caller arm_spe_pkt_desc().
> > 
> > This patch also moves the variable 'blen' as the function's local
> > variable, this allows to remove the unnecessary braces and improve the
> > readability.
> > 
> > Suggested-by: Dave Martin <Dave.Martin@arm.com>
> > Signed-off-by: Leo Yan <leo.yan@linaro.org>
> > Reviewed-by: Andre Przywara <andre.przywara@arm.com>
> 
> Mostly looks fine to me now, thought there are a few potentionalu
> issues -- comments below.

Hmm, looks like patch 7 anticipated some of my comments here.

Rather than fixing up patch 6, maybe it would be better to squash these
patches together after all...  sorry!

[...]

Cheers
---Dave