scst: Remove old kernel readahead patches

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@8021 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Bart Van Assche
2019-03-09 23:09:58 +00:00
parent 1b23ac9120
commit 24a5d97db9
11 changed files with 0 additions and 574 deletions

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@@ -1,13 +0,0 @@
diff --git a/mm/readahead.c b/mm/readahead.c
index 133b6d5..fd3df66 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -473,5 +473,8 @@ page_cache_async_readahead(struct address_space *mapping,
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

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@@ -1,13 +0,0 @@
diff --git a/mm/readahead.c b/mm/readahead.c
index 133b6d5..fd3df66 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -479,5 +479,8 @@ page_cache_async_readahead(struct address_space *mapping,
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

View File

@@ -1,13 +0,0 @@
diff --git a/mm/readahead.c b/mm/readahead.c
index 133b6d5..fd3df66 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -479,5 +479,8 @@ page_cache_async_readahead(struct address_space *mapping,
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

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@@ -1,13 +0,0 @@
diff --git a/mm/readahead.c b/mm/readahead.c
index 133b6d5..fd3df66 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -479,5 +479,8 @@ page_cache_async_readahead(struct address_space *mapping,
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

View File

@@ -1,13 +0,0 @@
diff --git a/mm/readahead.c b/mm/readahead.c
index 133b6d5..fd3df66 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -479,5 +479,8 @@ page_cache_async_readahead(struct address_space *mapping,
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

View File

@@ -1,12 +0,0 @@
diff -upkr linux-2.6.30.1/mm/readahead.c linux-2.6.30.1/mm/readahead.c
--- linux-2.6.30.1/mm/readahead.c 2009-07-01 13:52:31.000000000 +0400
+++ linux-2.6.30.1/mm/readahead.c 2009-07-01 15:55:08.000000000 +0400
@@ -565,5 +565,8 @@ page_cache_async_readahead(struct addres
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

View File

@@ -1,12 +0,0 @@
diff -upkr linux-2.6.31/mm/readahead.c linux-2.6.31/mm/readahead.c
--- linux-2.6.31/mm/readahead.c 2009-09-10 02:13:59.000000000 +0400
+++ linux-2.6.31/mm/readahead.c 2009-09-23 14:17:26.000000000 +0400
@@ -547,5 +547,8 @@ page_cache_async_readahead(struct addres
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

View File

@@ -1,12 +0,0 @@
diff -upkr linux-2.6.32.1/mm/readahead.c linux-2.6.32.1/mm/readahead.c
--- linux-2.6.32.1/mm/readahead.c 2009-12-03 06:51:21.000000000 +0300
+++ linux-2.6.32.1/mm/readahead.c 2009-12-16 15:21:00.000000000 +0300
@@ -547,5 +547,8 @@ page_cache_async_readahead(struct addres
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);

View File

@@ -1,231 +0,0 @@
--- linux.orig/mm/readahead.c
+++ linux/mm/readahead.c
@@ -337,6 +337,59 @@ static unsigned long get_next_ra_size(st
*/
/*
+ * Count contiguously cached pages from @offset-1 to @offset-@max,
+ * this count is a conservative estimation of
+ * - length of the sequential read sequence, or
+ * - thrashing threshold in memory tight systems
+ */
+static pgoff_t count_history_pages(struct address_space *mapping,
+ struct file_ra_state *ra,
+ pgoff_t offset, unsigned long max)
+{
+ pgoff_t head;
+
+ rcu_read_lock();
+ head = radix_tree_prev_hole(&mapping->page_tree, offset - 1, max);
+ rcu_read_unlock();
+
+ return offset - 1 - head;
+}
+
+/*
+ * page cache context based read-ahead
+ */
+static int try_context_readahead(struct address_space *mapping,
+ struct file_ra_state *ra,
+ pgoff_t offset,
+ unsigned long req_size,
+ unsigned long max)
+{
+ pgoff_t size;
+
+ size = count_history_pages(mapping, ra, offset, max);
+
+ /*
+ * no history pages:
+ * it could be a random read
+ */
+ if (!size)
+ return 0;
+
+ /*
+ * starts from beginning of file:
+ * it is a strong indication of long-run stream (or whole-file-read)
+ */
+ if (size >= offset)
+ size *= 2;
+
+ ra->start = offset;
+ ra->size = get_init_ra_size(size + req_size, max);
+ ra->async_size = ra->size;
+
+ return 1;
+}
+
+/*
* A minimal readahead algorithm for trivial sequential/random reads.
*/
static unsigned long
@@ -345,34 +398,26 @@ ondemand_readahead(struct address_space
bool hit_readahead_marker, pgoff_t offset,
unsigned long req_size)
{
- int max = ra->ra_pages; /* max readahead pages */
- pgoff_t prev_offset;
- int sequential;
+ unsigned long max = max_sane_readahead(ra->ra_pages);
+
+ /*
+ * start of file
+ */
+ if (!offset)
+ goto initial_readahead;
/*
* It's the expected callback offset, assume sequential access.
* Ramp up sizes, and push forward the readahead window.
*/
- if (offset && (offset == (ra->start + ra->size - ra->async_size) ||
- offset == (ra->start + ra->size))) {
+ if ((offset == (ra->start + ra->size - ra->async_size) ||
+ offset == (ra->start + ra->size))) {
ra->start += ra->size;
ra->size = get_next_ra_size(ra, max);
ra->async_size = ra->size;
goto readit;
}
- prev_offset = ra->prev_pos >> PAGE_CACHE_SHIFT;
- sequential = offset - prev_offset <= 1UL || req_size > max;
-
- /*
- * Standalone, small read.
- * Read as is, and do not pollute the readahead state.
- */
- if (!hit_readahead_marker && !sequential) {
- return __do_page_cache_readahead(mapping, filp,
- offset, req_size, 0);
- }
-
/*
* Hit a marked page without valid readahead state.
* E.g. interleaved reads.
@@ -383,7 +428,7 @@ ondemand_readahead(struct address_space
pgoff_t start;
rcu_read_lock();
- start = radix_tree_next_hole(&mapping->page_tree, offset,max+1);
+ start = radix_tree_next_hole(&mapping->page_tree, offset+1, max);
rcu_read_unlock();
if (!start || start - offset > max)
@@ -391,23 +436,53 @@ ondemand_readahead(struct address_space
ra->start = start;
ra->size = start - offset; /* old async_size */
+ ra->size += req_size;
ra->size = get_next_ra_size(ra, max);
ra->async_size = ra->size;
goto readit;
}
/*
- * It may be one of
- * - first read on start of file
- * - sequential cache miss
- * - oversize random read
- * Start readahead for it.
+ * oversize read
+ */
+ if (req_size > max)
+ goto initial_readahead;
+
+ /*
+ * sequential cache miss
*/
+ if (offset - (ra->prev_pos >> PAGE_CACHE_SHIFT) <= 1UL)
+ goto initial_readahead;
+
+ /*
+ * Query the page cache and look for the traces(cached history pages)
+ * that a sequential stream would leave behind.
+ */
+ if (try_context_readahead(mapping, ra, offset, req_size, max))
+ goto readit;
+
+ /*
+ * standalone, small random read
+ * Read as is, and do not pollute the readahead state.
+ */
+ return __do_page_cache_readahead(mapping, filp, offset, req_size, 0);
+
+initial_readahead:
ra->start = offset;
ra->size = get_init_ra_size(req_size, max);
ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size;
readit:
+ /*
+ * Will this read hit the readahead marker made by itself?
+ * If so, trigger the readahead marker hit now, and merge
+ * the resulted next readahead window into the current one.
+ */
+ if (offset == ra->start && ra->size == ra->async_size) {
+ ra->async_size = get_next_ra_size(ra, max);
+ ra->size += ra->async_size;
+ }
+
return ra_submit(ra, mapping, filp);
}
--- linux.orig/lib/radix-tree.c
+++ linux/lib/radix-tree.c
@@ -666,6 +666,43 @@ unsigned long radix_tree_next_hole(struc
}
EXPORT_SYMBOL(radix_tree_next_hole);
+/**
+ * radix_tree_prev_hole - find the prev hole (not-present entry)
+ * @root: tree root
+ * @index: index key
+ * @max_scan: maximum range to search
+ *
+ * Search backwards in the range [max(index-max_scan+1, 0), index]
+ * for the first hole.
+ *
+ * Returns: the index of the hole if found, otherwise returns an index
+ * outside of the set specified (in which case 'index - return >= max_scan'
+ * will be true). In rare cases of wrap-around, LONG_MAX will be returned.
+ *
+ * radix_tree_next_hole may be called under rcu_read_lock. However, like
+ * radix_tree_gang_lookup, this will not atomically search a snapshot of
+ * the tree at a single point in time. For example, if a hole is created
+ * at index 10, then subsequently a hole is created at index 5,
+ * radix_tree_prev_hole covering both indexes may return 5 if called under
+ * rcu_read_lock.
+ */
+unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan)
+{
+ unsigned long i;
+
+ for (i = 0; i < max_scan; i++) {
+ if (!radix_tree_lookup(root, index))
+ break;
+ index--;
+ if (index == LONG_MAX)
+ break;
+ }
+
+ return index;
+}
+EXPORT_SYMBOL(radix_tree_prev_hole);
+
static unsigned int
__lookup(struct radix_tree_node *slot, void ***results, unsigned long index,
unsigned int max_items, unsigned long *next_index)
--- linux.orig/include/linux/radix-tree.h
+++ linux/include/linux/radix-tree.h
@@ -167,6 +167,8 @@ radix_tree_gang_lookup_slot(struct radix
unsigned long first_index, unsigned int max_items);
unsigned long radix_tree_next_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
+unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan);
int radix_tree_preload(gfp_t gfp_mask);
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *root,

View File

@@ -1,231 +0,0 @@
--- linux.orig/mm/readahead.c
+++ linux/mm/readahead.c
@@ -348,6 +348,59 @@ static unsigned long get_next_ra_size(st
*/
/*
+ * Count contiguously cached pages from @offset-1 to @offset-@max,
+ * this count is a conservative estimation of
+ * - length of the sequential read sequence, or
+ * - thrashing threshold in memory tight systems
+ */
+static pgoff_t count_history_pages(struct address_space *mapping,
+ struct file_ra_state *ra,
+ pgoff_t offset, unsigned long max)
+{
+ pgoff_t head;
+
+ rcu_read_lock();
+ head = radix_tree_prev_hole(&mapping->page_tree, offset - 1, max);
+ rcu_read_unlock();
+
+ return offset - 1 - head;
+}
+
+/*
+ * page cache context based read-ahead
+ */
+static int try_context_readahead(struct address_space *mapping,
+ struct file_ra_state *ra,
+ pgoff_t offset,
+ unsigned long req_size,
+ unsigned long max)
+{
+ pgoff_t size;
+
+ size = count_history_pages(mapping, ra, offset, max);
+
+ /*
+ * no history pages:
+ * it could be a random read
+ */
+ if (!size)
+ return 0;
+
+ /*
+ * starts from beginning of file:
+ * it is a strong indication of long-run stream (or whole-file-read)
+ */
+ if (size >= offset)
+ size *= 2;
+
+ ra->start = offset;
+ ra->size = get_init_ra_size(size + req_size, max);
+ ra->async_size = ra->size;
+
+ return 1;
+}
+
+/*
* A minimal readahead algorithm for trivial sequential/random reads.
*/
static unsigned long
@@ -356,34 +409,26 @@ ondemand_readahead(struct address_space
bool hit_readahead_marker, pgoff_t offset,
unsigned long req_size)
{
- int max = ra->ra_pages; /* max readahead pages */
- pgoff_t prev_offset;
- int sequential;
+ unsigned long max = max_sane_readahead(ra->ra_pages);
+
+ /*
+ * start of file
+ */
+ if (!offset)
+ goto initial_readahead;
/*
* It's the expected callback offset, assume sequential access.
* Ramp up sizes, and push forward the readahead window.
*/
- if (offset && (offset == (ra->start + ra->size - ra->async_size) ||
- offset == (ra->start + ra->size))) {
+ if ((offset == (ra->start + ra->size - ra->async_size) ||
+ offset == (ra->start + ra->size))) {
ra->start += ra->size;
ra->size = get_next_ra_size(ra, max);
ra->async_size = ra->size;
goto readit;
}
- prev_offset = ra->prev_pos >> PAGE_CACHE_SHIFT;
- sequential = offset - prev_offset <= 1UL || req_size > max;
-
- /*
- * Standalone, small read.
- * Read as is, and do not pollute the readahead state.
- */
- if (!hit_readahead_marker && !sequential) {
- return __do_page_cache_readahead(mapping, filp,
- offset, req_size, 0);
- }
-
/*
* Hit a marked page without valid readahead state.
* E.g. interleaved reads.
@@ -394,7 +439,7 @@ ondemand_readahead(struct address_space
pgoff_t start;
rcu_read_lock();
- start = radix_tree_next_hole(&mapping->page_tree, offset,max+1);
+ start = radix_tree_next_hole(&mapping->page_tree, offset+1, max);
rcu_read_unlock();
if (!start || start - offset > max)
@@ -402,23 +447,53 @@ ondemand_readahead(struct address_space
ra->start = start;
ra->size = start - offset; /* old async_size */
+ ra->size += req_size;
ra->size = get_next_ra_size(ra, max);
ra->async_size = ra->size;
goto readit;
}
/*
- * It may be one of
- * - first read on start of file
- * - sequential cache miss
- * - oversize random read
- * Start readahead for it.
+ * oversize read
+ */
+ if (req_size > max)
+ goto initial_readahead;
+
+ /*
+ * sequential cache miss
*/
+ if (offset - (ra->prev_pos >> PAGE_CACHE_SHIFT) <= 1UL)
+ goto initial_readahead;
+
+ /*
+ * Query the page cache and look for the traces(cached history pages)
+ * that a sequential stream would leave behind.
+ */
+ if (try_context_readahead(mapping, ra, offset, req_size, max))
+ goto readit;
+
+ /*
+ * standalone, small random read
+ * Read as is, and do not pollute the readahead state.
+ */
+ return __do_page_cache_readahead(mapping, filp, offset, req_size, 0);
+
+initial_readahead:
ra->start = offset;
ra->size = get_init_ra_size(req_size, max);
ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size;
readit:
+ /*
+ * Will this read hit the readahead marker made by itself?
+ * If so, trigger the readahead marker hit now, and merge
+ * the resulted next readahead window into the current one.
+ */
+ if (offset == ra->start && ra->size == ra->async_size) {
+ ra->async_size = get_next_ra_size(ra, max);
+ ra->size += ra->async_size;
+ }
+
return ra_submit(ra, mapping, filp);
}
--- linux.orig/lib/radix-tree.c
+++ linux/lib/radix-tree.c
@@ -666,6 +666,43 @@ unsigned long radix_tree_next_hole(struc
}
EXPORT_SYMBOL(radix_tree_next_hole);
+/**
+ * radix_tree_prev_hole - find the prev hole (not-present entry)
+ * @root: tree root
+ * @index: index key
+ * @max_scan: maximum range to search
+ *
+ * Search backwards in the range [max(index-max_scan+1, 0), index]
+ * for the first hole.
+ *
+ * Returns: the index of the hole if found, otherwise returns an index
+ * outside of the set specified (in which case 'index - return >= max_scan'
+ * will be true). In rare cases of wrap-around, LONG_MAX will be returned.
+ *
+ * radix_tree_next_hole may be called under rcu_read_lock. However, like
+ * radix_tree_gang_lookup, this will not atomically search a snapshot of
+ * the tree at a single point in time. For example, if a hole is created
+ * at index 10, then subsequently a hole is created at index 5,
+ * radix_tree_prev_hole covering both indexes may return 5 if called under
+ * rcu_read_lock.
+ */
+unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan)
+{
+ unsigned long i;
+
+ for (i = 0; i < max_scan; i++) {
+ if (!radix_tree_lookup(root, index))
+ break;
+ index--;
+ if (index == LONG_MAX)
+ break;
+ }
+
+ return index;
+}
+EXPORT_SYMBOL(radix_tree_prev_hole);
+
static unsigned int
__lookup(struct radix_tree_node *slot, void ***results, unsigned long index,
unsigned int max_items, unsigned long *next_index)
--- linux.orig/include/linux/radix-tree.h
+++ linux/include/linux/radix-tree.h
@@ -167,6 +167,8 @@ radix_tree_gang_lookup_slot(struct radix
unsigned long first_index, unsigned int max_items);
unsigned long radix_tree_next_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
+unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan);
int radix_tree_preload(gfp_t gfp_mask);
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *root,

View File

@@ -1,11 +0,0 @@
--- linux-2.6.24-24.53/mm/readahead.c 2008-02-11 06:51:11.000000000 +0100
+++ linux-2.6.24-24.53.copy/mm/readahead.c 2009-06-09 21:59:13.640647726 +0200
@@ -472,5 +472,8 @@ page_cache_async_readahead(struct addres
/* do read-ahead */
ondemand_readahead(mapping, ra, filp, true, offset, req_size);
+
+ if (PageUptodate(page))
+ blk_run_backing_dev(mapping->backing_dev_info, NULL);
}
EXPORT_SYMBOL_GPL(page_cache_async_readahead);