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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD3F9C43334 for ; Thu, 9 Jun 2022 02:36:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 256AD6B0073; Wed, 8 Jun 2022 22:36:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 205176B0074; Wed, 8 Jun 2022 22:36:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0CD4A6B0075; Wed, 8 Jun 2022 22:36:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id F2F906B0073 for ; Wed, 8 Jun 2022 22:36:18 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id C914B120B91 for ; Thu, 9 Jun 2022 02:36:18 +0000 (UTC) X-FDA: 79557133236.28.9883BC2 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) by imf18.hostedemail.com (Postfix) with ESMTP id 6A6B11C005D for ; Thu, 9 Jun 2022 02:36:18 +0000 (UTC) Received: by mail-ej1-f53.google.com with SMTP id v1so34129989ejg.13 for ; Wed, 08 Jun 2022 19:36:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oalZybOvgg/9wPGDBWM/x3Yjhi0IprjkXCuAt/oUJMY=; b=OfCQpFk+GaNQx+y4Mxak+pHFIjSpLTODa882zT5wsUwLYSjix4X/UrY0ZB/qa6+CzE IvSo8hnCK66L/BGl7ihM0gXFdNmwt9LB94W32vxiOppnFc3EFAVm4p7v9InsU0QwfId8 xkLoNG0N+QO3tOq08NNaRi7Od/g61aNfrRDdHyZ0szmbK2qIJFhaZZ1i1Nq34myCwErd tAUjwXCEBhOP6pKFztjpkiKbbVB3RDoNE1KnMOhdHOTsg/qDf+kToQCYaxC0QiQDse1H B0iym+1Hb8jEg7zseclYn1jPRQ9ayLgja3uXFPz4XsUuWaTzAelElHR4+B1Ijmab5BYy NkOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oalZybOvgg/9wPGDBWM/x3Yjhi0IprjkXCuAt/oUJMY=; b=C05kQbIW1Ifp/ppr4iEKcO6mcJ4CnP04L9bClKRPG1cvSzBXxh1Stoq8ErkKde04E9 2yGcoosJOyNwwlA825aFXtslBWOgTQZpjkP1ujuK+WmVrfmyVfD7rd8pudmQg3KbAW7n zWyXJJLCfxQ8myqBNmm8qFtXV2tjByKxTkcKTzWksZEd5aIvLvG0BMhPoFNZBlwnrxnh O1PyMtuS10nqxrTIF58sGT5MVlbwEXuYSxRPCtptIk5mWhZBNdh+ggAaeW3NFcZ1Lbio kcuJ8t+JNoSiApHo/pnU069bWhrfOllVx1y5+KJFPJeYjbqfCiPSoGjXOdXus6ZisT33 oaNA== X-Gm-Message-State: AOAM533PzTyaEvSHy8ptn87ZcA/LQKqKFIVrSxJHz6hXszI7Nznafq8W rRWV624wyKPDUROl0Y2pBSpXMyjZpfRS3c6vOMM= X-Google-Smtp-Source: ABdhPJx0YisosEKVEZ27qwd3nEtVr6FK+67SfxgiWY8AyA2LibCLyviipQr6vRNN56Z/d3m55l/LARCRhn10zI/lP28= X-Received: by 2002:a17:907:7f91:b0:6ff:c1a:2e8e with SMTP id qk17-20020a1709077f9100b006ff0c1a2e8emr32748885ejc.70.1654742177016; Wed, 08 Jun 2022 19:36:17 -0700 (PDT) MIME-Version: 1.0 References: <20220606032709.11800-1-xinhuanpeng9@gmail.com> In-Reply-To: From: xin huanpeng Date: Thu, 9 Jun 2022 10:36:05 +0800 Message-ID: Subject: Re: [PATCH] mm: add a new emergency page migratetype. To: David Hildenbrand Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xinhuanpeng Content-Type: multipart/alternative; boundary="000000000000a7eee705e0faaf4c" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1654742178; a=rsa-sha256; cv=none; b=62VaGmPeuzJshPSYSqT0/s1lF92Wh1JZ3fPdT914E3cf5JKIsZzeMdrU9OD92jTwx4JXEa w0H+x9jXAsNqY9qfR0U8FfOEHnHlQGKtM8bMazNP4GqMhxvRAz/2N6fLLHZTgVooyBtIHp 0wK0sD6e+N/pv8+tkKbvj86voKVKVx8= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=OfCQpFk+; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf18.hostedemail.com: domain of xinhuanpeng9@gmail.com designates 209.85.218.53 as permitted sender) smtp.mailfrom=xinhuanpeng9@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1654742178; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=oalZybOvgg/9wPGDBWM/x3Yjhi0IprjkXCuAt/oUJMY=; b=OuabKs7hadtYfeO+UJx89Z6qb+BllfnkjS8vnG78p7Dyt8URsEJ9WjtzDPO/Fo/FN11u1a ePZB1EDvIhkVDKcqAqi4drH770G11NJ0Gfx/1U0ysOMlsnRgHaTwijoOor5dll82B09Pcm NlUyg9NWVKzwLl8J21nA735Y46pgBd0= X-Rspamd-Queue-Id: 6A6B11C005D X-Rspam-User: Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=OfCQpFk+; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf18.hostedemail.com: domain of xinhuanpeng9@gmail.com designates 209.85.218.53 as permitted sender) smtp.mailfrom=xinhuanpeng9@gmail.com X-Stat-Signature: 9875owibjmez83zpg7br1sy86e5bebzm X-Rspamd-Server: rspam02 X-HE-Tag: 1654742178-639737 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000005, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --000000000000a7eee705e0faaf4c Content-Type: text/plain; charset="UTF-8" Thank you very much for your reply. We will continue to improve according to your comments. On Tue, Jun 7, 2022 at 8:55 PM David Hildenbrand wrote: > On 06.06.22 05:27, Huanpeng Xin wrote: > > From: xinhuanpeng > > > > add a new page migratetype reserved for > > non-costly non-NOWARN page allocation failure. > > Sorry to say, but this patch description is not expressive enough. I > have absolutely no clue what you are trying to achieve and why we should > care. > > Especially, why do we care about locally grouping these allocations > (that's what pageblock flags are for after all)? > > Your Kconfig option is also not particularly user friendly to read either: > > "This enables the migration type MIGRATE_EMERGENCY,which reserves > a small amount of memory for non-costly non-NOWARN page allocation > failure." > > Usually we reserve memory via different mechanisms, like atomic > reserves? Why can't something like that be used. > > On first sight, defining a new pageblock migratype feels wrong to me. > But then, I have no clue what you are actually trying to achieve. > > -- > Thanks, > > David / dhildenb > > --000000000000a7eee705e0faaf4c Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Thank you very much for your reply. We will continue to im= prove according to your comments.

<= div dir=3D"ltr" class=3D"gmail_attr">On Tue, Jun 7, 2022 at 8:55 PM David H= ildenbrand <david@redhat.com>= wrote:
On 06.06= .22 05:27, Huanpeng Xin wrote:
> From: xinhuanpeng <xinhuanpeng@xiaomi.com>
>
> add a new page migratetype reserved for
> non-costly non-NOWARN page allocation failure.

Sorry to say, but this patch description is not expressive enough. I
have absolutely no clue what you are trying to achieve and why we should care.

Especially, why do we care about locally grouping these allocations
(that's what pageblock flags are for after all)?

Your Kconfig option is also not particularly user friendly to read either:<= br>
"This enables the migration type MIGRATE_EMERGENCY,which reserves
=C2=A0a small amount of memory for non-costly non-NOWARN page allocation =C2=A0failure."

Usually we reserve memory via different mechanisms, like atomic
reserves? Why can't something like that be used.

On first sight, defining a new pageblock migratype feels wrong to me.
But then, I have no clue what you are actually trying to achieve.

--
Thanks,

David / dhildenb

--000000000000a7eee705e0faaf4c--