From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1C40C48BDF for ; Fri, 18 Jun 2021 19:47:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 937786127C for ; Fri, 18 Jun 2021 19:47:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231925AbhFRTt2 (ORCPT ); Fri, 18 Jun 2021 15:49:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231151AbhFRTt0 (ORCPT ); Fri, 18 Jun 2021 15:49:26 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F9C8C061760 for ; Fri, 18 Jun 2021 12:47:16 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id x19so5232713pln.2 for ; Fri, 18 Jun 2021 12:47:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :mime-version; bh=eq0N34Elw7O9e3nBxwSL+pENedj11Jkr0/H5vmh3pBo=; b=md5MeIpFhcK2iIApQdDDALKT7hCraWLPVY3CbjtqgJicSzCUh6v5whBrWKvYm9kZPx +vweAivEg59pZRNL+Q6LtzJ8V4rmZjLZJC/dM7v5zPpBbsQg0nMqVD3JnIhd6yklk6Y5 tnWZHSnsL1jw07DChiw4RbShzbMsPc3ybynFJLdK1PVN6tCOofoqrefLlTPQGy1NLtYR ddrwoLzLdY1oQ/QgAm+fd0mQI6wqGZTlQvuIzY7Olj2hCF8CPtqeyQGtx+b2z5NmE74i pWI39ae7i843LtjLzOWU/eneQaxPNAGa0NRPyJS0NFJu0mkBHzglNAawqyENDad+LzyE nkNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version; bh=eq0N34Elw7O9e3nBxwSL+pENedj11Jkr0/H5vmh3pBo=; b=SKeGUbJn3WWFIuywaizijzfIHtLxMRFAnmEtUWwBWyrbJotAQrwRsfdTK2MAcadIVw nloU56+kXRhstQfjedjKkLaTAbQ/gf/8xJqnnl10xBwgZccrquc4uujv9JkKn9VneNQE nW6aaOyKkvFg0XGFn0c6lximE7dDNQdB9oC8coqvZvLpaapMCISg3AoRcANLvJMgRWc3 fLWfBk+qRD6l1f4E4wJAD+wrcKgzR8sn+IxUTcVT1luUu8HKbmug3mYdYzHWMZBSNEyf 57PXBEI3akjQwqah0VJqRy5kTn3u046rdI69oFoK1bM/jMzBevBqGFXk9RcgvGJmQquz u0SQ== X-Gm-Message-State: AOAM531ZG81Sp+6kPaZz6Tx+CYArwZbTo8otT82WNBYyP3TrdQ6j6EAB bO5QYIP+mriXDmOQ6/JeyaUAHQ== X-Google-Smtp-Source: ABdhPJwIj5XwSwiZJe0QhGTCJrTe3ZX8MEoalt16+FuxZ8ezP+RY6l+/5DuS09FY/e3rd9JPPR2OkQ== X-Received: by 2002:a17:902:c1cc:b029:122:52b4:3855 with SMTP id c12-20020a170902c1ccb029012252b43855mr1621009plc.10.1624045635401; Fri, 18 Jun 2021 12:47:15 -0700 (PDT) Received: from [2620:15c:17:3:3a6:a5d0:1984:a150] ([2620:15c:17:3:3a6:a5d0:1984:a150]) by smtp.gmail.com with ESMTPSA id s1sm9601820pgg.49.2021.06.18.12.47.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Jun 2021 12:47:14 -0700 (PDT) Date: Fri, 18 Jun 2021 12:47:13 -0700 (PDT) From: David Rientjes To: Claudio Imbrenda cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, david@redhat.com, linux-mm@kvack.org, Uladzislau Rezki , Nicholas Piggin , Andrew Morton , Catalin Marinas , Thomas Gleixner , Ingo Molnar , Christoph Hellwig Subject: Re: [PATCH v4 1/2] mm/vmalloc: add vmalloc_no_huge In-Reply-To: <20210614132357.10202-2-imbrenda@linux.ibm.com> Message-ID: <1ab3bba4-dc91-4f8-ecd5-b18b17ec6d8@google.com> References: <20210614132357.10202-1-imbrenda@linux.ibm.com> <20210614132357.10202-2-imbrenda@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, 14 Jun 2021, Claudio Imbrenda wrote: > Commit 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings") added > support for hugepage vmalloc mappings, it also added the flag > VM_NO_HUGE_VMAP for __vmalloc_node_range to request the allocation to > be performed with 0-order non-huge pages. This flag is not accessible > when calling vmalloc, the only option is to call directly > __vmalloc_node_range, which is not exported. > > This means that a module can't vmalloc memory with small pages. > > Case in point: KVM on s390x needs to vmalloc a large area, and it needs > to be mapped with non-huge pages, because of a hardware limitation. > > This patch adds the function vmalloc_no_huge, which works like vmalloc, > but it is guaranteed to always back the mapping using small pages. This > new function is exported, therefore it is usable by modules. > > Signed-off-by: Claudio Imbrenda > Reviewed-by: Uladzislau Rezki (Sony) > Acked-by: Nicholas Piggin > Cc: Andrew Morton > Cc: Nicholas Piggin > Cc: Uladzislau Rezki (Sony) > Cc: Catalin Marinas > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: David Rientjes > Cc: Christoph Hellwig Acked-by: David Rientjes