diff options
| author | Wu Fengguang <fengguang.wu@intel.com> | 2011-11-18 20:14:04 -0800 |
|---|---|---|
| committer | Ziyan <jaraidaniel@gmail.com> | 2016-01-08 10:36:19 +0100 |
| commit | 7b502d63994494a984d6270c41dd50ab4930dbfc (patch) | |
| tree | 01c6832fc11f216762d6cc427e9280b963401382 /mm | |
| parent | e847aac49c7179cc54279f7624cabb2e6670318b (diff) | |
| download | kernel_samsung_tuna-7b502d63994494a984d6270c41dd50ab4930dbfc.tar.gz kernel_samsung_tuna-7b502d63994494a984d6270c41dd50ab4930dbfc.tar.bz2 kernel_samsung_tuna-7b502d63994494a984d6270c41dd50ab4930dbfc.zip | |
make default readahead size a kernel parameter
From: Nikanth Karthikesan <knikanth@suse.de>
Add new kernel parameter "readahead", which would be used instead of the
value of VM_MAX_READAHEAD. If the parameter is not specified, the default
of 128kb would be used.
Change-Id: I58540d4c3570d23befb9b9f1e27998e832eae88b
CC: Ankit Jain <radical@gmail.com>
CC: Dave Chinner <david@fromorbit.com>
CC: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: D. Andrei Măceș <dmaces@nd.edu>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/readahead.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index 867f9dd82dc..df60df9e32c 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -18,6 +18,32 @@ #include <linux/pagevec.h> #include <linux/pagemap.h> +unsigned long max_readahead_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE; + +static int __init readahead(char *str) +{ + unsigned long bytes; + + if (!str) + return -EINVAL; + bytes = memparse(str, &str); + if (*str != '\0') + return -EINVAL; + + if (bytes) { + if (bytes < PAGE_CACHE_SIZE) /* missed 'k'/'m' suffixes? */ + return -EINVAL; + if (bytes > 128 << 20) /* limit to 128MB */ + bytes = 128 << 20; + } + + max_readahead_pages = bytes / PAGE_CACHE_SIZE; + default_backing_dev_info.ra_pages = max_readahead_pages; + return 0; +} + +early_param("readahead", readahead); + /* * Initialise a struct file's readahead state. Assumes that the caller has * memset *ra to zero. |