}
EXPORT_SYMBOL(default_unplug_io_fn);
-/*
- * Convienent macros for min/max read-ahead pages.
- * Note that MAX_RA_PAGES is rounded down, while MIN_RA_PAGES is rounded up.
- * The latter is necessary for systems with large page size(i.e. 64k).
- */
-#define MAX_RA_PAGES (VM_MAX_READAHEAD*1024 / PAGE_CACHE_SIZE)
-#define MIN_RA_PAGES DIV_ROUND_UP(VM_MIN_READAHEAD*1024, PAGE_CACHE_SIZE)
-
struct backing_dev_info default_backing_dev_info = {
- .ra_pages = MAX_RA_PAGES,
+ .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE,
.state = 0,
.capabilities = BDI_CAP_MAP_COPY,
.unplug_io_fn = default_unplug_io_fn,
int (*filler)(void *, struct page *), void *data)
{
struct page *page;
- struct pagevec lru_pvec;
int ret = 0;
- pagevec_init(&lru_pvec, 0);
-
while (!list_empty(pages)) {
page = list_to_page(pages);
list_del(&page->lru);
- if (add_to_page_cache(page, mapping, page->index, GFP_KERNEL)) {
+ if (add_to_page_cache_lru(page, mapping,
+ page->index, GFP_KERNEL)) {
page_cache_release(page);
continue;
}
+ page_cache_release(page);
+
ret = filler(data, page);
- if (!pagevec_add(&lru_pvec, page))
- __pagevec_lru_add(&lru_pvec);
- if (ret) {
+ if (unlikely(ret)) {
put_pages_list(pages);
break;
}
task_io_account_read(PAGE_CACHE_SIZE);
}
- pagevec_lru_add(&lru_pvec);
return ret;
}
struct list_head *pages, unsigned nr_pages)
{
unsigned page_idx;
- struct pagevec lru_pvec;
int ret;
if (mapping->a_ops->readpages) {
goto out;
}
- pagevec_init(&lru_pvec, 0);
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
struct page *page = list_to_page(pages);
list_del(&page->lru);
- if (!add_to_page_cache(page, mapping,
+ if (!add_to_page_cache_lru(page, mapping,
page->index, GFP_KERNEL)) {
mapping->a_ops->readpage(filp, page);
- if (!pagevec_add(&lru_pvec, page))
- __pagevec_lru_add(&lru_pvec);
- } else
- page_cache_release(page);
+ }
+ page_cache_release(page);
}
- pagevec_lru_add(&lru_pvec);
ret = 0;
out:
return ret;
/*
* Preallocate as many pages as we will need.
*/
- read_lock_irq(&mapping->tree_lock);
for (page_idx = 0; page_idx < nr_to_read; page_idx++) {
pgoff_t page_offset = offset + page_idx;
if (page_offset > end_index)
break;
+ rcu_read_lock();
page = radix_tree_lookup(&mapping->page_tree, page_offset);
+ rcu_read_unlock();
if (page)
continue;
- read_unlock_irq(&mapping->tree_lock);
page = page_cache_alloc_cold(mapping);
- read_lock_irq(&mapping->tree_lock);
if (!page)
break;
page->index = page_offset;
SetPageReadahead(page);
ret++;
}
- read_unlock_irq(&mapping->tree_lock);
/*
* Now start the IO. We ignore I/O errors - if the page is not
+ node_page_state(numa_node_id(), NR_FREE_PAGES)) / 2);
}
+static int __init readahead_init(void)
+{
+ int err;
+
+ err = bdi_init(&default_backing_dev_info);
+ if (!err)
+ bdi_register(&default_backing_dev_info, NULL, "default");
+
+ return err;
+}
+subsys_initcall(readahead_init);
+
/*
* Submit IO for the read-ahead request in file_ra_state.
*/
offset, req_size, 0);
}
+ /*
+ * Hit a marked page without valid readahead state.
+ * E.g. interleaved reads.
+ * Query the pagecache for async_size, which normally equals to
+ * readahead size. Ramp it up and use it as the new readahead size.
+ */
+ if (hit_readahead_marker) {
+ pgoff_t start;
+
+ read_lock_irq(&mapping->tree_lock);
+ start = radix_tree_next_hole(&mapping->page_tree, offset, max+1);
+ read_unlock_irq(&mapping->tree_lock);
+
+ if (!start || start - offset > max)
+ return 0;
+
+ ra->start = start;
+ ra->size = start - offset; /* old async_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
ra->size = get_init_ra_size(req_size, max);
ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size;
- /*
- * Hit on a marked page without valid readahead state.
- * E.g. interleaved reads.
- * Not knowing its readahead pos/size, bet on the minimal possible one.
- */
- if (hit_readahead_marker) {
- ra->start++;
- ra->size = get_next_ra_size(ra, max);
- }
-
readit:
return ra_submit(ra, mapping, filp);
}
* pagecache pages
*
* page_cache_async_ondemand() should be called when a page is used which
- * has the PG_readahead flag: this is a marker to suggest that the application
+ * has the PG_readahead flag; this is a marker to suggest that the application
* has used up enough of the readahead window that we should start pulling in
- * more pages. */
+ * more pages.
+ */
void
page_cache_async_readahead(struct address_space *mapping,
struct file_ra_state *ra, struct file *filp,
git.openpandora.org / pandora-kernel.git / blobdiff