From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0FC382AE66 for ; Wed, 3 Sep 2025 09:32:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756891958; cv=none; b=j6S6EwmPla5FQK3Zrybh4TJffgCbp3eZLcyWaOIonX/BoWpuK3vEjNBw7v1WvViVfLb1yMfXTiU2p+13ZOuSqXhZAq8qrM1qlssP2VfcVsSGzMn6mz+lOg5k/rzf76MtXz3jQMlGK02ECvrjsJR58e1zo3cnsd4Z36Qmhb+ciBQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756891958; c=relaxed/simple; bh=QYNEiv8UzZcglF4OuHMoI1sYm9C7MmUjrT8VXMrcbjs=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=DeinTKAKCCaMGa4ykR4+W1PV6uVJOfgzzc2jbAAxDGPnP6HBjqVb4iAJIRHMHicPrnBG3YXxk9yKyc2nKTIYDHLPubOvLY+V8/i7sN9hFKckMVw2Ykh0/U/1sYsaYlUmHHmwli2ouBaLBRm3LWlqYEJ1DhSMeAEkgJIy1vyIXAE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qhfLccV8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qhfLccV8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A583EC4CEF7 for ; Wed, 3 Sep 2025 09:32:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756891957; bh=QYNEiv8UzZcglF4OuHMoI1sYm9C7MmUjrT8VXMrcbjs=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=qhfLccV8/Wbfuwadslg9tMoSbyC9NvfNemfzNfxSH06nEDnEN0sNAWr77z/XZ8n9J 9VfNzkq4/ecF1fmyWEYvi+TEKFq8YzUvonjCkDUs9OAqZkgBBDCbe2gugiQYPpdaol X6b6WfUD71CUarVo/NS1fFB5p3xaogSGU6DU+p4va/RS1u0jfd3T0UwXKkF+ESNYh7 Z9g4X1DWTGA0TnA39LqW/05YHGpCm9C9d65MPwAD8TYxHTOtJ8vuvUboATXt8PyvVg y/nAbH+p7iBztJIeDNbx4bkVnHUwusXDiQyKpxkSVTpwDSm2G4C+cG1rWD4c/4GUJS pdFRWp+53f01Q== Received: by mail-yb1-f172.google.com with SMTP id 3f1490d57ef6-e970acf352fso5662815276.2 for ; Wed, 03 Sep 2025 02:32:37 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCWVI6gBuFznJOvOmMd6YyuqKztWensJF7PIrIr6cvRpyN9gbY+E1ZR/2zeeL/IDLAmClYIM6vwT@vger.kernel.org X-Gm-Message-State: AOJu0YzEFz+Rw2H7Ylaib6nsC5TDQh693uLK1imYqQB05T1LTJ/APZI8 2+UeuyoeM0Bz1js8XkLtpumCNlEFoapN4idMtc0NgtWRk/DjDuMhwCUC9mOnX0vE2lIVbNiBHO4 C6O+P9OyDJ15y1L7yhKg6bdWOPba84wMJurRYG398Ow== X-Google-Smtp-Source: AGHT+IHVyg4p5QR0RAptgKvMSgPMubewuNwv+4U8GLEeqLb+YipS9iGNECUENqyGY22+4BFCeDQZqDuyHgVV9qNx8gs= X-Received: by 2002:a05:690c:6d8c:b0:722:6a6c:c010 with SMTP id 00721157ae682-7227633350bmr137460257b3.8.1756891956703; Wed, 03 Sep 2025 02:32:36 -0700 (PDT) Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: In-Reply-To: From: Chris Li Date: Wed, 3 Sep 2025 02:32:25 -0700 X-Gmail-Original-Message-ID: X-Gm-Features: Ac12FXybUwxod4Em_QKVug5j6Ua_Z4DLXXFTPr86WOiopqyMskJfrqtzgT6b41k Message-ID: Subject: Re: [PATCH 1/4] mm/swap, memcg: Introduce infrastructure for cgroup-based swap priority To: YoungJun Park Cc: =?UTF-8?Q?Michal_Koutn=C3=BD?= , akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, shikemeng@huaweicloud.com, kasong@tencent.com, nphamcs@gmail.com, bhe@redhat.com, baohua@kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, gunho.lee@lge.com, iamjoonsoo.kim@lge.com, taejoon.song@lge.com, Matthew Wilcox , David Hildenbrand , Kairui Song Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Sep 1, 2025 at 3:40=E2=80=AFPM Chris Li wrote: > You are missing the fact that you need to track two sets of the tier mask= . > the "swap.ters" is a local tiername you need to track. Default is empty. > > The runtime tier set is the local tier mask walk to the parent, and > collect all parent local bitmasks and aggregate into an effective set. > The effective tier bitmask is used as the swap allocator. > > What you purpose still has the same problem at: > 1) parent "- +ssd" > 2) child "' # same as parent. > > If we do what your proposal is. Child will have "ssd" on the bit mask > at creation > When parents remove the "ssd". the child will keep having the "ssd". > > In my original proposal, if a parent removes ssd then the child will > automatically get it as well. > > I am not happy that you keep introducing change to my proposal and > introduce the same buggy behavior again and again. Please respect my > time, I am spending my long weekend writing an email to you. Please > don't introduce the same bug again just for the sake of changing > behavior. Be careful and think through what you are proposing. Please accept the sincere apology from me. I was grumpy, sorry about that. I was under pressure to be somewhere else but this email is taking longer than I expected to write. I let my bad temper get the better of me and I am sorry about that. You might not have realized that the proposal you made has the same kind of buggy behavior for the usage case where the change of the parent and the child gets it. One side note, I do want to rate limit the new proposals I have to defend against. On the other hand, when you make a proposal to change, you have no way to predict where I will consider it good or bad. Otherwise we don't need to have this discussion. My hash reply is uncalled for and I realized that now. I am over it now, let's put this behind us and continue our discussion. Best regards, Chris