From 7c94ba27903c3c46c5829e96efb7c2a8ab7510e9 Mon Sep 17 00:00:00 2001 From: Andreas Gerstmayr Date: Tue, 10 Jan 2017 14:17:56 +0100 Subject: 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 Acked-by: Jeff Layton Signed-off-by: Yan, Zheng --- fs/ceph/super.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs/ceph/super.c') diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 6bd20d707bfd..a0a0b6d02f89 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -952,6 +952,14 @@ static int ceph_register_bdi(struct super_block *sb, fsc->backing_dev_info.ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE; + if (fsc->mount_options->rsize > fsc->mount_options->rasize && + fsc->mount_options->rsize >= PAGE_SIZE) + fsc->backing_dev_info.io_pages = + (fsc->mount_options->rsize + PAGE_SIZE - 1) + >> PAGE_SHIFT; + else if (fsc->mount_options->rsize == 0) + fsc->backing_dev_info.io_pages = ULONG_MAX; + err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%ld", atomic_long_inc_return(&bdi_seq)); if (!err) -- cgit