From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-rdma-owner@vger.kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 0D66DC2BB3F
	for <linux-rdma@archiver.kernel.org>; Sun, 19 Nov 2023 01:04:56 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S229705AbjKSBE5 (ORCPT <rfc822;linux-rdma@archiver.kernel.org>);
        Sat, 18 Nov 2023 20:04:57 -0500
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33088 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S229610AbjKSBE4 (ORCPT
        <rfc822;linux-rdma@vger.kernel.org>); Sat, 18 Nov 2023 20:04:56 -0500
Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54195194
        for <linux-rdma@vger.kernel.org>; Sat, 18 Nov 2023 17:04:52 -0800 (PST)
Message-ID: <62016bca-26fc-4c86-beaa-90560a060c24@linux.dev>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1;
        t=1700355890;
        h=from:from:reply-to:subject:subject:date:date:message-id:message-id:
         to:to:cc:mime-version:mime-version:content-type:content-type:
         content-transfer-encoding:content-transfer-encoding:
         in-reply-to:in-reply-to:references:references;
        bh=OpVkl+3ObwgsEaMCKfvfhRWQ0LbonVVeDpSfF3JGJtg=;
        b=lz7JiBnP9h2kvOzZWvBn1FNV3+69ISXk6XiiZ2Vw9tfWDdOks9/Xkn7vGQm+92/s9xVhRv
        MlxgVwTgs/3+CqZPgELbFQOE0tjlbG/R8fKuZWMRWpU2Saaaqx6SGrBz7sstqYfn0JGJ0l
        cI4Mx+IcvMOK3dQ5Ik2JRzdizXUgzqQ=
Date:   Sun, 19 Nov 2023 09:04:44 +0800
MIME-Version: 1.0
Subject: Re: [PATCH for-rc 1/3] RDMA/core: Fix umem iterator when PAGE_SIZE is
 greater then HCA pgsz
To:     "Marciniszyn, Mike" <mike.marciniszyn@intel.com>,
        "Saleem, Shiraz" <shiraz.saleem@intel.com>,
        "jgg@nvidia.com" <jgg@nvidia.com>,
        "leon@kernel.org" <leon@kernel.org>,
        RDMA mailing list <linux-rdma@vger.kernel.org>
References: <20231115191752.266-1-shiraz.saleem@intel.com>
 <20231115191752.266-2-shiraz.saleem@intel.com>
 <093f16a6-2948-4103-8d27-ea349aa6909c@linux.dev>
 <SA1PR11MB6895E230B7CFE2D293DAFAA886B6A@SA1PR11MB6895.namprd11.prod.outlook.com>
X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers.
From:   Zhu Yanjun <yanjun.zhu@linux.dev>
In-Reply-To: <SA1PR11MB6895E230B7CFE2D293DAFAA886B6A@SA1PR11MB6895.namprd11.prod.outlook.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Migadu-Flow: FLOW_OUT
Precedence: bulk
List-ID: <linux-rdma.vger.kernel.org>
X-Mailing-List: linux-rdma@vger.kernel.org


在 2023/11/18 22:54, Marciniszyn, Mike 写道:
>>> From: Mike Marciniszyn <mike.marciniszyn@intel.com>
>>>
>>> 64k pages introduce the situation in this diagram when the HCA
>> Only ARM64 architecture supports 64K page size?
> Arm supports multiple page_sizes.   The problematic combination is when
> the HCA needs a SMALLER page size than the PAGE_SIZE.
>
> The kernel configuration can select from

Got it. Thanks a lot. On ARM architecture, some kernel configurations 
can be

selected to enable multiple page sizes.

>
>> Is it possible that x86_64 also supports 64K page size?
>>
> x86_64 supports larger page_sizes for TLB optimization, but the default minimum is always 4K.

On x86_64 architecture, how to enable a not-4k page size? For example, 
16K, 64K and so on.

Thanks a lot.

Zhu Yanjun

>
> Mike