From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Date: Tue, 29 Sep 2009 18:07:40 +0000 Subject: RE: [git pull] ia64 changes Message-Id: List-Id: References: <1FE6DD409037234FAB833C420AA843EC0122AEB1@orsmsx424.amr.corp.intel.com> In-Reply-To: <1FE6DD409037234FAB833C420AA843EC0122AEB1@orsmsx424.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Tue, 29 Sep 2009, Luck, Tony wrote: > > What will be the big areas of growth? dentry? inode? Something off > in networking? I'd pick dentry, but I'm biased (I happen to think the dcache is one of the most important data structures we have). Right now, in x86-64, we lay out the spinlock along with the other int-sized things, and we've tried to pack things over the years (ie put the commonly accessed ones together). See for example commit c2452f32786159ed85f0e4b21fec09258f822fc8. I do agree that none of the static spinlocks care about size, obviously. The only time the size of a spinlock matters is when it's embedded in one of the critical common data structures. And in _many_ cases you'll have pointers there that end up forcing it to 64-bit, but 'struct dentry' is an example of something where things can be (and are) more densely packed, and people have spent some time on it. Linus