From: Bart Van Assche <bvanassche@acm.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org,
Christoph Hellwig <hch@lst.de>,
Adrian Hunter <adrian.hunter@intel.com>,
Avri Altman <avri.altman@wdc.com>,
Bart Van Assche <bvanassche@acm.org>,
Ming Lei <ming.lei@redhat.com>, Keith Busch <kbusch@kernel.org>
Subject: [PATCH v2 2/8] block: Support configuring limits below the page size
Date: Wed, 23 Nov 2022 12:57:34 -0800 [thread overview]
Message-ID: <20221123205740.463185-3-bvanassche@acm.org> (raw)
In-Reply-To: <20221123205740.463185-1-bvanassche@acm.org>
Allow block drivers to configure the following if
CONFIG_BLK_SUB_PAGE_SEGMENTS=y:
* Maximum number of hardware sectors values smaller than
PAGE_SIZE >> SECTOR_SHIFT. With PAGE_SIZE = 4096 this means that values
below 8 become supported.
* A maximum segment size smaller than the page size. This is most useful
for page sizes above 4096 bytes.
The behavior of the block layer is not modified if
CONFIG_BLK_SUB_PAGE_SEGMENTS=n.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
block/blk-settings.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 0477c4d527fe..f9d78dea0291 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -122,12 +122,14 @@ EXPORT_SYMBOL(blk_queue_bounce_limit);
void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
{
struct queue_limits *limits = &q->limits;
+ unsigned int min_max_hw_sectors = blk_queue_sub_page_segments(q) ? 1 :
+ PAGE_SIZE >> SECTOR_SHIFT;
unsigned int max_sectors;
- if ((max_hw_sectors << 9) < PAGE_SIZE) {
- max_hw_sectors = 1 << (PAGE_SHIFT - 9);
- printk(KERN_INFO "%s: set to minimum %d\n",
- __func__, max_hw_sectors);
+ if (max_hw_sectors < min_max_hw_sectors) {
+ max_hw_sectors = min_max_hw_sectors;
+ printk(KERN_INFO "%s: set to minimum %u\n", __func__,
+ max_hw_sectors);
}
max_hw_sectors = round_down(max_hw_sectors,
@@ -277,10 +279,12 @@ EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments);
**/
void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
{
- if (max_size < PAGE_SIZE) {
- max_size = PAGE_SIZE;
- printk(KERN_INFO "%s: set to minimum %d\n",
- __func__, max_size);
+ unsigned int min_max_segment_size = blk_queue_sub_page_segments(q) ?
+ SECTOR_SIZE : PAGE_SIZE;
+
+ if (max_size < min_max_segment_size) {
+ max_size = min_max_segment_size;
+ printk(KERN_INFO "%s: set to minimum %u\n", __func__, max_size);
}
/* see blk_queue_virt_boundary() for the explanation */
next prev parent reply other threads:[~2022-11-23 20:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-23 20:57 [PATCH v2 0/8] Add support for segments smaller than one page Bart Van Assche
2022-11-23 20:57 ` [PATCH v2 1/8] block: Introduce CONFIG_BLK_SUB_PAGE_SEGMENTS and QUEUE_FLAG_SUB_PAGE_SEGMENTS Bart Van Assche
2022-11-23 20:57 ` Bart Van Assche [this message]
2022-11-23 20:57 ` [PATCH v2 3/8] block: Support submitting passthrough requests with small segments Bart Van Assche
2022-11-23 20:57 ` [PATCH v2 4/8] block: Add support for filesystem requests and " Bart Van Assche
2022-11-23 20:57 ` [PATCH v2 5/8] block: Add support for small segments in blk_rq_map_user_iov() Bart Van Assche
2022-11-23 20:57 ` [PATCH v2 6/8] scsi: core: Set the SUB_PAGE_SEGMENTS request queue flag Bart Van Assche
2022-11-23 20:57 ` [PATCH v2 7/8] scsi_debug: Support configuring the maximum segment size Bart Van Assche
2022-11-25 17:34 ` Douglas Gilbert
2022-11-30 22:30 ` Bart Van Assche
2022-11-23 20:57 ` [PATCH v2 8/8] null_blk: " Bart Van Assche
2022-11-24 1:40 ` Damien Le Moal
2022-11-30 22:29 ` Bart Van Assche
2022-12-01 0:39 ` Damien Le Moal
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221123205740.463185-3-bvanassche@acm.org \
--to=bvanassche@acm.org \
--cc=adrian.hunter@intel.com \
--cc=avri.altman@wdc.com \
--cc=axboe@kernel.dk \
--cc=hch@lst.de \
--cc=kbusch@kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=ming.lei@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).