From: Bart Van Assche <Bart.VanAssche@sandisk.com>
To: "paolo.valente@linaro.org" <paolo.valente@linaro.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"fchecconi@gmail.com" <fchecconi@gmail.com>,
"linus.walleij@linaro.org" <linus.walleij@linaro.org>,
"axboe@kernel.dk" <axboe@kernel.dk>,
"avanzini.arianna@gmail.com" <avanzini.arianna@gmail.com>,
"broonie@kernel.org" <broonie@kernel.org>,
"tj@kernel.org" <tj@kernel.org>,
"ulf.hansson@linaro.org" <ulf.hansson@linaro.org>
Subject: Re: [PATCH RFC 01/14] block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler
Date: Sat, 18 Mar 2017 15:24:34 +0000 [thread overview]
Message-ID: <1489850658.2339.1.camel@sandisk.com> (raw)
In-Reply-To: <0B1F1CFD-C8AB-442D-B5C6-426D19B1FBA3@linaro.org>
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WARNING: multiple messages have this Message-ID (diff)
From: Bart Van Assche <Bart.VanAssche@sandisk.com>
To: "paolo.valente@linaro.org" <paolo.valente@linaro.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"fchecconi@gmail.com" <fchecconi@gmail.com>,
"linus.walleij@linaro.org" <linus.walleij@linaro.org>,
"axboe@kernel.dk" <axboe@kernel.dk>,
"avanzini.arianna@gmail.com" <avanzini.arianna@gmail.com>,
"broonie@kernel.org" <broonie@kernel.org>,
"tj@kernel.org" <tj@kernel.org>,
"ulf.hansson@linaro.org" <ulf.hansson@linaro.org>
Subject: Re: [PATCH RFC 01/14] block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler
Date: Sat, 18 Mar 2017 15:24:34 +0000 [thread overview]
Message-ID: <1489850658.2339.1.camel@sandisk.com> (raw)
In-Reply-To: <0B1F1CFD-C8AB-442D-B5C6-426D19B1FBA3@linaro.org>
On Sat, 2017-03-18 at 08:08 -0400, Paolo Valente wrote:
> > Il giorno 06 mar 2017, alle ore 14:40, Bart Van Assche <bart.vanassche@sandisk.com> ha scritto:
> > > +#define BFQ_BFQQ_FNS(name) \
> > > +static void bfq_mark_bfqq_##name(struct bfq_queue *bfqq) \
> > > +{ \
> > > + (bfqq)->flags |= (1 << BFQ_BFQQ_FLAG_##name); \
> > > +} \
> > > +static void bfq_clear_bfqq_##name(struct bfq_queue *bfqq) \
> > > +{ \
> > > + (bfqq)->flags &= ~(1 << BFQ_BFQQ_FLAG_##name); \
> > > +} \
> > > +static int bfq_bfqq_##name(const struct bfq_queue *bfqq) \
> > > +{ \
> > > + return ((bfqq)->flags & (1 << BFQ_BFQQ_FLAG_##name)) != 0; \
> > > +}
> >
> > Are the bodies of the above functions duplicates of __set_bit(),
> > __clear_bit() and test_bit()?
>
> Yes. We wrapped them into functions, because writing mark_flag_name
> seemed more readable than writing the implementation of the marking of the
> flag.
Please do not open-code __set_bit(), __clear_bit() and test_bit() but use
these macros instead.
> > > + } else
> > > + /*
> > > + * Async queues get always the maximum possible
> > > + * budget, as for them we do not care about latency
> > > + * (in addition, their ability to dispatch is limited
> > > + * by the charging factor).
> > > + */
> > > + budget = bfqd->bfq_max_budget;
> > > +
> >
> > Please balance braces. Checkpatch should have warned about the use of "}
> > else" instead of "} else {".
>
> No warning, I guess because the body of the else contains only a
> simple instruction. Just to learn for the future: what's the
> rationale for adding braces here, but not imposing braces everywhere
> for single-instruction bodies?
It's a general style recommendation for all kernel code: if braces are used
for one side of an if-statement, also use braces for the other side, and
definitely if that other side consists of multiple lines due to a comment.
Bart.
next prev parent reply other threads:[~2017-03-18 15:24 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-04 16:01 [PATCH RFC 00/14] Add the BFQ I/O Scheduler to blk-mq Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 01/14] block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler Paolo Valente
2017-03-05 15:16 ` Jens Axboe
2017-03-05 16:02 ` Paolo Valente
2017-03-05 16:02 ` Paolo Valente
2017-03-06 20:46 ` Jens Axboe
2017-03-14 11:28 ` Paolo Valente
2017-03-14 11:28 ` Paolo Valente
2017-03-06 19:40 ` Bart Van Assche
2017-03-06 19:40 ` Bart Van Assche
2017-03-14 14:18 ` Paolo Valente
2017-03-14 14:18 ` Paolo Valente
2017-03-18 12:08 ` Paolo Valente
2017-03-18 12:08 ` Paolo Valente
2017-03-18 15:24 ` Bart Van Assche [this message]
2017-03-18 15:24 ` Bart Van Assche
2017-03-19 11:45 ` Paolo Valente
2017-03-19 11:45 ` Paolo Valente
2017-03-07 23:22 ` Jens Axboe
2017-03-18 12:41 ` Paolo Valente
2017-03-18 12:41 ` Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 02/14] block, bfq: add full hierarchical scheduling and cgroups support Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 03/14] block, bfq: improve throughput boosting Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 04/14] block, bfq: modify the peak-rate estimator Paolo Valente
2017-03-07 0:47 ` Bart Van Assche
2017-03-07 0:47 ` Bart Van Assche
2017-03-04 16:01 ` [PATCH RFC 05/14] block, bfq: add more fairness with writes and slow processes Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 06/14] block, bfq: improve responsiveness Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 07/14] block, bfq: reduce I/O latency for soft real-time applications Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 08/14] block, bfq: preserve a low latency also with NCQ-capable drives Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 09/14] block, bfq: reduce latency during request-pool saturation Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 10/14] block, bfq: add Early Queue Merge (EQM) Paolo Valente
2017-03-07 17:44 ` Jens Axboe
2017-03-15 12:01 ` Paolo Valente
2017-03-15 12:01 ` Paolo Valente
2017-03-15 15:47 ` Jens Axboe
2017-03-15 16:30 ` Jens Axboe
2017-03-15 16:59 ` Paolo Valente
2017-03-15 16:59 ` Paolo Valente
2017-03-15 21:00 ` Jens Axboe
2017-03-18 10:33 ` Paolo Valente
2017-03-18 10:33 ` Paolo Valente
2017-03-15 16:56 ` Jens Axboe
2017-03-15 17:02 ` Paolo Valente
2017-03-15 17:02 ` Paolo Valente
2017-03-15 21:01 ` Jens Axboe
2017-03-04 16:01 ` [PATCH RFC 11/14] block, bfq: reduce idling only in symmetric scenarios Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 12/14] block, bfq: boost the throughput on NCQ-capable flash-based devices Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 13/14] block, bfq: boost the throughput with random I/O on NCQ-capable HDDs Paolo Valente
2017-03-07 0:54 ` Bart Van Assche
2017-03-07 0:54 ` Bart Van Assche
2017-03-14 14:12 ` Paolo Valente
2017-03-14 14:12 ` Paolo Valente
2017-03-04 16:01 ` [PATCH RFC 14/14] block, bfq: handle bursts of queue activations Paolo Valente
2017-03-06 7:43 ` [PATCH RFC 00/14] Add the BFQ I/O Scheduler to blk-mq Markus Trippelsdorf
2017-03-31 13:27 ` Paolo Valente
2017-03-31 13:27 ` Paolo Valente
2017-03-07 0:22 ` Bart Van Assche
2017-03-07 0:22 ` Bart Van Assche
2017-03-14 14:12 ` Paolo Valente
2017-03-14 14:12 ` Paolo Valente
2017-03-07 1:00 ` Bart Van Assche
2017-03-07 1:00 ` Bart Van Assche
2017-03-14 15:35 ` Paolo Valente
2017-03-14 15:35 ` Paolo Valente
2017-03-14 15:42 ` Jens Axboe
2017-03-14 16:32 ` Bart Van Assche
2017-03-14 16:32 ` Bart Van Assche
2017-03-18 10:52 ` Paolo Valente
2017-03-18 10:52 ` Paolo Valente
2017-03-18 17:09 ` Linus Walleij
2017-03-18 17:46 ` Bart Van Assche
2017-03-18 17:46 ` Bart Van Assche
2017-03-18 20:46 ` Linus Walleij
2017-03-19 12:14 ` Paolo Valente
2017-03-19 12:14 ` Paolo Valente
2017-03-20 18:40 ` Jens Axboe
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