From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f174.google.com (mail-qt1-f174.google.com [209.85.160.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EDFE13FC0 for ; Fri, 17 Sep 2021 04:58:52 +0000 (UTC) Received: by mail-qt1-f174.google.com with SMTP id c19so7749470qte.7 for ; Thu, 16 Sep 2021 21:58:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=RSETynYAaWok9lyPkYvwwM94kyTjrnU1juJzOUQ8/Ug=; b=NunvM/6Wbbyifoo1x2DoS8ywUoYMV7Ef2gqEsZwJpIrZliHOL7Ch7d3hhu3RKN2htf ErJmoucdcDqIUBkfqQ5q8335G40t7FCKEGMKvv0OpiQrbAtTXmVQ+LNvDFL1kAg4xHUU F3PHosOc7kxFEyl+fJZvEAzUcbDADZs2EbcAXu5bgkEHccQzlYCEK3OVRu1emmHyZmnT /LtFHPdg1p/st0PUObAgAWOe3G9GKpLZ1yA7OjRvizom+rL441NTW0a+w+TCh9gv8qnW mfRrvLZGtXfro1jUlztAJY4Bnj+zhtha8z71CHUCfcstfujQ5BzLKy64xBkAvM3cPXYA GPGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=RSETynYAaWok9lyPkYvwwM94kyTjrnU1juJzOUQ8/Ug=; b=xZ0ZkwPSJEjk/PQTkQjvd4Ifd7MSh67IoI/vtq6JhtA31DyZG/YuFBd5OO9V/5Er+q HfX1BH4praZzXp1bdh6SyI4VeoSXXKcJ9ooRyhiK9NtdCBF3qk8yNSAtEoJsGmwTOUwr VBMI2bMhH36TMhV73Q1ZAAS4FZ+f2lqobSQqJLniIcXhVkyvVx3rBHN9/oOlHEsgDtRG l5Fv39sZe18avcmO8Yt2iJbRv9B4kp6LZFpmCFNSBvhIFFHwMVs/RCXxWZNhN/We5h1k ojYsqTiExN2xvKr1sPS0sEUFAm0mgYI63XhMSZFOiRpGJjZFUCqfhHB1Mxo2Zc/hmwPe wuSA== X-Gm-Message-State: AOAM532IaXVsVxS0YVEqtb8iBBNNxIiFMBr3elYpimnNqwOSSLOn6LTt +scKonthOTl7jsCogMYbDQ== X-Google-Smtp-Source: ABdhPJw6JWEXhbwhWdB/W/tXio2pi7htD4NuLH/7NvepOVgP4ZPM+X79LJn2/sc8YA3yBZAHB2arxg== X-Received: by 2002:ac8:5710:: with SMTP id 16mr8329969qtw.393.1631854731874; Thu, 16 Sep 2021 21:58:51 -0700 (PDT) Received: from moria.home.lan (c-73-219-103-14.hsd1.vt.comcast.net. [73.219.103.14]) by smtp.gmail.com with ESMTPSA id x9sm4059552qko.125.2021.09.16.21.58.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Sep 2021 21:58:50 -0700 (PDT) Date: Fri, 17 Sep 2021 00:58:48 -0400 From: Kent Overstreet To: Theodore Ts'o Cc: James Bottomley , Chris Mason , Johannes Weiner , Matthew Wilcox , Linus Torvalds , "linux-mm@kvack.org" , linux-fsdevel , "linux-kernel@vger.kernel.org" , Andrew Morton , "Darrick J. Wong" , Christoph Hellwig , David Howells , "ksummit@lists.linux.dev" Subject: Re: [MAINTAINER SUMMIT] Folios as a potential Kernel/Maintainers Summit topic? Message-ID: References: <17242A0C-3613-41BB-84E4-2617A182216E@fb.com> <33a2000f56d51284e2df0cfcd704e93977684b59.camel@HansenPartnership.com> Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Sep 16, 2021 at 09:42:21PM -0400, Theodore Ts'o wrote: > On Thu, Sep 16, 2021 at 04:16:27PM -0400, Kent Overstreet wrote: > > So I think we're still trying to answer the "what exactly is a folio" > > question.... > > > However, Johannes has been pointing out that it's a real open > > question as to whether anonymous pages should be folios! Willy's > > current code seems to leave things in a somewhat intermediate state > > - some mm/ code treats anonymous pages as folios, but it's not clear > > to me how much.... > > Kent, you raise some good questions, and good points. However, it > seems to me that one of the other sources of the disagreement is the > question of whether this question needs to be answered at all before > the Folios patch can get merged. ... > It seems that part of the frustration is that people seem to agree > that Folios does make things better, and yet they *still* are NACK'ing > the patch series. The argument for why it should not be merged yet > seems to be that it should be doing *more* --- that it doesn't go far > enough. Yeah, I agree 100%, and I've expressed my own frustrations with how the folios discussions have been going (and I could, and will, express some more of those frustrations - later). But, that's water under the bridge. For now, I'm really just trying to drive the technical discussion. I'm not Andrew or Linus, it's not my say whether folios get merged, I'm just trying to dig to figure out what the _actual_ technical points of contention are (and it's taken some real digging...) And having done so, I think the question of whether or not anonymous pages are becoming folios actually is extremely cogent - I think there's a lot of meat to that discussion, and it definitely impacts _squarely_ in MM internals land. So, let's just try to be more forward looking, try to forget the acrimony, and get into that discussion, and remember that we'll all be having beers with each other whenever the fsck LSF actually happens again.