The patch titled
readahead: code cleanup
has been added to the -mm tree. Its filename is
readahead-code-cleanup.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: readahead: code cleanup
From: Jan Kara <jack@xxxxxxx>
Rename file_ra_state.prev_page to prev_index and file_ra_state.offset to
prev_offset. Also update of prev_index in do_generic_mapping_read() is now
moved close to the update of prev_offset.
Signed-off-by: Jan Kara <jack@xxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: WU Fengguang <wfg@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/fs.h | 4 ++--
mm/filemap.c | 8 ++++----
mm/readahead.c | 30 +++++++++++++++---------------
3 files changed, 21 insertions(+), 21 deletions(-)
diff -puN include/linux/fs.h~readahead-code-cleanup include/linux/fs.h
--- a/include/linux/fs.h~readahead-code-cleanup
+++ a/include/linux/fs.h
@@ -696,13 +696,13 @@ struct file_ra_state {
unsigned long size;
unsigned long flags; /* ra flags RA_FLAG_xxx*/
unsigned long cache_hit; /* cache hit count*/
- unsigned long prev_page; /* Cache last read() position */
+ unsigned long prev_index; /* Cache last read() position */
unsigned long ahead_start; /* Ahead window */
unsigned long ahead_size;
unsigned long ra_pages; /* Maximum readahead window */
unsigned long mmap_hit; /* Cache hit stat for mmap accesses */
unsigned long mmap_miss; /* Cache miss stat for mmap accesses */
- unsigned int offset; /* Offset where last read() ended in a page */
+ unsigned int prev_offset; /* Offset where last read() ended in a page */
};
#define RA_FLAG_MISS 0x01 /* a cache miss occured against this file */
#define RA_FLAG_INCACHE 0x02 /* file is already in cache */
diff -puN mm/filemap.c~readahead-code-cleanup mm/filemap.c
--- a/mm/filemap.c~readahead-code-cleanup
+++ a/mm/filemap.c
@@ -878,8 +878,8 @@ void do_generic_mapping_read(struct addr
cached_page = NULL;
index = *ppos >> PAGE_CACHE_SHIFT;
next_index = index;
- prev_index = ra.prev_page;
- prev_offset = ra.offset;
+ prev_index = ra.prev_index;
+ prev_offset = ra.prev_offset;
last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
offset = *ppos & ~PAGE_CACHE_MASK;
@@ -932,7 +932,6 @@ page_ok:
*/
if (prev_index != index || offset != prev_offset)
mark_page_accessed(page);
- prev_index = index;
/*
* Ok, we have the page, and it's up-to-date, so
@@ -948,7 +947,8 @@ page_ok:
offset += ret;
index += offset >> PAGE_CACHE_SHIFT;
offset &= ~PAGE_CACHE_MASK;
- prev_offset = ra.offset = offset;
+ prev_index = index;
+ prev_offset = ra.prev_offset = offset;
page_cache_release(page);
if (ret == nr && desc->count)
diff -puN mm/readahead.c~readahead-code-cleanup mm/readahead.c
--- a/mm/readahead.c~readahead-code-cleanup
+++ a/mm/readahead.c
@@ -37,7 +37,7 @@ void
file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)
{
ra->ra_pages = mapping->backing_dev_info->ra_pages;
- ra->prev_page = -1;
+ ra->prev_index = -1;
}
EXPORT_SYMBOL_GPL(file_ra_state_init);
@@ -202,19 +202,19 @@ out:
* size: Number of pages in that read
* Together, these form the "current window".
* Together, start and size represent the `readahead window'.
- * prev_page: The page which the readahead algorithm most-recently inspected.
+ * prev_index: The page which the readahead algorithm most-recently inspected.
* It is mainly used to detect sequential file reading.
* If page_cache_readahead sees that it is again being called for
* a page which it just looked at, it can return immediately without
* making any state changes.
- * offset: Offset in the prev_page where the last read ended - used for
+ * offset: Offset in the prev_index where the last read ended - used for
* detection of sequential file reading.
* ahead_start,
* ahead_size: Together, these form the "ahead window".
* ra_pages: The externally controlled max readahead for this fd.
*
* When readahead is in the off state (size == 0), readahead is disabled.
- * In this state, prev_page is used to detect the resumption of sequential I/O.
+ * In this state, prev_index is used to detect the resumption of sequential I/O.
*
* The readahead code manages two windows - the "current" and the "ahead"
* windows. The intent is that while the application is walking the pages
@@ -417,7 +417,7 @@ static int make_ahead_window(struct addr
ra->ahead_size = get_next_ra_size(ra);
ra->ahead_start = ra->start + ra->size;
- block = force || (ra->prev_page >= ra->ahead_start);
+ block = force || (ra->prev_index >= ra->ahead_start);
ret = blockable_page_cache_readahead(mapping, filp,
ra->ahead_start, ra->ahead_size, ra, block);
@@ -469,13 +469,13 @@ page_cache_readahead(struct address_spac
* We avoid doing extra work and bogusly perturbing the readahead
* window expansion logic.
*/
- if (offset == ra->prev_page && --req_size)
+ if (offset == ra->prev_index && --req_size)
++offset;
- /* Note that prev_page == -1 if it is a first read */
- sequential = (offset == ra->prev_page + 1);
- ra->prev_page = offset;
- ra->offset = 0;
+ /* Note that prev_index == -1 if it is a first read */
+ sequential = (offset == ra->prev_index + 1);
+ ra->prev_index = offset;
+ ra->prev_offset = 0;
max = get_max_readahead(ra);
newsize = min(req_size, max);
@@ -484,7 +484,7 @@ page_cache_readahead(struct address_spac
if (newsize == 0 || (ra->flags & RA_FLAG_INCACHE))
goto out;
- ra->prev_page += newsize - 1;
+ ra->prev_index += newsize - 1;
/*
* Special case - first read at start of file. We'll assume it's
@@ -540,18 +540,18 @@ page_cache_readahead(struct address_spac
* we get called back on the first page of the ahead window which
* will allow us to submit more IO.
*/
- if (ra->prev_page >= ra->ahead_start) {
+ if (ra->prev_index >= ra->ahead_start) {
ra->start = ra->ahead_start;
ra->size = ra->ahead_size;
make_ahead_window(mapping, filp, ra, 0);
recheck:
- /* prev_page shouldn't overrun the ahead window */
- ra->prev_page = min(ra->prev_page,
+ /* prev_index shouldn't overrun the ahead window */
+ ra->prev_index = min(ra->prev_index,
ra->ahead_start + ra->ahead_size - 1);
}
out:
- return ra->prev_page + 1;
+ return ra->prev_index + 1;
}
EXPORT_SYMBOL_GPL(page_cache_readahead);
_
Patches currently in -mm which might be from jack@xxxxxxx are
readahead-improve-heuristic-detecting-sequential-reads.patch
readahead-code-cleanup.patch
make-remove_inode_dquot_ref-static.patch
udf-use-sector_t-and-loff_t-for-file-offsets.patch
udf-introduce-struct-extent_position.patch
udf-use-get_bh.patch
udf-add-assertions.patch
udf-support-files-larger-than-1g.patch
udf-fix-link-counts.patch
-
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