Re: splice: move balance_dirty_pages_ratelimited() outside of splice actor

[Jens Axboe <jens.axboe@oracle.com>]

On Tue, Jun 12 2007, Peter Zijlstra wrote:
> On Tue, 2007-06-12 at 13:31 +0200, Jens Axboe wrote:
> 
> > Would you prefer this change, then? I'd prefer keeping the current code,
> > unless it's absolutely critical that we call
> > balance_dirty_pages_ratelimited() for each and every page instead of eg
> > every 16 pages here.
> 
> For that we should call:
>   balance_dirty_pages_ratelimited_nr(mapping, nr);
> 
> Which is ok, for small nr.

OK, then this should be better:

diff --git a/fs/splice.c b/fs/splice.c
index 25ec9c8..ed40967 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -844,6 +883,9 @@ generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out,
 	sd.file = out;
 	ret = __splice_from_pipe(pipe, &sd, pipe_to_file);
 	if (ret > 0) {
+		unsigned long nr_pages;
+
+		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 		*ppos += ret;
 
 		/*
@@ -857,7 +899,7 @@ generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out,
 			if (err)
 				ret = err;
 		}
-		balance_dirty_pages_ratelimited(mapping);
+		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
 	}
 
 	return ret;
@@ -898,6 +940,9 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 
 	ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
 	if (ret > 0) {
+		unsigned long nr_pages;
+
+		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 		*ppos += ret;
 
 		/*
@@ -913,7 +958,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 			if (err)
 				ret = err;
 		}
-		balance_dirty_pages_ratelimited(mapping);
+		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
 	}
 
 	return ret;

-- 
Jens Axboe