From 4793e7c5e1c88382ead18db5ca072bac54467318 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 2 Sep 2008 16:29:46 +0300 Subject: UBIFS: add bulk-read facility Some flash media are capable of reading sequentially at faster rates. UBIFS bulk-read facility is designed to take advantage of that, by reading in one go consecutive data nodes that are also located consecutively in the same LEB. Read speed on Arm platform with OneNAND goes from 17 MiB/s to 19 MiB/s. Signed-off-by: Adrian Hunter --- Documentation/filesystems/ubifs.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt index 6a0d70a22f05..340512c32506 100644 --- a/Documentation/filesystems/ubifs.txt +++ b/Documentation/filesystems/ubifs.txt @@ -86,6 +86,9 @@ norm_unmount (*) commit on unmount; the journal is committed fast_unmount do not commit on unmount; this option makes unmount faster, but the next mount slower because of the need to replay the journal. +bulk_read read more in one go to take advantage of flash + media that read faster sequentially +no_bulk_read (*) do not bulk-read Quick usage instructions -- cgit v1.2.2 From 2953e73f1ce4b3284b409aefb9d46bbde6515c37 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Thu, 4 Sep 2008 16:26:00 +0300 Subject: UBIFS: add no_chk_data_crc mount option UBIFS read performance can be improved by skipping the CRC check when data nodes are read. This option can be used if the underlying media is considered to be highly reliable. Note that CRCs are always checked for metadata. Read speed on Arm platform with OneNAND goes from 19 MiB/s to 27 MiB/s with data CRC checking disabled. Signed-off-by: Adrian Hunter --- Documentation/filesystems/ubifs.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt index 340512c32506..dd84ea3c10da 100644 --- a/Documentation/filesystems/ubifs.txt +++ b/Documentation/filesystems/ubifs.txt @@ -89,6 +89,12 @@ fast_unmount do not commit on unmount; this option makes bulk_read read more in one go to take advantage of flash media that read faster sequentially no_bulk_read (*) do not bulk-read +no_chk_data_crc skip checking of CRCs on data nodes in order to + improve read performance. Use this option only + if the flash media is highly reliable. The effect + of this option is that corruption of the contents + of a file can go unnoticed. +chk_data_crc (*) do not skip checking CRCs on data nodes Quick usage instructions -- cgit v1.2.2