From: Peter Grayson <pgrayson@realmsys.com>
To: linux-mtd@lists.infradead.org
Subject: [PATCH] nandbase performance
Date: Fri, 23 Sep 2005 17:29:14 -0600 [thread overview]
Message-ID: <1127518154.6937.42.camel@localhost.localdomain> (raw)
[-- Attachment #1: Type: text/plain, Size: 215 bytes --]
Here is a patch against nand_base.c that improves partial page read
performance. The patch simply replaces a byte-by-byte copy in a for-loop
with a memcpy() call. Jffs2 does a lot of these partial page reads.
Pete
[-- Attachment #2: mtd-nandbase-performance.patch --]
[-- Type: text/x-patch, Size: 638 bytes --]
diff -uNr mtd/drivers/mtd/nand/nand_base.c mtd-nandbase/drivers/mtd/nand/nand_base.c
--- mtd/drivers/mtd/nand/nand_base.c 2005-09-16 15:30:32.000000000 -0600
+++ mtd-nandbase/drivers/mtd/nand/nand_base.c 2005-09-23 17:21:38.032055488 -0600
@@ -1311,8 +1311,9 @@
readdata:
/* Partial page read, transfer data into fs buffer */
if (!aligned) {
- for (j = col; j < end && read < len; j++)
- buf[read++] = data_poi[j];
+ int bytes_to_copy = min(end - col, (int)len - read);
+ memcpy(&buf[read], &data_poi[col], bytes_to_copy);
+ read += bytes_to_copy;
this->pagebuf = realpage;
} else
read += mtd->oobblock;
reply other threads:[~2005-09-23 23:29 UTC|newest]
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