From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f48.google.com (mail-wg0-f48.google.com [74.125.82.48]) by kanga.kvack.org (Postfix) with ESMTP id C4F4D6B0038 for ; Wed, 6 May 2015 07:29:43 -0400 (EDT) Received: by wgyo15 with SMTP id o15so8082467wgy.2 for ; Wed, 06 May 2015 04:29:43 -0700 (PDT) Received: from kirsi1.inet.fi (mta-out1.inet.fi. [62.71.2.195]) by mx.google.com with ESMTP id a9si1746323wie.64.2015.05.06.04.29.41 for ; Wed, 06 May 2015 04:29:42 -0700 (PDT) Date: Wed, 6 May 2015 14:29:39 +0300 From: "Kirill A. Shutemov" Subject: TLB flushes on s390 Message-ID: <20150506112939.GA17739@node.dhcp.inet.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: Martin Schwidefsky , Heiko Carstens Cc: linux-mm@kvack.org Hi, I'm looking though s390 code around page table handling and I found that in many places s390 does tlb flush before changing page table entry. Let's look for instance on pmdp_clear_flush() implementation on s390. It's implemented with pmdp_get_and_clear() which does pmdp_flush_direct() *before* pmd_clear(). That's invert order comparing to generic pmdp_flush_direct(). The question is what prevents tlb from being re-fill between flushing tlb and clearing page table entry? -- Kirill A. Shutemov -- 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