From: Jonathan Cameron <jic23@kernel.org>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: "Yury Norov" <yury.norov@gmail.com>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"David Laight" <David.Laight@aculab.com>,
"Joe Perches" <joe@perches.com>,
"Dennis Zhou" <dennis@kernel.org>,
"Emil Renner Berthing" <kernel@esmil.dk>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Matti Vaittinen" <matti.vaittinen@fi.rohmeurope.com>,
"Alexey Klimov" <aklimov@redhat.com>,
linux-kernel@vger.kernel.org,
"Lars-Peter Clausen" <lars@metafoo.de>,
"Alexandru Ardelean" <alexandru.ardelean@analog.com>,
"Nathan Chancellor" <nathan@kernel.org>,
linux-iio@vger.kernel.org
Subject: Re: [PATCH 04/49] iio: fix opencoded for_each_set_bit()
Date: Sat, 11 Jun 2022 14:50:34 +0100 [thread overview]
Message-ID: <20220611145034.07efd279@jic23-huawei> (raw)
In-Reply-To: <20220604164113.2ed4f681@jic23-huawei>
On Sat, 4 Jun 2022 16:41:13 +0100
Jonathan Cameron <jic23@kernel.org> wrote:
> On Fri, 11 Feb 2022 18:17:37 +0100
> Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote:
>
> > Le 10/02/2022 à 23:48, Yury Norov a écrit :
> > > iio_simple_dummy_trigger_h() is mostly an opencoded for_each_set_bit().
> > > Using for_each_set_bit() make code much cleaner, and more effective.
> > >
> > > Signed-off-by: Yury Norov <yury.norov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > > ---
> > > drivers/iio/dummy/iio_simple_dummy_buffer.c | 48 ++++++++-------------
> > > 1 file changed, 19 insertions(+), 29 deletions(-)
> > >
> > > diff --git a/drivers/iio/dummy/iio_simple_dummy_buffer.c b/drivers/iio/dummy/iio_simple_dummy_buffer.c
> > > index d81c2b2dad82..3bc1b7529e2a 100644
> > > --- a/drivers/iio/dummy/iio_simple_dummy_buffer.c
> > > +++ b/drivers/iio/dummy/iio_simple_dummy_buffer.c
> > > @@ -45,41 +45,31 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
> > > {
> > > struct iio_poll_func *pf = p;
> > > struct iio_dev *indio_dev = pf->indio_dev;
> > > + int i = 0, j;
> > > u16 *data;
> > >
> > > data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
> > > if (!data)
> > > goto done;
> > >
> > > - if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength)) {
> > > - /*
> > > - * Three common options here:
> > > - * hardware scans: certain combinations of channels make
> > > - * up a fast read. The capture will consist of all of them.
> > > - * Hence we just call the grab data function and fill the
> > > - * buffer without processing.
> > > - * software scans: can be considered to be random access
> > > - * so efficient reading is just a case of minimal bus
> > > - * transactions.
> > > - * software culled hardware scans:
> > > - * occasionally a driver may process the nearest hardware
> > > - * scan to avoid storing elements that are not desired. This
> > > - * is the fiddliest option by far.
> > > - * Here let's pretend we have random access. And the values are
> > > - * in the constant table fakedata.
> > > - */
> > > - int i, j;
> > > -
> > > - for (i = 0, j = 0;
> > > - i < bitmap_weight(indio_dev->active_scan_mask,
> > > - indio_dev->masklength);
> > > - i++, j++) {
> > > - j = find_next_bit(indio_dev->active_scan_mask,
> > > - indio_dev->masklength, j);
> > > - /* random access read from the 'device' */
> > > - data[i] = fakedata[j];
> > > - }
> > > - }
> > > + /*
> > > + * Three common options here:
> > > + * hardware scans: certain combinations of channels make
> > > + * up a fast read. The capture will consist of all of them.
> > > + * Hence we just call the grab data function and fill the
> > > + * buffer without processing.
> > > + * software scans: can be considered to be random access
> > > + * so efficient reading is just a case of minimal bus
> > > + * transactions.
> > > + * software culled hardware scans:
> > > + * occasionally a driver may process the nearest hardware
> > > + * scan to avoid storing elements that are not desired. This
> > > + * is the fiddliest option by far.
> > > + * Here let's pretend we have random access. And the values are
> > > + * in the constant table fakedata.
> > > + */
> >
> > Nitpicking: you could take advantage of the tab you save to use the full
> > width of the line and save some lines of code.
>
> Tweaked whilst applying.
>
> Sorry this one took so long. I marked it as a patch that I'd revisit if and
> tidy up if there was no v2 sent, but then managed to forget about it until
> I came to do a clean out of patchwork today.
>
> Anyhow, now applied to the togreg branch of iio.git - initially pushed out
> as testing for 0-day to see if we missed anything.
And dropped again during a rebase as a different version has gone upstream
through a pull request to Linus.
Whilst I have no strong opinion on that in general, I am a little grumpy
that a version was merged that was never posted to the mailing lists (that
I can find on lore.kernel.org.) Sure the changes were minor and easy to verify
as harmless, but none the less they should have been posted.
Jonathan
>
> Thanks,
>
> Jonathan
>
> >
> > Just my 2c.
> >
> > CJ
> >
> >
> > > + for_each_set_bit(j, indio_dev->active_scan_mask, indio_dev->masklength)
> > > + data[i++] = fakedata[j];
> > >
> > > iio_push_to_buffers_with_timestamp(indio_dev, data,
> > > iio_get_time_ns(indio_dev));
> >
>
next prev parent reply other threads:[~2022-06-11 13:41 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-10 22:48 [PATCH v4 00/49] bitmap: optimize bitmap_weight() usage Yury Norov
2022-02-10 22:48 ` [PATCH 01/49] net: dsa: don't use bitmap_weight() in b53_arl_read() Yury Norov
2022-02-10 22:48 ` [PATCH 02/49] net: systemport: don't use bitmap_weight() in bcm_sysport_rule_set() Yury Norov
2022-02-10 22:48 ` [PATCH 03/49] net: mellanox: fix open-coded for_each_set_bit() Yury Norov
2022-02-11 9:01 ` David Laight
2022-02-10 22:48 ` [PATCH 04/49] iio: fix opencoded for_each_set_bit() Yury Norov
2022-02-11 8:45 ` Andy Shevchenko
2022-02-11 17:17 ` Christophe JAILLET
2022-06-04 15:41 ` Jonathan Cameron
2022-06-11 13:50 ` Jonathan Cameron [this message]
2022-02-10 22:48 ` [RFC PATCH 05/49] qed: rework qed_rdma_bmap_free() Yury Norov
2022-02-11 8:48 ` Andy Shevchenko
2022-02-10 22:48 ` [PATCH 06/49] nds32: perf: replace bitmap_weight with bitmap_empty where appropriate Yury Norov
2022-02-10 22:48 ` [PATCH 07/49] KVM: x86: " Yury Norov
2022-02-11 16:34 ` Sean Christopherson
2022-02-11 17:13 ` Christophe JAILLET
2022-02-11 17:19 ` Sean Christopherson
2022-02-11 17:47 ` Yury Norov
2022-02-10 22:48 ` [PATCH 08/49] drm: " Yury Norov
2022-02-11 2:11 ` Dmitry Baryshkov
2022-02-10 22:48 ` [PATCH 09/49] ice: replace bitmap_weight with bitmap_empty Yury Norov
2022-02-10 22:48 ` [PATCH 10/49] octeontx2-pf: replace bitmap_weight with bitmap_empty where appropriate Yury Norov
2022-02-10 22:48 ` [PATCH 11/49] qed: replace bitmap_weight with bitmap_empty in qed_roce_stop() Yury Norov
2022-02-10 22:48 ` [PATCH 12/49] perf: replace bitmap_weight with bitmap_empty where appropriate Yury Norov
2022-02-11 10:25 ` Mark Rutland
2022-02-11 17:59 ` Yury Norov
2022-02-11 17:27 ` Christophe JAILLET
2022-02-11 23:23 ` Yury Norov
2022-02-10 22:48 ` [PATCH 13/49] perf tools: " Yury Norov
2022-02-10 22:48 ` [PATCH 14/49] arch/alpha: replace cpumask_weight with cpumask_empty " Yury Norov
2022-02-10 22:48 ` [PATCH 15/49] arch/ia64: " Yury Norov
2022-02-10 22:49 ` [PATCH 16/49] arch/x86: " Yury Norov
2022-04-10 20:42 ` [tip: x86/cleanups] x86: Replace cpumask_weight() with cpumask_empty() " tip-bot2 for Yury Norov
2022-02-10 22:49 ` [PATCH 17/49] cpufreq: replace cpumask_weight with cpumask_empty " Yury Norov
2022-02-11 4:30 ` Viresh Kumar
2022-02-11 5:17 ` Yury Norov
2022-02-10 22:49 ` [PATCH 18/49] drm/i915/pmu: " Yury Norov
2022-02-10 22:49 ` [PATCH 19/49] RDMA/hfi: " Yury Norov
2022-02-11 19:10 ` Jason Gunthorpe
2022-02-10 22:49 ` [PATCH 20/49] irq: mips: " Yury Norov
2022-04-10 20:34 ` [tip: irq/core] irqchip/bmips: Replace cpumask_weight() with cpumask_empty() tip-bot2 for Yury Norov
2022-02-10 22:49 ` [PATCH 21/49] genirq/affinity: replace cpumask_weight with cpumask_empty where appropriate Yury Norov
2022-04-10 20:27 ` [tip: irq/core] genirq/affinity: Replace cpumask_weight() with cpumask_empty() " tip-bot2 for Yury Norov
[not found] ` <573841649622719@mail.yandex.com>
2022-04-10 21:17 ` Yury Norov
2022-02-10 22:49 ` [PATCH 22/49] sched: replace cpumask_weight with cpumask_empty " Yury Norov
2022-02-11 10:19 ` Peter Zijlstra
2022-02-11 14:19 ` Yury Norov
2022-02-17 18:56 ` [tip: sched/core] " tip-bot2 for Yury Norov
2022-02-10 22:49 ` [PATCH 23/49] clocksource: replace cpumask_weight with cpumask_empty in clocksource.c Yury Norov
2022-04-10 20:35 ` [tip: timers/core] clocksource: Replace cpumask_weight() with cpumask_empty() tip-bot2 for Yury Norov
2022-02-10 22:49 ` [PATCH 24/49] mm/vmstat: replace cpumask_weight with cpumask_empty where appropriate Yury Norov
2022-02-11 10:39 ` Mike Rapoport
2022-02-10 22:49 ` [PATCH 25/49] arch/x86: replace nodes_weight with nodes_empty " Yury Norov
2022-04-10 20:42 ` [tip: x86/cleanups] x86/mm: Replace nodes_weight() with nodes_empty() " tip-bot2 for Yury Norov
2022-02-10 22:49 ` [PATCH 26/49] bitmap: add bitmap_weight_{cmp, eq, gt, ge, lt, le} functions Yury Norov
2022-02-10 22:49 ` [PATCH 27/49] arch/x86: replace bitmap_weight with bitmap_weight_{eq,gt,ge,lt,le} where appropriate Yury Norov
2022-02-10 22:49 ` [PATCH 28/49] iio: replace bitmap_weight() with bitmap_weight_{eq,gt} " Yury Norov
2022-02-10 22:49 ` [PATCH 29/49] memstick: replace bitmap_weight with bitmap_weight_eq " Yury Norov
2022-02-17 15:39 ` Ulf Hansson
2022-02-17 16:55 ` Yury Norov
2022-02-22 15:49 ` Ulf Hansson
2022-02-10 22:49 ` [PATCH 30/49] ixgbe: replace bitmap_weight with bitmap_weight_eq Yury Norov
2022-02-10 22:49 ` [PATCH 31/49] octeontx2-pf: replace bitmap_weight with bitmap_weight_{eq,gt} Yury Norov
2022-02-10 22:49 ` [PATCH 32/49] mlx4: replace bitmap_weight with bitmap_weight_{eq,gt,ge,lt,le} Yury Norov
2022-02-10 22:49 ` [PATCH 33/49] perf: replace bitmap_weight with bitmap_weight_eq for ThunderX2 Yury Norov
2022-02-11 10:30 ` Mark Rutland
2022-02-10 22:49 ` [PATCH 34/49] media: tegra-video: replace bitmap_weight with bitmap_weight_le Yury Norov
2022-04-28 7:31 ` Hans Verkuil
2022-02-10 22:49 ` [PATCH 35/49] cpumask: add cpumask_weight_{eq,gt,ge,lt,le} Yury Norov
2022-02-10 22:49 ` [PATCH 36/49] arch/ia64: replace cpumask_weight with cpumask_weight_eq in mm/tlb.c Yury Norov
2022-02-10 22:49 ` [PATCH 37/49] arch/mips: replace cpumask_weight with cpumask_weight_{eq, ...} where appropriate Yury Norov
2022-02-10 22:49 ` [PATCH 38/49] arch/powerpc: " Yury Norov
2022-02-11 4:10 ` Michael Ellerman
2022-02-10 22:49 ` [PATCH 39/49] arch/s390: replace cpumask_weight with cpumask_weight_eq " Yury Norov
2022-02-11 6:54 ` Sven Schnelle
2022-02-11 23:40 ` Yury Norov
2022-02-10 22:49 ` [PATCH 40/49] firmware: pcsi: replace cpumask_weight with cpumask_weight_eq Yury Norov
2022-02-11 9:45 ` Sudeep Holla
2022-02-11 10:32 ` Mark Rutland
2022-02-10 22:49 ` [PATCH 41/49] RDMA/hfi1: replace cpumask_weight with cpumask_weight_{eq, ...} where appropriate Yury Norov
2022-02-11 19:11 ` Jason Gunthorpe
2022-02-10 22:49 ` [PATCH 42/49] scsi: lpfc: replace cpumask_weight with cpumask_weight_gt Yury Norov
2022-02-10 22:49 ` [PATCH 43/49] soc/qman: replace cpumask_weight with cpumask_weight_lt Yury Norov
2022-02-10 22:49 ` [PATCH 44/49] nodemask: add nodemask_weight_{eq,gt,ge,lt,le} Yury Norov
2022-02-10 22:49 ` [PATCH 45/49] ACPI: replace nodes__weight with nodes_weight_ge for numa Yury Norov
2022-02-14 19:18 ` Rafael J. Wysocki
2022-02-14 19:34 ` Yury Norov
2022-02-14 19:45 ` Rafael J. Wysocki
2022-02-14 19:55 ` Yury Norov
2022-02-10 22:49 ` [PATCH 46/49] mm/mempolicy: replace nodes_weight with nodes_weight_eq Yury Norov
2022-02-11 10:40 ` Mike Rapoport
2022-02-11 17:44 ` Christophe JAILLET
2022-02-11 19:47 ` Yury Norov
2022-02-10 22:49 ` [PATCH 47/49] nodemask: add num_node_state_eq() Yury Norov
2022-02-11 10:41 ` Mike Rapoport
2022-02-10 22:49 ` [PATCH 48/49] tools: bitmap: sync bitmap_weight Yury Norov
2022-02-10 22:49 ` [PATCH 49/49] MAINTAINERS: add cpumask and nodemask files to BITMAP_API Yury Norov
2022-02-15 23:18 ` [PATCH v4 00/49] bitmap: optimize bitmap_weight() usage Will Deacon
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