From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id m8OCWTH6031138 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 24 Sep 2008 21:32:29 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 3A517240047 for ; Wed, 24 Sep 2008 21:32:29 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 119582DC12F for ; Wed, 24 Sep 2008 21:32:29 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 2DD181DB803F for ; Wed, 24 Sep 2008 21:32:25 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id CB2AA1DB803B for ; Wed, 24 Sep 2008 21:32:24 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 1/2] Report the pagesize backing a VMA in /proc/pid/smaps In-Reply-To: <20080923194655.GA25542@csn.ul.ie> References: <20080923211140.DC16.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080923194655.GA25542@csn.ul.ie> Message-Id: <20080924210309.8C3B.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 24 Sep 2008 21:32:24 +0900 (JST) Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Dave Hansen , LKML , Linux-MM List-ID: > > Dave, please let me know getpagesize() function return to 4k or 64k on ppc64. > > I think the PageSize line of the /proc/pid/smap and getpagesize() result should be matched. > > > > otherwise, enduser may be confused. > > > > To distinguish between the two, I now report the kernel pagesize and the > mmu pagesize like so > > KernelPageSize: 64 kB > MMUPageSize: 4 kB > > This is running a kernel with a 64K base pagesize on a PPC970MP which > does not support 64K hardware pagesizes. > > Does this make sense? Hmmm, Who want to this infomation? I agreed with - An administrator want to know these page are normal or huge. - An administrator want to know hugepage size. (e.g. x86_64 has two hugepage size (2M and 1G)) but above ppc64 case seems deeply implementation depended infomation and nobody want to know it. it seems a bottleneck of future enhancement. then I disagreed with - show both KernelPageSize and MMUPageSize in normal page. I like following two choice 1) in normal page, show PAZE_SIZE because, any userland application woks as pagesize==PAZE_SIZE on current powerpc architecture. because fs/binfmt_elf.c ------------------------------ static int create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, unsigned long load_addr, unsigned long interp_load_addr) { (snip) NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); /* pass ELF_EXEC_PAGESIZE to libc */ include/asm-powerpc/elf.h ----------------------------- #define ELF_EXEC_PAGESIZE PAGE_SIZE 2) in normal page, no display any page size. only hugepage case, display page size. because, An administrator want to hugepage size only. (AFAICS) Thought? -- 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