From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx2.redhat.com ([66.187.237.31]:32819 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753813AbZDFUVN (ORCPT ); Mon, 6 Apr 2009 16:21:13 -0400 Subject: Re: [PATCH] libertas: increase spi driver thread priority From: Dan Williams To: Anna Neal Cc: linux-wireless@vger.kernel.org, libertas-dev@lists.infradead.org, javier@cozybit.com In-Reply-To: <49d54fd9.1aba720a.5b57.ffffe3f6@mx.google.com> References: <49d54fd9.1aba720a.5b57.ffffe3f6@mx.google.com> Content-Type: text/plain Date: Mon, 06 Apr 2009 16:22:14 -0400 Message-Id: <1239049334.28824.10.camel@localhost.localdomain> (sfid-20090406_222115_484815_D63FE696) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, 2009-04-02 at 14:44 -0700, Anna Neal wrote: > Currently, the libertas main thread contends with the spi driver thread > in the TX path. To improve throughput, ensure that the driver thread > has higher scheduling priority than the libertas main thread. Do this > by making the libertas spi driver thread a low priority real time > thread. > > We measured an average throughput improvement of 13%. > > Signed-off-by: Anna Neal > Signed-off-by: Andrey Yurovsky Sure; looks fine to me. Acked-by: Dan Williams > --- > drivers/net/wireless/libertas/if_spi.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/wireless/libertas/if_spi.c b/drivers/net/wireless/libertas/if_spi.c > index 07311e7..97493e2 100644 > --- a/drivers/net/wireless/libertas/if_spi.c > +++ b/drivers/net/wireless/libertas/if_spi.c > @@ -1020,6 +1020,7 @@ static int __devinit if_spi_probe(struct spi_device *spi) > struct libertas_spi_platform_data *pdata = spi->dev.platform_data; > int err = 0; > u32 scratch; > + struct sched_param param = { .sched_priority = 1 }; > > lbs_deb_enter(LBS_DEB_SPI); > > @@ -1123,6 +1124,9 @@ static int __devinit if_spi_probe(struct spi_device *spi) > lbs_pr_err("error creating SPI thread: err=%d\n", err); > goto remove_card; > } > + if (sched_setscheduler(card->spi_thread, SCHED_FIFO, ¶m)) > + lbs_pr_err("Error setting scheduler, using default.\n"); > + > err = request_irq(spi->irq, if_spi_host_interrupt, > IRQF_TRIGGER_FALLING, "libertas_spi", card); > if (err) {