lkml.org 
[lkml]   [2012]   [Jan]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] xen-blkfront: use bitmap_set() and bitmap_clear()
    On Sat, Jan 21, 2012 at 12:15:26AM +0900, Akinobu Mita wrote:
    > Use bitmap_set and bitmap_clear rather than modifying individual bits
    > in a memory region.
    >
    > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
    > Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
    > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
    > Cc: xen-devel@lists.xensource.com
    > Cc: virtualization@lists.linux-foundation.org
    > ---
    > drivers/block/xen-blkfront.c | 7 +++----
    > 1 files changed, 3 insertions(+), 4 deletions(-)
    >
    > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
    > index 2f22874..619868d 100644
    > --- a/drivers/block/xen-blkfront.c
    > +++ b/drivers/block/xen-blkfront.c
    > @@ -43,6 +43,7 @@
    > #include <linux/slab.h>
    > #include <linux/mutex.h>
    > #include <linux/scatterlist.h>
    > +#include <linux/bitmap.h>
    >
    > #include <xen/xen.h>
    > #include <xen/xenbus.h>
    > @@ -177,8 +178,7 @@ static int xlbd_reserve_minors(unsigned int minor, unsigned int nr)
    >
    > spin_lock(&minor_lock);
    > if (find_next_bit(minors, end, minor) >= end) {
    > - for (; minor < end; ++minor)
    > - __set_bit(minor, minors);
    > + bitmap_set(minors, minor, nr);

    Hm, I would have thought the last argument should have been 'end'?

    Did you test this patch with a large amount of minors?

    > rc = 0;
    > } else
    > rc = -EBUSY;
    > @@ -193,8 +193,7 @@ static void xlbd_release_minors(unsigned int minor, unsigned int nr)
    >
    > BUG_ON(end > nr_minors);
    > spin_lock(&minor_lock);
    > - for (; minor < end; ++minor)
    > - __clear_bit(minor, minors);
    > + bitmap_clear(minors, minor, nr);

    Ditto.
    > spin_unlock(&minor_lock);
    > }
    >
    > --
    > 1.7.4.4
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at http://www.tux.org/lkml/


    \
     
     \ /
      Last update: 2012-01-20 16:33    [W:0.050 / U:30.360 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site