From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f12.google.com (mail-pj2-f12.google.com [74.125.227.140]) (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 AC3484078D1 for ; Tue, 15 Sep 2026 03:31:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.140 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789443067; cv=none; b=tMkiQaWqflKnBDoamCCRjUs8Ny+5UvCAtDY7FilmIFLjBmJBpYnnqVPMzzLSZtJbqhxdu7NlWHBEi8VpjYl3ozek/6jxYufKPNCNNOq2nuhLSQ+x9oC5hB6r6CJkrAs01AgCLptRbspj/RgxaXyDx6GihDUBliyVORkF9OmQHYI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789443067; c=relaxed/simple; bh=s+LsBuhIlfs/w0lJnlNuOPSGSL6VueLtw5zs57ipXSA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d7PWRtNWKAzkFiQ1ASxY+yVMZA6imPkahWoX/wpCIyVN8YcFKR58r4g49yqgmlk2QhdN9n1aOqViBsSmR6L8K/fCXxgv7UhMeU7uTdZpISqrUQe4gY/Z2Ze6irWHVPV2jp15lIfegXe5modhlDIwMJYYwy0l3ElDVyXIDkXEh6c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=FXzv7R3Q; arc=none smtp.client-ip=74.125.227.140 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FXzv7R3Q" Received: by mail-pj2-f12.google.com with SMTP id 98e67ed59e1d1-396ccb652d7so2062816a91.0 for ; Mon, 14 Sep 2026 20:31:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789443059; x=1790047859; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=s7nWcLz8pfZOPdgnq2ek5GovUDuRsqxFmdnwCI+6u6U=; b=FXzv7R3Qg7NQzViOeUapHToz8WDa3tpYZN21PQdHLFcaNsU+9litBh8p1+EYAaGvE1 rS9Q6N8ZSq35kV0PzmyWRA2khovmAId6w8i8HLvxQtJxWDkJ3J5JgU9snmRIkC2zA0wT 3OXgabPmQKBMo45S+RXO0h9kFDLjMkW61pfxLtNqW2xAzw3Qny7n/fWoD4TTMeVBunms f6Gz0XEYAaYZJx/2hd0+qpmXPuUX8rWf6OEAzY6Q806VRwb915n78yH/RvHyLmffOojd Ov6v48IocUCqgafKhGGcEUJJwLMO0raMlRFGVyKhwWKpGi0jQFB2eQ4Qun+XWSljcOK3 N7kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789443059; x=1790047859; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=s7nWcLz8pfZOPdgnq2ek5GovUDuRsqxFmdnwCI+6u6U=; b=xxSPXA9nPOT4KTPvVx9iPPqvfLEYeygQSZ03tpUqB2RQgyDm/NfOS1eJJFdIP2mr+w lnfZpDYH9IBLEJFnfC0CBckk5FkNIPEs1k+96n/oo2uBvM/Lz8jBlLLDke9S2aW1TNv7 kLJOLb5CNrYJ3pNt417OUFGMQ5nKLkKNkGkai0yf8lEdiIbizcwB9igCJzbVn3HHO0iK gNUic+WSFgNZ0SsfUevcuz7rSku3A9dw5u6i/AxCV5wxaRVzE2BeApajkE4/w7JSZsXt R47sJox1rlDeBuyLo8AUJOcuz6i2GctP4LDQcZp7HIGxThiW9sfBoJLIHQqDwmarGrS0 7d/Q== X-Forwarded-Encrypted: i=1; AKwUvBy9wNQLNvaqbin1yQrbDMG1Tyl/3eFRnXZRSsCkZxdWAgcNV4tgvfQLM2cfIvZvtab037NJX73johVdm80=@vger.kernel.org X-Gm-Message-State: AFuF++nqy5Hmvph8uOvZ6dwS+SAfAPLAS4gfugjnyBK0oqqQl5pcptcr axY8XEjnRAwkra/aMnNAIGY5m6UoKFEHSrX8h0eLcQLQi2zcSXRoAyGE X-Gm-Gg: AYBFou2VsoK9t7UUMGwSEj1JVEw2VmB/9BEt3Pux14LbIy/aA1z8EFi33v8k9MjrWJV 7s4lK9iCg+H5qGy8zMyAol6WcGgKeVGU4ZbFDrryt1LSSn9OKdbU8z0K6Lm5me1U/zLdvVrAO9C Gn1DW9h6Mbrz8o7R5HIr9CEHtsKovnSNjMSBg/5vuuEWWb0NE+U8+ojKFuLNOUPAMqwHhDIDcmm xFQJVL+Y+dNghEah6/FdyYnrmt72zcqTVVPFUljRbiJp0IMvF3PQajvJ+hzBDHCVCmaL1Cgictv 3FXOI9pydjktTggkwhjjTBwUhIXYSok2oA5TXnLx7MaiRzyODqco+bIfgomG67kRxh1WcXkY4l5 7U+YfU7bKF6913JkR7UJFp5wxVLGyckQNPjLhmuDHpF4shGcsqcEv4cY9bvI8LKO2ZhuHhx5v5k mZW1qZC7FGXFngxNBQNNI+ZxVcee6E/R8YFdp2TGA4gcLpTc2H+vUISLuqgvCKt6UJYDKs1g== X-Received: by 2002:a17:90a:e7cc:b0:39d:fe64:5725 with SMTP id 98e67ed59e1d1-39dfe6461f0mr4210211a91.5.1789443058917; Mon, 14 Sep 2026 20:30:58 -0700 (PDT) Received: from gmail.com ([185.220.238.35]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-33ba4f55735sm31317478eec.24.2026.09.14.20.30.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2026 20:30:58 -0700 (PDT) From: Kunwu Chan To: SJ Park Cc: Kunwu Chan , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v2 3/8] mm/damon/core: return an error from damos_commit_filter_arg() Date: Tue, 15 Sep 2026 11:30:49 +0800 Message-ID: <20260915033050.1579457-1-kunwu.chan@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260913171706.103052-4-sj@kernel.org> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Sun, 13 Sep 2026 10:17:00 -0700 SJ Park wrote: > damos_commit_filter_arg() is supposed to always succeed. It may not in > future, for example, if the given filter is invalid. Prepare the case > by modifying its signature to return an error when it failed. Also pipe > the return value to its callers and let them handle the error. > > Signed-off-by: SJ Park > --- > mm/damon/core.c | 41 ++++++++++++++++++++++++++++------------- > 1 file changed, 28 insertions(+), 13 deletions(-) > > diff --git a/mm/damon/core.c b/mm/damon/core.c > index 3d7a973ea8b6f..ea7d8d5a4abf6 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -1317,7 +1317,7 @@ static struct damos_filter *damos_nth_ops_filter(int n, struct damos *s) > return NULL; > } > > -static void damos_commit_filter_arg( > +static int damos_commit_filter_arg( > struct damos_filter *dst, struct damos_filter *src) > { > switch (dst->type) { > @@ -1340,28 +1340,32 @@ static void damos_commit_filter_arg( > default: > break; > } > + return 0; > } > > -static void damos_commit_filter( > +static int damos_commit_filter( > struct damos_filter *dst, struct damos_filter *src) > { > dst->type = src->type; > dst->matching = src->matching; > dst->allow = src->allow; > - damos_commit_filter_arg(dst, src); > + return damos_commit_filter_arg(dst, src); > } > > static int damos_commit_core_filters(struct damos *dst, struct damos *src) > { > struct damos_filter *dst_filter, *next, *src_filter, *new_filter; > - int i = 0, j = 0; > + int i = 0, j = 0, err; > > damos_for_each_core_filter_safe(dst_filter, next, dst) { > src_filter = damos_nth_core_filter(i++, src); > - if (src_filter) > - damos_commit_filter(dst_filter, src_filter); > - else > + if (src_filter) { > + err = damos_commit_filter(dst_filter, src_filter); > + if (err) > + return err; > + } else { > damos_destroy_filter(dst_filter); > + } > } > > damos_for_each_core_filter_safe(src_filter, next, src) { > @@ -1373,7 +1377,11 @@ static int damos_commit_core_filters(struct damos *dst, struct damos *src) > src_filter->allow); > if (!new_filter) > return -ENOMEM; > - damos_commit_filter_arg(new_filter, src_filter); > + err = damos_commit_filter_arg(new_filter, src_filter); > + if (err) { > + damos_destroy_filter(new_filter); > + return err; > + } > damos_add_filter(dst, new_filter); > } > return 0; > @@ -1382,14 +1390,17 @@ static int damos_commit_core_filters(struct damos *dst, struct damos *src) > static int damos_commit_ops_filters(struct damos *dst, struct damos *src) > { > struct damos_filter *dst_filter, *next, *src_filter, *new_filter; > - int i = 0, j = 0; > + int i = 0, j = 0, err; > > damos_for_each_ops_filter_safe(dst_filter, next, dst) { > src_filter = damos_nth_ops_filter(i++, src); > - if (src_filter) > - damos_commit_filter(dst_filter, src_filter); > - else > + if (src_filter) { > + err = damos_commit_filter(dst_filter, src_filter); > + if (err) > + return err; > + } else { > damos_destroy_filter(dst_filter); > + } > } > > damos_for_each_ops_filter_safe(src_filter, next, src) { > @@ -1401,7 +1412,11 @@ static int damos_commit_ops_filters(struct damos *dst, struct damos *src) > src_filter->allow); > if (!new_filter) > return -ENOMEM; > - damos_commit_filter_arg(new_filter, src_filter); > + err = damos_commit_filter_arg(new_filter, src_filter); > + if (err) { > + damos_destroy_filter(new_filter); > + return err; > + } I re-checked this version, and the error return from damos_commit_filter_arg() is now handled at all call sites, including the new-filter paths. Reviewed-by: Kunwu Chan I'll take another look at the remaining patches. Thanks, Kunwu > damos_add_filter(dst, new_filter); > } > return 0; > -- > 2.47.3 > Sent using hkml (https://github.com/sjp38/hackermail)