Re: potential for buffer_head shrinkage.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Dec 29, 2006 at 09:45:54PM -0500, Dave Jones wrote:
 > Looking at struct buffer_head, it seems that b_state
 > uses at most 15 bits, where it's defined as a 64bit entity
 > due to it being used by bit_spin_lock and friends.
 > 
 > Given it's not uncommon for a few hundred thousand of these
 > to be present, I wonder if it's worth the effort of folding
 > b_count into the upper bits of b_state, thus shrinking
 > buffer_head by 16 bits?  This would still leave 32 bits
 > 'wasted' for further bh_state_bits expansion if necessary.

My math here based on a 64 bit compile btw in case that wasn't obvious.
32 bit wouldn't leave room for expansion.

		Dave

-- 
http://www.codemonkey.org.uk
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux