From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) (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 71CC43A544E for ; Mon, 1 Jun 2026 13:21:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780320108; cv=none; b=uOTZhREO8FTSr4gt5X7jkDR4kzlu0XXxoe11MheTWqA9JcjKBSNDuLaIQjSjElwp2F3dOJLGXkuj722CcP6sOWhuEozoUS/KaAxBUGK/xPzw2sFHs27qBVqBcLXKeRVBpSMksoJi/PfJOJ9Ux2cpFXfCIoZBZFmhDKmrYhX5SlU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780320108; c=relaxed/simple; bh=ebCKDyfzRHth1EEtv0OJWII8KGWcouKKxG+A66kpqZc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=qme/4q8XDpVI96OlkT47MQDB+RBXf0MnFqAbqaCFjgWb47FKG0Tj6OEUP+vlfhaY7TVSsAsV2t4bZSIHfqN/t74rASc5LOL7xF6y3dFnZWe3TWq9QLfMBwnpPL4nV1AA+THBhlONkWZYzjM3Z7SDCU1lAB5feRRisAIBxjqEV+M= 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=VS5JAOKQ; arc=none smtp.client-ip=91.218.175.178 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="VS5JAOKQ" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1780320104; 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=io/nWNe86lhvjJWsubKx+bggG1DCxvRqyS7n1xMOY/s=; b=VS5JAOKQy+tQJA3X0tyQ+VPzBr0usyd3U2XwNbpi+S72w1R3mZ0hN5nhEjzmdeRGKdqsIZ ml1rA0qowCaJ3Wb8Z7oks84ILx8+GdHCezYkfd1MjmySVCDLBuMExOPVCJSy0/4XV/4a04 bnannMrYBKhS4p10E5HXbvqyDtBo3RE= From: Lance Yang To: hannes@cmpxchg.org, baolin.wang@linux.alibaba.com Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, shakeel.butt@linux.dev, mhocko@kernel.org, david@fromorbit.com, roman.gushchin@linux.dev, muchun.song@linux.dev, qi.zheng@linux.dev, yosry.ahmed@linux.dev, ziy@nvidia.com, liam@infradead.org, usama.arif@linux.dev, kas@kernel.org, vbabka@kernel.org, ryncsn@gmail.com, zaslonko@linux.ibm.com, gor@linux.ibm.com, baohua@kernel.org, dev.jain@arm.com, lance.yang@linux.dev, npache@redhat.com, ryan.roberts@arm.com, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 9/9] mm: switch deferred split shrinker to list_lru Date: Mon, 1 Jun 2026 21:21:35 +0800 Message-Id: <20260601132135.14272-1-lance.yang@linux.dev> In-Reply-To: <20260527204757.2544958-10-hannes@cmpxchg.org> References: <20260527204757.2544958-10-hannes@cmpxchg.org> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On Wed, May 27, 2026 at 04:45:16PM -0400, Johannes Weiner wrote: [...] >diff --git a/mm/swap_state.c b/mm/swap_state.c >index 04f5ce992401..9c3a5cf99778 100644 >--- a/mm/swap_state.c >+++ b/mm/swap_state.c >@@ -465,6 +465,16 @@ static struct folio *__swap_cache_alloc(struct swap_cluster_info *ci, > return ERR_PTR(-ENOMEM); > } > Shouldn't this be limited to anon swapin? e.g. vmf && vma_is_anonymous(vmf->vma) >+ if (order > 1 && folio_memcg_alloc_deferred(folio)) { __swap_cache_alloc() is also used by shmem direct swapin, so shmem can get here too when handling a large swap entry: shmem_get_folio_gfp() shmem_swapin_folio() shmem_swap_alloc_folio() swapin_sync() swap_cache_alloc_folio() __swap_cache_alloc() folio_memcg_alloc_deferred() @Baolin please correct me if I got it wrong :) folio_memcg_alloc_deferred() itself doesn't filter shmem out either; it only allocates the memcg list_lru metadata for deferred_split_lru: int folio_memcg_alloc_deferred(struct folio *folio) { if (mem_cgroup_disabled()) return 0; return folio_memcg_list_lru_alloc(folio, &deferred_split_lru, GFP_KERNEL); } Since deferred_split_lru only queues anon large folios, doing this for shmem swapin doesn't buy us anything :) Maybe I'm missing something, just wanted to raise it. >+ spin_lock(&ci->lock); >+ __swap_cache_do_del_folio(ci, folio, entry, shadow); >+ spin_unlock(&ci->lock); >+ folio_unlock(folio); >+ /* nr_pages refs from swap cache, 1 from allocation */ >+ folio_put_refs(folio, nr_pages + 1); >+ return ERR_PTR(-ENOMEM); >+ } >+ > /* memsw uncharges swap when folio is added to swap cache */ > memcg1_swapin(folio); > if (shadow) >-- >2.54.0 > >