ceph: set io_pages bdi hint

This patch sets the io_pages bdi hint based on the rsize mount option.
Without this patch large buffered reads (request size > max readahead)
are processed sequentially in chunks of the readahead size (i.e. read
requests are sent out up to the readahead size, then the
do_generic_file_read() function waits until the first page is received).

With this patch read requests are sent out at once up to the size
specified in the rsize mount option (default: 64 MB).

Signed-off-by: Andreas Gerstmayr <andreas.gerstmayr@catalysts.cc>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Yan, Zheng <zyan@redhat.com>
This commit is contained in:
Andreas Gerstmayr
2017-01-10 14:17:56 +01:00
committed by Ilya Dryomov
parent 0fbc5360bf
commit 7c94ba2790
3 changed files with 12 additions and 5 deletions

View File

@@ -98,11 +98,10 @@ Mount Options
size.
rsize=X
Specify the maximum read size in bytes. By default there is no
maximum.
Specify the maximum read size in bytes. Default: 64 MB.
rasize=X
Specify the maximum readahead.
Specify the maximum readahead. Default: 8 MB.
mount_timeout=X
Specify the timeout value for mount (in seconds), in the case