On Wednesday, July 10, 2013 02:33:04 PM Stephen Smalley wrote: > On 06/05/2013 05:15 PM, Waiman Long wrote: > > Currently, the ebitmap_node structure has a fixed size of 32 bytes. On > > a 32-bit system, the overhead is 8 bytes, leaving 24 bytes for being > > used as bitmaps. The overhead ratio is 1/4. > > > > On a 64-bit system, the overhead is 16 bytes. Therefore, only 16 bytes > > are left for bitmap purpose and the overhead ratio is 1/2. With a > > 3.8.2 kernel, a boot-up operation will cause the ebitmap_get_bit() > > function to be called about 9 million times. The average number of > > ebitmap_node traversal is about 3.7. > > > > This patch increases the size of the ebitmap_node structure to 64 > > bytes for 64-bit system to keep the overhead ratio at 1/4. This may > > also improve performance a little bit by making node to node traversal > > less frequent (< 2) as more bits are available in each node. > > > > Signed-off-by: Waiman Long <Waiman.Long@xxxxxx> > > Acked-by: Stephen Smalley <sds@xxxxxxxxxxxxx> Looks good to me too. Merged, built, and tested okay too. * git://git.infradead.org/users/pcmoore/lblnet-2.6_next > > --- > > > > security/selinux/ss/ebitmap.h | 8 +++++++- > > 1 files changed, 7 insertions(+), 1 deletions(-) > > > > diff --git a/security/selinux/ss/ebitmap.h b/security/selinux/ss/ebitmap.h > > index e7eb3a9..712c8a7 100644 > > --- a/security/selinux/ss/ebitmap.h > > +++ b/security/selinux/ss/ebitmap.h > > @@ -16,7 +16,13 @@ > > > > #include <net/netlabel.h> > > > > -#define EBITMAP_UNIT_NUMS ((32 - sizeof(void *) - sizeof(u32)) \ > > +#ifdef CONFIG_64BIT > > +#define EBITMAP_NODE_SIZE 64 > > +#else > > +#define EBITMAP_NODE_SIZE 32 > > +#endif > > + > > +#define EBITMAP_UNIT_NUMS ((EBITMAP_NODE_SIZE-sizeof(void > > *)-sizeof(u32))\ > > > > / sizeof(unsigned long)) > > > > #define EBITMAP_UNIT_SIZE BITS_PER_LONG > > #define EBITMAP_SIZE (EBITMAP_UNIT_NUMS * EBITMAP_UNIT_SIZE) > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-security-module" in the body of a message to > majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- paul moore www.paul-moore.com -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with the words "unsubscribe selinux" without quotes as the message.
