From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta1.migadu.com (out-188.mta1.migadu.com [95.215.58.188]) (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 C1B9F3F7869 for ; Wed, 18 Mar 2026 20:13:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773864788; cv=none; b=FzGvUB80CppJUNJ9iKJNGG3g9tk59JxoZb0MiNWqtNHVLwo7wyHrVLTfbexOpjQ34hA7/OWgBfMREtXIJvjMyU3yG6FGioqZVflr/H1Nz/6AEL0wzT8ZCgU/EF7DohklcsnU484gRdFcENJskXRWzXXj9Qeom10qJJACYgfaE/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773864788; c=relaxed/simple; bh=qUi21TNlA51zGH4mlqLf0sSBssgZnpvMVNzKrUIs/a8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=C0i5KxnrGIyHPmwGhZJCy4Bv1qSIWnwOX07NyTwFkfrAEbSBT1AqL8wE7Cgqi3utEW98SmIn5KnuGd3pd+uOFlV1AhqYf8fluHMywggMWwAH0iOSYkbayI3FejYYMNqTPIcHd6pB065b+Ds6MStREEWLFnyBAmouh8RGWV84eRQ= 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=BfTCnSMq; arc=none smtp.client-ip=95.215.58.188 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="BfTCnSMq" Date: Wed, 18 Mar 2026 13:12:56 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1773864784; 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: in-reply-to:in-reply-to:references:references; bh=8S68DA/9ME5Lv59GmMoHWUV46BnyFgsIWC59IN4av2k=; b=BfTCnSMqJYyl4URiq5AlrUuWV/Z0vub4mgczj/BcqbocIUs2nytukQZMA/lejIMPfjwDTF GGv8kiQsCohZhRGkdCkKOFTFNiL31rSqDWWXSkAOKalq7KLpLHSI1klibeZd71D9QX9j3u bN3b3HZ14/I8SWIIKL8Rh8LR0rUJzNg= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Shakeel Butt To: Johannes Weiner Cc: Andrew Morton , David Hildenbrand , Yosry Ahmed , Zi Yan , "Liam R. Howlett" , Usama Arif , Kiryl Shutsemau , Dave Chinner , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/7] mm: list_lru: lock_list_lru_of_memcg() cannot return NULL if !skip_empty Message-ID: References: <20260318200352.1039011-1-hannes@cmpxchg.org> <20260318200352.1039011-2-hannes@cmpxchg.org> 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: <20260318200352.1039011-2-hannes@cmpxchg.org> X-Migadu-Flow: FLOW_OUT On Wed, Mar 18, 2026 at 03:53:19PM -0400, Johannes Weiner wrote: > skip_empty is only for the shrinker to abort and skip a list that's > empty or whose cgroup is being deleted. > > For list additions and deletions, the cgroup hierarchy is walked > upwards until a valid list_lru head is found, or it will fall back to > the node list. Acquiring the lock won't fail. Remove the NULL checks > in those callers. > > Reviewed-by: David Hildenbrand (Arm) > Signed-off-by: Johannes Weiner Acked-by: Shakeel Butt