On Mon, Jan 13 2014 at 7:14pm -0500, Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote: > This patch modifies dm-snapshot so that it prefetches the buffers when > loading the exceptions. > > The number of buffers read ahead is specified in the DM_PREFETCH_CHUNKS > macro. > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > > --- > drivers/md/dm-snap-persistent.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > Index: linux-3.13-rc7/drivers/md/dm-snap-persistent.c > =================================================================== > --- linux-3.13-rc7.orig/drivers/md/dm-snap-persistent.c 2014-01-14 00:54:52.000000000 +0100 > +++ linux-3.13-rc7/drivers/md/dm-snap-persistent.c 2014-01-14 00:56:39.000000000 +0100 > @@ -18,6 +18,8 @@ > #define DM_MSG_PREFIX "persistent snapshot" > #define DM_CHUNK_SIZE_DEFAULT_SECTORS 32 /* 16KB */ > > +#define DM_PREFETCH_CHUNKS 12 > + > /*----------------------------------------------------------------- > * Persistent snapshots, by persistent we mean that the snapshot > * will survive a reboot. ... > @@ -504,6 +507,8 @@ static int read_exceptions(struct pstore > if (IS_ERR(client)) > return PTR_ERR(client); > > + dm_bufio_set_minimum_buffers(client, DM_PREFETCH_CHUNKS + 1); > + Why the +1? I'd prefer that be managed in dm-bufio rather than relying on all callers to know to add +1. Can you supply a followup patch that cleans this up in bufio and remove the +1 in the above dm_bufio_set_minimum_buffers call? -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
