From nobody Sat Feb 7 21:14:36 2026 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 3D973157487 for ; Fri, 6 Feb 2026 05:45:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770356720; cv=none; b=nk7aSERRLIO+qPCpZ5gOW/wtkjqW+dQSSktKslZ9eI8h6vqSS8RaS6hYJCKy7Zqod0LWpaWgru9maXJG4kNNxNY4jPhJ8MmbFkiCvKa2a5GFHWONIdvQrwWnxT+JrLyTkL4SZLtHLd49RovsPVLAfVANStP6ygED3la9dHck8GE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770356720; c=relaxed/simple; bh=UHhmAaGZFtWbaHFzFf1XNuxh/+JY3Ape2gWU2P/WYEg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QLU9tMdHjW3y9zlGiMeb8HEAaFgZ5PWQkSn6SOW77tWBAX0xjREvtzc2n1C0e+URR2QH6GFd4E1myoPsKAQJwaTKgJYUwhmlb7GfSMKAjRDQmU4mvoqEWwqVEZ1IfmuDLexN4RAV/WqnTjKLIGil20JFkBqwI0wz3K4uohRpdHI= 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=TKVVkthB; arc=none smtp.client-ip=91.218.175.182 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="TKVVkthB" 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=1770356718; 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=gZgJFlCBgUgfhxW3RQ7XaSw6izc3bNkF4Jlkj/+s0v0=; b=TKVVkthBs9K8PboLNTgnAp9l8uvlqPutgEjQYpGoVNagTIvf+RachBBPvlPfheNp2ebl0M 77PSPWrCLCUUY1HCnZ4B5yNu7uPHG4z9a1FYz5GKpgCWhzP7gJLQtIuAS4aD+yR7hR4NBh 01XPWYxA2Ub4GVE4p2iU2tzI38SfCl0= From: sunliming@linux.dev To: song@kernel.org, yukuai@fnnas.com Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, linan666@huaweicloud.com, sunliming Subject: [PATCH v2 1/3] lib/raid6: Divide the raid6 algorithm selection process into two parts Date: Fri, 6 Feb 2026 13:43:39 +0800 Message-Id: <20260206054341.106878-2-sunliming@linux.dev> In-Reply-To: <20260206054341.106878-1-sunliming@linux.dev> References: <20260206054341.106878-1-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 | 85 +++++++++++++++++++++++++++++++---------------- 1 file changed, 57 insertions(+), 28 deletions(-) diff --git a/lib/raid6/algos.c b/lib/raid6/algos.c index 799e0e5eac26..a14469388b0c 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 +152,43 @@ 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 int raid6_choose_gen_fast(void) +{ + int ret =3D 0; + const struct raid6_calls *const *algo; + const struct raid6_calls *best =3D NULL; + + for (best =3D NULL, algo =3D raid6_algos; *algo; algo++) + if (!best || (*algo)->priority > best->priority) + if (!(*algo)->valid || (*algo)->valid()) + best =3D *algo; + + 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"); + ret =3D -EINVAL; + } + + return ret; +} + +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 +219,6 @@ 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)) >> @@ -230,24 +243,19 @@ static inline const struct raid6_calls *raid6_choose_= gen( (perf * HZ * (disks - 2)) >> (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1)); } - out: 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(void) { 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; + const struct raid6_calls *best =3D NULL; + int i, cycle, ret =3D 0; =20 /* prepare the buffer and fill it circularly with gfmul table */ disk_ptr =3D (char *)__get_free_pages(GFP_KERNEL, RAID6_TEST_DISKS_ORDER); @@ -269,15 +277,36 @@ 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); + best =3D raid6_gen_benchmark(&dptrs, disks); + if (!best) + ret =3D -EINVAL; + + free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER); + + return ret; +} + +int __init raid6_select_algo(void) +{ + int ret =3D 0; + const struct raid6_recov_calls *rec_best =3D NULL; + + /* select raid gen_syndrome functions */ + if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) + ret =3D raid6_choose_gen_fast(); + else + ret =3D raid6_choose_gen_benmark(); + + if (ret < 0) + goto out; =20 /* select raid recover functions */ rec_best =3D raid6_choose_recov(); + if (!rec_best) + ret =3D -EINVAL; =20 - free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER); - - return gen_best && rec_best ? 0 : -EINVAL; +out: + return ret; } =20 static void raid6_exit(void) --=20 2.25.1