From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-129.mta0.migadu.com [91.218.175.129]) (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 2621139936D for ; Wed, 26 Aug 2026 18:30:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.129 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787769060; cv=none; b=vC3WF4LO/3gC9q9cKWb9ydRI2LFZ1/x+tJglDe/OajBzNpepaLyFiVhA/BEP7apN/cSyyQ1trKwR7sMvwiTqeLNtI6+3biFGOekYywpU0WfElHjg1Ha4SHpCP0wG+xcPUHaj0cdpODDXEWQHDMA+r1BmbfzLce6SxqGfS6ioP0A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787769060; c=relaxed/simple; bh=sRp/KET3iYMwTo3XmECBCWWEcdW7TQWTf+Msi3bdCOU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OWImM0KlaBcYuPw6Q9/CEZp4NNqSN6OUYCop1hJQOk4QFSQ+8aw6Tre+e0NAlRmpfrb+7dyxrQqZdZnz3ZVrXTJswmg1A7nlR8FC4v3ivS3fbPvLkuDZ4cGkvClPRhfrDN5TUEkAU3m3oXt9eWfa4MgVRkWhPEOBsV/S3kOoRG8= 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=ovaPIb8T; arc=none smtp.client-ip=91.218.175.129 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="ovaPIb8T" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=sRp/KET3iYMwTo3XmECBCWWEcdW7TQWTf+Msi3bdCOU=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787769038; v=1; x=1788373838; b=ovaPIb8TvskgL8WDU9ja1T6dEM57U/m4FBjcA/glxJXH+shadcKUF6iApMrCpMKuER/oRTtb LIMMQ/Nhq9KAsx1BCTOp7HFAGcmMLrx/LXKJ8Z0HKFI3kaGZUz9AvwEpKrxwoni0KsBkrjhy8EH PRdNjNGMQoS3RqUTREhcvbwM= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost (2a03:2880:10ff:51::) by smtp.migadu.com with ESMTPS id cf2c048dfc5b5d89; Wed, 26 Aug 2026 18:30:37 +0000 X-Mizu-Trace-ID: cf2c048dfc5b5d89 X-Migadu-Flow: FLOW_OUT Date: Wed, 26 Aug 2026 11:30:36 -0700 From: Shakeel Butt To: Ridong Chen Cc: Andrew Morton , Johannes Weiner , David Hildenbrand , Michal Hocko , Qi Zheng , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Davidlohr Bueso , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ridong Chen Subject: Re: [PATCH] mm/vmscan: drop the combined limit gate in __node_reclaim() Message-ID: References: <20260826124409.35569-1-ridong.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260826124409.35569-1-ridong.chen@linux.dev> On Wed, Aug 26, 2026 at 08:44:09PM +0800, Ridong Chen wrote: > From: Ridong Chen > > __node_reclaim() is called from two paths: node_reclaim() and > user_proactive_reclaim(). > > node_reclaim() already bails out early unless node_pagecache_reclaimable() > is over pgdat->min_unmapped_pages or the reclaimable slab is over > pgdat->min_slab_pages. The identical check inside __node_reclaim() that > guards the shrink_node() loop is therefore redundant for this path. > > user_proactive_reclaim() is proactive reclaim driven by userspace and > should not be gated by the per-node min_unmapped_pages / min_slab_pages > limits at all [1]. With the gate in place, a proactive request is silently > turned into a no-op whenever the node happens to sit below both > thresholds. > > Drop the gate in __node_reclaim() and always run the shrink_node() loop. > The node_reclaim() path is unchanged, since its caller has already applied > the same test; the proactive path is no longer wrongly gated. > > [1] https://sashiko.dev/#/patchset/20260723045718.2052070-1-ridong.chen@linux.dev > Fixes: b980077899ea ("mm: introduce per-node proactive reclaim interface") > Assisted-by: Claude:claude-opus-4-8 > Signed-off-by: Ridong Chen > Acked-by: Johannes Weiner Acked-by: Shakeel Butt