From: Stefan Haberland <sth@linux.ibm.com>
To: linux-s390@vger.kernel.org
Cc: Jan Hoeppner <hoeppner@linux.ibm.com>,
Eduard Shishkin <edward6@linux.ibm.com>
Subject: [PATCH v6 04/18] s390/dasd: Optimize max blocks per request for track alignment
Date: Sat, 1 Aug 2026 13:09:54 +0200 [thread overview]
Message-ID: <20260801111008.3391031-5-sth@linux.ibm.com> (raw)
In-Reply-To: <20260801111008.3391031-1-sth@linux.ibm.com>
With 4096-byte blocks a full ECKD track holds exactly 12 records. Lower
DASD_ECKD_MAX_BLOCKS from 190 to 180 so requests align to track
boundaries (15 full tracks); full-track I/O is more efficient than
partial-track writes, and 190 had no alignment significance and could
let a request cross a track boundary.
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
---
drivers/s390/block/dasd_eckd.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index f9299bd184ba..763733bcc4d2 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -131,7 +131,7 @@
/*
* Maximum number of blocks to be chained
*/
-#define DASD_ECKD_MAX_BLOCKS 190
+#define DASD_ECKD_MAX_BLOCKS 180
#define DASD_ECKD_MAX_BLOCKS_RAW 256
/*****************************************************************************
--
2.53.0
next prev parent reply other threads:[~2026-08-01 11:10 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-01 11:09 [PATCH v6 00/18] s390/dasd: ESE thin-provisioning performance improvements Stefan Haberland
2026-08-01 11:09 ` [PATCH v6 01/18] s390/dasd: Do not complete a failed ESE read as successful Stefan Haberland
2026-08-01 11:27 ` sashiko-bot
2026-08-01 11:09 ` [PATCH v6 02/18] s390/dasd: Propagate partial completion length across ERP recovery Stefan Haberland
2026-08-01 11:21 ` sashiko-bot
2026-08-01 11:09 ` [PATCH v6 03/18] s390/dasd: Guard sysfs discipline callbacks against unallocated private data Stefan Haberland
2026-08-01 11:40 ` sashiko-bot
2026-08-01 11:09 ` Stefan Haberland [this message]
2026-08-01 11:20 ` [PATCH v6 04/18] s390/dasd: Optimize max blocks per request for track alignment sashiko-bot
2026-08-01 11:09 ` [PATCH v6 05/18] s390/dasd: Use GFP_KERNEL in dasd_alloc_device() Stefan Haberland
2026-08-01 11:21 ` sashiko-bot
2026-08-01 11:09 ` [PATCH v6 06/18] s390/dasd: Add defines for the Extended Address Volume track address Stefan Haberland
2026-08-01 11:13 ` sashiko-bot
2026-08-01 11:09 ` [PATCH v6 07/18] s390/dasd: Add infrastructure for ESE full-track write Stefan Haberland
2026-08-01 11:32 ` sashiko-bot
2026-08-01 11:09 ` [PATCH v6 08/18] s390/dasd: Add range-based format-track collision detection Stefan Haberland
2026-08-01 11:36 ` sashiko-bot
2026-08-01 11:09 ` [PATCH v6 09/18] s390/dasd: Extend prepare_itcw() to support WRITE_FULL_TRACK Stefan Haberland
2026-08-01 11:37 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 10/18] s390/dasd: Add dasd_eckd_build_cp_tpm_writefulltrack() Stefan Haberland
2026-08-01 11:29 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 11/18] s390/dasd: Use WRITE_FULL_TRACK in ESE format handler Stefan Haberland
2026-08-01 11:39 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 12/18] s390/dasd: Add full_track_bias to control fulltrack write mode Stefan Haberland
2026-08-01 11:27 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 13/18] s390/dasd: Derive adaptive ESE fulltrack heuristic from ft_bias Stefan Haberland
2026-08-01 11:46 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 14/18] s390/dasd: Stamp a format label into newly formatted volumes Stefan Haberland
2026-08-01 11:33 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 15/18] s390/dasd: Detect ESE volumes from the on-disk format label Stefan Haberland
2026-08-01 11:38 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 16/18] s390/dasd: Report ESE capability and format mode at device online Stefan Haberland
2026-08-01 11:45 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 17/18] s390/dasd: Re-enable discard support for ESE volumes Stefan Haberland
2026-08-01 11:45 ` sashiko-bot
2026-08-01 11:10 ` [PATCH v6 18/18] s390/dasd: Read cached unit address and LSS in the CCW build path Stefan Haberland
2026-08-01 11:49 ` sashiko-bot
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=20260801111008.3391031-5-sth@linux.ibm.com \
--to=sth@linux.ibm.com \
--cc=edward6@linux.ibm.com \
--cc=hoeppner@linux.ibm.com \
--cc=linux-s390@vger.kernel.org \
/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