Re: [PATCH 2/2] fs: generic_file_buffered_read() now uses find_get_pages_contig

Matthew Wilcox
2020-06-10T00:48:03Z

On Tue, Jun 09, 2020 at 08:10:36PM -0400, Kent Overstreet wrote:
> @@ -2275,83 +2287,93 @@ static ssize_t generic_file_buffered_read(struct kiocb *iocb,
> struct iov_iter *iter, ssize_t written)
> {
> struct file *filp = iocb->ki_filp;
> + struct file_ra_state *ra = &filp->f_ra;
> struct address_space *mapping = filp->f_mapping;
> struct inode *inode = mapping->host;
> - struct file_ra_state *ra = &filp->f_ra;
> size_t orig_count = iov_iter_count(iter);
> - pgoff_t last_index;
> - int error = 0;
> + struct page *pages[64];

That's 512 bytes which seems like a lot of stack space. Would 16 be
enough to see a significant fraction of the benefit?