Messages in this thread | | | Date | Fri, 20 Jan 2012 11:09:38 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH] xen-blkfront: use bitmap_set() and bitmap_clear() |
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On Sat, Jan 21, 2012 at 12:41:56AM +0900, Akinobu Mita wrote: > 2012/1/21 Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>: > > 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'? > > 'end' is the index of the last bit to clear. But the last argument of > bitmap_clear() is the number of bits to clear. So I think 'nr' is correct.
Ah, I see it. > > > Did you test this patch with a large amount of minors? > > Sorry I didn't do runtime test.
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