From: Richard Kennedy <richard@rsk.demon.co.uk>
To: jgarzik <jgarzik@pobox.com>
Cc: Tejun Heo <tj@kernel.org>, lkml <linux-kernel@vger.kernel.org>,
linux-ide@vger.kernel.org
Subject: [PATCH] libata: reorder ata_queued_cmd to remove alignment padding on 64 bit builds
Date: Fri, 10 Sep 2010 12:19:43 +0100 [thread overview]
Message-ID: <1284117583.1903.8.camel@castor.rsk> (raw)
Reorder structure ata_queued_cmd to remove 8 bytes of alignment padding
on 64 bit builds & therefore reduce the size of structure ata_port by
256 bytes.
Overall this will have little impact, other than reducing the amount of
memory that is cleared when allocating ata_ports.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against 2.6.36-rc3
compiled & tested on x86_64
I've been running this patch for a couple of weeks with no apparent
issues.
regards
Richard
diff --git a/include/linux/libata.h b/include/linux/libata.h
index f010f18..e115380 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -559,13 +559,13 @@ struct ata_queued_cmd {
unsigned int extrabytes;
unsigned int curbytes;
- struct scatterlist *cursg;
- unsigned int cursg_ofs;
-
struct scatterlist sgent;
struct scatterlist *sg;
+ struct scatterlist *cursg;
+ unsigned int cursg_ofs;
+
unsigned int err_mask;
struct ata_taskfile result_tf;
ata_qc_cb_t complete_fn;
next reply other threads:[~2010-09-10 11:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-10 11:19 Richard Kennedy [this message]
[not found] ` <4C8A3F1E.8050400@gmail.com>
2010-09-12 11:21 ` Richard Kennedy
2010-09-17 6:13 ` Jeff Garzik
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