From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells In-Reply-To: <20070413102518.GD31487@wotan.suse.de> References: <20070413102518.GD31487@wotan.suse.de> <20070413100416.GC31487@wotan.suse.de> Subject: Re: [patch] generic rwsems Date: Fri, 13 Apr 2007 12:44:50 +0100 Message-ID: <25428.1176464690@redhat.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andrew Morton , Andi Kleen , Linux Kernel Mailing List , Linux Memory Management List , Linus Torvalds List-ID: Nick Piggin wrote: > I think I should put wait_lock after wait_list, so as to get a better > packing on most 64-bit architectures. It makes no difference. struct lockdep_map contains at least one pointer and so is going to be 8-byte aligned (assuming it's there at all). struct rw_semaphore contains at least one pointer/long, so it will be padded out to 8-byte size. If you want to make a difference, you'd need to add __attribute__((packed)) but you would need to be very careful with that. David -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org