> On 10 Jan 2017, at 21:17, Andreas Gerstmayr <andreas.gerstmayr@xxxxxxxxxxxx> wrote: > > 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@xxxxxxxxxxxx> > --- > > Changes in v4: > - update documentation > > (Note: This patch depends on kernel version 4.10-rc1) > > > Documentation/filesystems/ceph.txt | 5 ++--- > fs/ceph/super.c | 8 ++++++++ > fs/ceph/super.h | 4 ++-- > 3 files changed, 12 insertions(+), 5 deletions(-) > > diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt > index f5306ee..0b302a1 100644 > --- a/Documentation/filesystems/ceph.txt > +++ b/Documentation/filesystems/ceph.txt > @@ -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 > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index 6bd20d7..a0a0b6d 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) > diff --git a/fs/ceph/super.h b/fs/ceph/super.h > index 3373b61..88b2e6e 100644 > --- a/fs/ceph/super.h > +++ b/fs/ceph/super.h > @@ -45,8 +45,8 @@ > #define ceph_test_mount_opt(fsc, opt) \ > (!!((fsc)->mount_options->flags & CEPH_MOUNT_OPT_##opt)) > > -#define CEPH_RSIZE_DEFAULT 0 /* max read size */ > -#define CEPH_RASIZE_DEFAULT (8192*1024) /* readahead */ > +#define CEPH_RSIZE_DEFAULT (64*1024*1024) /* max read size */ > +#define CEPH_RASIZE_DEFAULT (8192*1024) /* max readahead */ > #define CEPH_MAX_READDIR_DEFAULT 1024 > #define CEPH_MAX_READDIR_BYTES_DEFAULT (512*1024) > #define CEPH_SNAPDIRNAME_DEFAULT ".snap” Applied, Thanks Yan, Zheng > -- > 1.8.3.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
