From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lgeamrelo12.lge.com (lgeamrelo12.lge.com [156.147.23.52]) (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 425B43E49E6 for ; Tue, 21 Jul 2026 16:13:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.147.23.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784650397; cv=none; b=N0hAmDB50Uut1DwBdAOwFRfFZTx8H6DwF1NnHfWxCodjDKgrO38kevxz2Z3GChbQkN98zY+8AIyzGZhBt6ErwQKm4NLZM6Nt6/5F6KO/2FXzp5E8Elh3l3kLDeoN28n5vadMzsDVVFCNko0P8ALN2Qb6VzNqRdCQzMYXTVYWNsQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784650397; c=relaxed/simple; bh=CGrfDhCfR8ss2UfSi1waFxauVhaxJybP/DBRGZK15CA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DqkQ6A6VH3zFrTeky6eghZgk6YUHunoUGPmYa7e/gKEVnrSeSRw2gRPUqzter96aqhUzbrToAqt5thGCL1HzcWefe+exo/c4qYgCj9qr271h7PNRhiD80Om6TaIkrW8+iQx4vUGfmbgHeNi8Bjcq34q1dDwjj6KmVvlGMvIMTeU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lge.com; spf=pass smtp.mailfrom=lge.com; arc=none smtp.client-ip=156.147.23.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lge.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lge.com Received: from unknown (HELO lgemrelse6q.lge.com) (156.147.1.121) by 156.147.23.52 with ESMTP; 22 Jul 2026 01:13:10 +0900 X-Original-SENDERIP: 156.147.1.121 X-Original-MAILFROM: youngjun.park@lge.com Received: from unknown (HELO yjaykim-PowerEdge-T330) (10.177.112.156) by 156.147.1.121 with ESMTP; 22 Jul 2026 01:13:09 +0900 X-Original-SENDERIP: 10.177.112.156 X-Original-MAILFROM: youngjun.park@lge.com Date: Wed, 22 Jul 2026 01:13:09 +0900 From: Youngjun Park To: Xueyuan Chen Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, baohua@kernel.org, zhaonanzhe@xiaomi.com, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, qi.zheng@linux.dev, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, baolin.wang@linux.alibaba.com, hughd@google.com Subject: Re: [RFC PATCH v3 2/4] mm: distinguish large folio swap allocation failures Message-ID: References: <20260717122514.51514-1-xueyuan.chen21@gmail.com> <20260717122514.51514-3-xueyuan.chen21@gmail.com> 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: <20260717122514.51514-3-xueyuan.chen21@gmail.com> On Fri, Jul 17, 2026 at 08:25:12PM +0800, Xueyuan Chen wrote: ... > local_lock(&percpu_swap_cluster.lock); > if (!swap_alloc_fast(folio)) > @@ -1730,11 +1734,16 @@ int folio_alloc_swap(struct folio *folio) > } > /* Need to call this even if allocation failed, for MEMCG_SWAP_FAIL. */ > - if (unlikely(mem_cgroup_try_charge_swap(folio, folio->swap))) > + if (unlikely(mem_cgroup_try_charge_swap(folio, folio->swap, > + &nr_swap_pages))) { > swap_cache_del_folio(folio); IMHO, If we get here the allocation succeeded and only the charge failed, so we already know global swap space exists. (And also swap_cache_del_folio right above even puts the slots back, so nr_swap_pages goes up again) Could we just take the margin and decide -E2BIG or -ENOMEM from that? Youngjun