From nobody Sat Feb 7 15:16:19 2026 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) (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 0CADA32ED2C for ; Wed, 28 Jan 2026 10:50:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769597433; cv=none; b=LSJ1J0gdNyxDDRMiOClhJCNF5zryVh+OVPhzYcRHCu79/PhYWKuBHkaidO9cQgEiZrAoroaMU70f7vKbRB8NaVaE3pj3+ZkcTrpbpcdM/GjnNUHkn8P0THlVEA/HzZinIKlMKCTUCeD1A/FAwBwOek6xANnwWdd3KSOlxTmy/C8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769597433; c=relaxed/simple; bh=cpWdcgKiC0KPCgrLlg09v6/ScjKw+Tm6Glne/tnTl0s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LoQ87k/MtxqyrIE2wosurWVtsnJQUnpedR2OErlLxd+vQ2sfCRvL9DMnnkPplsUwnZxloFl3tDtVighuCuvqYUuBmV43yxCxEtvSdYa6x6GBYh+DKP3yet2GtmJnnz/DmzY+uGppYLjGfyY3KYx89EQawJw2hmE60+2Y0Ujua6s= 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=RrSj1Dpg; arc=none smtp.client-ip=91.218.175.180 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="RrSj1Dpg" 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=1769597430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mfN+HKIxPojLfnj3CGkpwFshzRxTq1htYY6puasTWyM=; b=RrSj1DpgqEzzvL4v4yOUliunx37UNqEUiw5e1SDoBp6wu9oCaBJZ93T3vBQnMQMKa89CZs NIhvYky1q6TYNZL1U8YJveg5jvmucBfgnuZ9+NZvAlb0J7OYNpXpaey301U1BDXtu1g6W3 eGVCvwBiIj+Yp8Sd03MH1ILwtZk7vbE= From: sunliming@linux.dev To: song@kernel.org, yukuai@fnnas.com Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, sunliming Subject: [PATCH 1/3] lib/raid6: Divide the raid6 algorithm selection process into two parts Date: Wed, 28 Jan 2026 18:49:21 +0800 Message-Id: <20260128104923.338443-2-sunliming@linux.dev> In-Reply-To: <20260128104923.338443-1-sunliming@linux.dev> References: <20260128104923.338443-1-sunliming@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: sunliming Divide the RAID6 algorithm selection process into two parts: fast selection and benchmark selection. To prepare for the asynchronous processing of the benchmark phase. Signed-off-by: sunliming --- lib/raid6/algos.c | 76 +++++++++++++++++++++++++++++++---------------- 1 file changed, 51 insertions(+), 25 deletions(-) diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c index 799e0e5eac26..ac6a77b0ae1d 100644 --- a/lib/raid6/algos.c +++ b/lib/raid6/algos.c @@ -134,7 +134,7 @@ const struct raid6_recov_calls *const raid6_recov_algos= [] =3D { static inline const struct raid6_recov_calls *raid6_choose_recov(void) { const struct raid6_recov_calls *const *algo; - const struct raid6_recov_calls *best; + const struct raid6_recov_calls *best =3D NULL; =20 for (best =3D NULL, algo =3D raid6_recov_algos; *algo; algo++) if (!best || (*algo)->priority > best->priority) @@ -152,24 +152,44 @@ static inline const struct raid6_recov_calls *raid6_c= hoose_recov(void) return best; } =20 -static inline const struct raid6_calls *raid6_choose_gen( - void *(*const dptrs)[RAID6_TEST_DISKS], const int disks) +/* Quick selection: selects the first valid algorithm. */ +static inline const struct raid6_calls *raid6_choose_gen_fast(void) +{ + const struct raid6_calls *const *algo; + const struct raid6_calls *best =3D NULL; + + for (algo =3D raid6_algos; *algo; algo++) { + if ((*algo)->valid && !(*algo)->valid()) + continue; + + best =3D *algo; + break; + } + + if (best) { + raid6_call =3D *best; + pr_info("raid6: skipped pq benchmark and selected %s\n", + best->name); + } else { + pr_err("raid6: No valid algorithm found even for fast selection!\n"); + } + + return best; +} + +static inline const struct raid6_calls *raid6_gen_benchmark( + void *(*const dptrs)[RAID6_TEST_DISKS], const int disks) { unsigned long perf, bestgenperf, j0, j1; int start =3D (disks>>1)-1, stop =3D disks-3; /* work on the second half = of the disks */ const struct raid6_calls *const *algo; - const struct raid6_calls *best; + const struct raid6_calls *best =3D NULL; =20 for (bestgenperf =3D 0, best =3D NULL, algo =3D raid6_algos; *algo; algo+= +) { if (!best || (*algo)->priority >=3D best->priority) { if ((*algo)->valid && !(*algo)->valid()) continue; =20 - if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) { - best =3D *algo; - break; - } - perf =3D 0; =20 preempt_disable(); @@ -200,12 +220,6 @@ static inline const struct raid6_calls *raid6_choose_g= en( =20 raid6_call =3D *best; =20 - if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) { - pr_info("raid6: skipped pq benchmark and selected %s\n", - best->name); - goto out; - } - pr_info("raid6: using algorithm %s gen() %ld MB/s\n", best->name, (bestgenperf * HZ * (disks - 2)) >> @@ -235,16 +249,11 @@ static inline const struct raid6_calls *raid6_choose_= gen( return best; } =20 - /* Try to pick the best algorithm */ /* This code uses the gfmul table as convenient data set to abuse */ - -int __init raid6_select_algo(void) +static int raid6_choose_gen_benmark(const struct raid6_calls **gen_best) { const int disks =3D RAID6_TEST_DISKS; - - const struct raid6_calls *gen_best; - const struct raid6_recov_calls *rec_best; char *disk_ptr, *p; void *dptrs[RAID6_TEST_DISKS]; int i, cycle; @@ -269,14 +278,31 @@ int __init raid6_select_algo(void) if ((disks - 2) * PAGE_SIZE % 65536) memcpy(p, raid6_gfmul, (disks - 2) * PAGE_SIZE % 65536); =20 - /* select raid gen_syndrome function */ - gen_best =3D raid6_choose_gen(&dptrs, disks); + *gen_best =3D raid6_gen_benchmark(&dptrs, disks); + + free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER); + + return 0; +} + +int __init raid6_select_algo(void) +{ + int ret; + const struct raid6_calls *gen_best =3D NULL; + const struct raid6_recov_calls *rec_best =3D NULL; + + /* select raid gen_syndrome functions */ + if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) + gen_best =3D raid6_choose_gen_fast(); + else { + ret =3D raid6_choose_gen_benmark(&gen_best); + if (ret < 0) + return ret; + } =20 /* select raid recover functions */ rec_best =3D raid6_choose_recov(); =20 - free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER); - return gen_best && rec_best ? 0 : -EINVAL; } =20 --=20 2.25.1