Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754899AbZAETLn (ORCPT ); Mon, 5 Jan 2009 14:11:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754576AbZAETLW (ORCPT ); Mon, 5 Jan 2009 14:11:22 -0500 Received: from brick.kernel.dk ([93.163.65.50]:27460 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754331AbZAETLV (ORCPT ); Mon, 5 Jan 2009 14:11:21 -0500 Date: Mon, 5 Jan 2009 20:10:16 +0100 From: Jens Axboe To: James Bottomley Cc: Bartlomiej Zolnierkiewicz , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Alan Cox Subject: Re: [PATCH] block: export SSD/non-rotational queue flag through sysfs Message-ID: <20090105191016.GU32491@kernel.dk> References: <200901051952.58029.bzolnier@gmail.com> <20090105185428.GS32491@kernel.dk> <200901052002.15984.bzolnier@gmail.com> <1231182486.3324.54.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1231182486.3324.54.camel@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4806 Lines: 137 On Mon, Jan 05 2009, James Bottomley wrote: > On Mon, 2009-01-05 at 20:02 +0100, Bartlomiej Zolnierkiewicz wrote: > > On Monday 05 January 2009, Jens Axboe wrote: > > > On Mon, Jan 05 2009, Bartlomiej Zolnierkiewicz wrote: > > > > From: Bartlomiej Zolnierkiewicz > > > > Subject: [PATCH] block: export SSD/non-rotational queue flag through sysfs > > > > > > > > For some devices (i.e. CFA ATA) we can't reliably detect whether > > > > the device is of rotational or non-rotational type so we need to > > > > leave the final decision about this setting to the user-space. > > > > > > I agree with that, was actually planning on doing that myself. > > > > > > > @@ -146,8 +167,8 @@ static ssize_t queue_nomerges_store(stru > > > > queue_flag_set(QUEUE_FLAG_NOMERGES, q); > > > > else > > > > queue_flag_clear(QUEUE_FLAG_NOMERGES, q); > > > > - > > > > spin_unlock_irq(q->queue_lock); > > > > + > > > > return ret; > > > > } > > > > > > > > > > Hmm? > > > > This is just a "bonus". :) > > > > > > @@ -210,6 +231,12 @@ static struct queue_sysfs_entry queue_hw > > > > .show = queue_hw_sector_size_show, > > > > }; > > > > > > > > +static struct queue_sysfs_entry queue_nonrot_entry = { > > > > + .attr = {.name = "nonrot", .mode = S_IRUGO | S_IWUSR }, > > > > + .show = queue_nonrot_show, > > > > + .store = queue_nonrot_store, > > > > +}; > > > > + > > > > > > Lets please use a better name for export reasons, non-rotational is a > > > lot better. Nobody will know what nonrot means :-) > > > > Yeah... > > > > From: Bartlomiej Zolnierkiewicz > > Subject: [PATCH v2] block: export SSD/non-rotational queue flag through sysfs > > > > For some devices (i.e. CFA ATA) we can't reliably detect whether > > the device is of rotational or non-rotational type so we need to > > leave the final decision about this setting to the user-space. > > > > As a bonus do a minor CodingStyle fixup in queue_nomerges_store(). > > > > Suggested-by: Alan Cox > > Signed-off-by: Bartlomiej Zolnierkiewicz > > --- > > block/blk-sysfs.c | 30 +++++++++++++++++++++++++++++- > > 1 file changed, 29 insertions(+), 1 deletion(-) > > > > Index: b/block/blk-sysfs.c > > =================================================================== > > --- a/block/blk-sysfs.c > > +++ b/block/blk-sysfs.c > > @@ -130,6 +130,27 @@ static ssize_t queue_max_hw_sectors_show > > return queue_var_show(max_hw_sectors_kb, (page)); > > } > > > > +static ssize_t queue_nonrot_show(struct request_queue *q, char *page) > > +{ > > + return queue_var_show(blk_queue_nonrot(q), page); > > +} > > + > > +static ssize_t queue_nonrot_store(struct request_queue *q, const char *page, > > + size_t count) > > +{ > > + unsigned long nm; > > + ssize_t ret = queue_var_store(&nm, page, count); > > + > > + spin_lock_irq(q->queue_lock); > > + if (nm) > > + queue_flag_set(QUEUE_FLAG_NONROT, q); > > + else > > + queue_flag_clear(QUEUE_FLAG_NONROT, q); > > + spin_unlock_irq(q->queue_lock); > > + > > + return ret; > > +} > > + > > static ssize_t queue_nomerges_show(struct request_queue *q, char *page) > > { > > return queue_var_show(blk_queue_nomerges(q), page); > > @@ -146,8 +167,8 @@ static ssize_t queue_nomerges_store(stru > > queue_flag_set(QUEUE_FLAG_NOMERGES, q); > > else > > queue_flag_clear(QUEUE_FLAG_NOMERGES, q); > > - > > spin_unlock_irq(q->queue_lock); > > + > > return ret; > > } > > > > @@ -210,6 +231,12 @@ static struct queue_sysfs_entry queue_hw > > .show = queue_hw_sector_size_show, > > }; > > > > +static struct queue_sysfs_entry queue_nonrot_entry = { > > + .attr = {.name = "non-rotational", .mode = S_IRUGO | S_IWUSR }, > > + .show = queue_nonrot_show, > > + .store = queue_nonrot_store, > > +}; > > + > > static struct queue_sysfs_entry queue_nomerges_entry = { > > .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, > > .show = queue_nomerges_show, > > @@ -229,6 +256,7 @@ static struct attribute *default_attrs[] > > &queue_max_sectors_entry.attr, > > &queue_iosched_entry.attr, > > &queue_hw_sector_size_entry.attr, > > + &queue_nonrot_entry.attr, > > &queue_nomerges_entry.attr, > > &queue_rq_affinity_entry.attr, > > NULL, > > Almost all block devices might find this useful. Ought not this flag to > be in the block layer appearing under /sys/block/? The block layer only uses it for scheduling purposes, in which case it fits well in queue/ since you need the io scheduler. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/