From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 291BC2F26 for ; Tue, 19 Mar 2024 03:01:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710817284; cv=none; b=F+2fic7FDduMsMTiiICF9wwwSmqoTy6VjHouxhLvi7UVJLuimT3jkg45phcsutJ0vz6hXW8dA5EUmn3BUBudPRxCCgI2+5KRXgoB1NvC3ISF1N5tJs0dSC340Lz+4O251plN4UcRLgKar0xPvfqHku+2vdITejOgAIZjrm9oiB0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710817284; c=relaxed/simple; bh=iOjqKZ1LMen7RBQYSaE3Rc5bvdCp6OclfyTv4S1fdZI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SLRcpjWPoP1Z+uCJfTNPgLBRTLnyMCJQ73oN8xe0SNj+Tdw1nv4TLwuUSUfUeLbzVFLVXGPOwiU7aPvSrIIcsOXk/1rtI+X3feMOp2GWI78moCC8o6TDgJNZxQxyrOxcSIC9LwyK83XWOXLHsyE5TOm3PERtaDhzq8qvulRmB8o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=PMBSEe31; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PMBSEe31" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=q+r//xnTa4Swggn0SjTyOA2AYX42tQNVwNF2RqmybzA=; b=PMBSEe318beFqCJgbQI+P4T3pF qOgVRjM+X23Ssfkd9/ZGzcfFX2sdwfFZDo9k9fn7wUf1EzKiEQuDycY4DTeheAfH4A5x/Q1Sd/Pmy NxG3invp4y+M0B0/XB+dpv1RV55s+VUm6Q9dOG49qFqu4p2EoXUJt5POAmPjuY7qZuOgCHAzzfHXe k3UZc4f41XmYRYfeRBX+3URVZzhzNpxYJrr85yvppFf11oQbxokIDemnZks+AuiczP2rZsa45tjrg x+o3jdyZZ3hCKNFpBJSYR90pwjeShqC97ZQO6VmBEgVhP/ph8UqiuHqCBXzxPkqpKucZIkKYMeBFn gKD/5L7Q==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmPiz-00000000zr6-0G1V; Tue, 19 Mar 2024 03:01:13 +0000 Date: Tue, 19 Mar 2024 03:01:12 +0000 From: Matthew Wilcox To: Zhaoyang Huang Cc: =?utf-8?B?6buE5pyd6ZizIChaaGFveWFuZyBIdWFuZyk=?= , Andrew Morton , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , =?utf-8?B?5bq357qq5ruoIChTdGV2ZSBLYW5nKQ==?= Subject: Re: summarize all information again at bottom//reply: reply: [PATCH] mm: fix a race scenario in folio_isolate_lru Message-ID: References: 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: On Tue, Mar 19, 2024 at 08:48:42AM +0800, Zhaoyang Huang wrote: > BTW, damon_pa_pageout is a potential risk over this race No it isn't. struct folio *folio = damon_get_folio(PHYS_PFN(addr)); if (!folio) continue; if (damos_pa_filter_out(s, folio)) goto put_folio; folio_clear_referenced(folio); folio_test_clear_young(folio); if (!folio_isolate_lru(folio)) goto put_folio; if (folio_test_unevictable(folio)) folio_putback_lru(folio); else list_add(&folio->lru, &folio_list); put_folio: folio_put(folio); It clearly has a folio reference when it calls folio_isolate_lru().