From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (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 F2DB740D58C for ; Mon, 29 Jun 2026 13:56:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782741365; cv=none; b=mBdyr5y9urxjUUhdxqWhwZmZIS41F3nuZ8l6wc+x1jV7jPOmw4rjNm6Cf5at+RlWRpXp9/+XsAm25G/tJL0Z9NzSwG53z5E4hgzp5A+ItaIkNNeLXxh9aRe0baEF9KCn/ety6g0KpNSIwhTdfJecRlrkTssHVXqhad0BoUF1XS0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782741365; c=relaxed/simple; bh=6XtzG8WpfTtrXq40wO3KKb46pjiIEvSDAqggmkVd0qs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jC16yMq/fy+3c3S5vG4st/z8gVw1QgJEURRvt8cPbiLdopW1Q7eZxbkrhD5ZImR8Xrzes9isn9aHOWV9uSra8b6YnIiW/gRBKf4a0EsoZDIz/GnsKHq7yOKXlV1/IKtfrnL3dZch1zwYO3/M7U2XGQ6rd4RR3lvWP62qwm2tuIc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=vgBC37IY; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="vgBC37IY" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1782741362; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qeFjIxuSYF8J0DkeUYc5tlTp3RN5B8ri+h7u1iPzWr4=; b=vgBC37IYOOiKPtFawXBcTU6sMT7fDEffIeVaKr/sh5bVKq5JrJGadZpjOZisxsXgexuD4H tTZzz9bXBnjufHE9XusquZqKIeZj7c2CqDNVCBCZuDbxz9i3zoO5YIhP4d6j5tbStT2OoP hDVigcnLBKFNRjQWd/mkod5upskV/00= Date: Mon, 29 Jun 2026 14:55:57 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2 2/2] mm/vmpressure: split v1 userspace eventfd code into vmpressure-v1.c To: =?UTF-8?Q?Michal_Koutn=C3=BD?= Cc: Andrew Morton , david@kernel.org, linux-mm@kvack.org, hannes@cmpxchg.org, tj@kernel.org, shakeel.butt@linux.dev, roman.gushchin@linux.dev, liam@infradead.org, linux-kernel@vger.kernel.org, ljs@kernel.org, mhocko@suse.com, rppt@kernel.org, surenb@google.com, vbabka@kernel.org, kernel-team@meta.com References: <20260629130042.2649505-1-usama.arif@linux.dev> <20260629130042.2649505-3-usama.arif@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Usama Arif In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 29/06/2026 14:34, Michal Koutný wrote: > On Mon, Jun 29, 2026 at 05:59:37AM -0700, Usama Arif wrote: >> This split is the first step toward eventually making vmpressure >> CONFIG_MEMCG_V1 only. The v2 in-kernel socket pressure path >> (tree=false) cannot be removed today immediately: PSI is not an >> exact replacement for vmpressure, and switching networking socket-buffer >> back-off to PSI > > (Here I understand PSI is a different and differntly scope metric) but > what does it mean when you write that tree=false cannot be removed but > the other patch bails out from vmpressure() (i.e. nothing is updated > anyway)? So the first patch bails out for cgroup v2 for tree = true only. For tree = false, it doesn't bail out, and is still used for networking socket-buffer back-off. I think that is a whole another scope of work switching to PSI. Hope that makes sense? Thanks, Usama