Kingsley Cheung wrote:
>
>...
> So then something of the following without the check is more
> appropriate or a starting point then?
>
Looks good to me. Here's a 2.5 version...
include/linux/mm.h | 1 +
mm/filemap.c | 12 +-----------
mm/madvise.c | 23 +++++------------------
mm/readahead.c | 13 +++++++++++++
4 files changed, 20 insertions(+), 29 deletions(-)
--- 25/mm/filemap.c~max_sane_readahead Mon Dec 9 23:44:47 2002
+++ 25-akpm/mm/filemap.c Mon Dec 9 23:47:14 2002
@@ -898,20 +898,10 @@ static ssize_t
do_readahead(struct address_space *mapping, struct file *filp,
unsigned long index, unsigned long nr)
{
- unsigned long max;
- unsigned long active;
- unsigned long inactive;
-
if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
return -EINVAL;
- /* Limit it to a sane percentage of the inactive list.. */
- get_zone_counts(&active, &inactive);
- max = inactive / 2;
- if (nr > max)
- nr = max;
-
- do_page_cache_readahead(mapping, filp, index, nr);
+ do_page_cache_readahead(mapping, filp, index, max_sane_readahead(nr));
return 0;
}
--- 25/mm/readahead.c~max_sane_readahead Mon Dec 9 23:44:55 2002
+++ 25-akpm/mm/readahead.c Mon Dec 9 23:48:39 2002
@@ -465,3 +465,16 @@ void handle_ra_miss(struct address_space
ra->next_size = min;
}
}
+
+/*
+ * Given a desired number of PAGE_CACHE_SIZE readahead pages, return a
+ * sensible upper limit.
+ */
+unsigned long max_sane_readahead(unsigned long nr)
+{
+ unsigned long active;
+ unsigned long inactive;
+
+ get_zone_counts(&active, &inactive);
+ return min(nr, inactive / 2);
+}
--- 25/include/linux/mm.h~max_sane_readahead Mon Dec 9 23:47:45 2002
+++ 25-akpm/include/linux/mm.h Mon Dec 9 23:48:06 2002
@@ -524,6 +524,7 @@ void page_cache_readaround(struct addres
unsigned long offset);
void handle_ra_miss(struct address_space *mapping,
struct file_ra_state *ra);
+unsigned long max_sane_readahead(unsigned long nr);
/* Do stack extension */
extern int expand_stack(struct vm_area_struct * vma, unsigned long address);
--- 25/mm/madvise.c~max_sane_readahead Mon Dec 9 23:52:37 2002
+++ 25-akpm/mm/madvise.c Mon Dec 9 23:52:41 2002
@@ -51,36 +51,23 @@ static long madvise_behavior(struct vm_a
}
/*
- * Schedule all required I/O operations, then run the disk queue
- * to make sure they are started. Do not wait for completion.
+ * Schedule all required I/O operations. Do not wait for completion.
*/
static long madvise_willneed(struct vm_area_struct * vma,
unsigned long start, unsigned long end)
{
- long error = -EBADF;
- struct file * file;
- unsigned long size, rlim_rss;
+ struct file *file = vma->vm_file;
- /* Doesn't work if there's no mapped file. */
if (!vma->vm_file)
- return error;
- file = vma->vm_file;
- size = (file->f_dentry->d_inode->i_size + PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
+ return -EBADF;
start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
if (end > vma->vm_end)
end = vma->vm_end;
end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
- /* Make sure this doesn't exceed the process's max rss. */
- error = -EIO;
- rlim_rss = current->rlim ? current->rlim[RLIMIT_RSS].rlim_cur :
- LONG_MAX; /* default: see resource.h */
- if ((vma->vm_mm->rss + (end - start)) > rlim_rss)
- return error;
-
- do_page_cache_readahead(file->f_dentry->d_inode->i_mapping, file, start, end - start);
+ do_page_cache_readahead(file->f_dentry->d_inode->i_mapping,
+ file, start, max_sane_readahead(end - start));
return 0;
}
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Dec 15 2002 - 22:00:17 EST