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GET /api/patches/2216700/?format=api
{ "id": 2216700, "url": "http://patchwork.ozlabs.org/api/patches/2216700/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-um/patch/20260327061704.3707577-8-hch@lst.de/", "project": { "id": 60, "url": "http://patchwork.ozlabs.org/api/projects/60/?format=api", "name": "User-mode Linux Development", "link_name": "linux-um", "list_id": "linux-um.lists.infradead.org", "list_email": "linux-um@lists.infradead.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260327061704.3707577-8-hch@lst.de>", "list_archive_url": null, "date": "2026-03-27T06:16:39", "name": "[07/28] xor: cleanup registration and probing", "commit_ref": null, "pull_url": null, "state": "not-applicable", "archived": false, "hash": "748f957c5cfcce9daec437fc6a7e309809f417f8", "submitter": { "id": 82, "url": "http://patchwork.ozlabs.org/api/people/82/?format=api", "name": "Christoph Hellwig", "email": "hch@lst.de" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/linux-um/patch/20260327061704.3707577-8-hch@lst.de/mbox/", "series": [ { "id": 497692, "url": "http://patchwork.ozlabs.org/api/series/497692/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linux-um/list/?series=497692", "date": "2026-03-27T06:16:33", "name": "[01/28] xor: assert that xor_blocks is not call from interrupt context", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/497692/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2216700/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2216700/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "\n <linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=lists.infradead.org header.i=@lists.infradead.org\n header.a=rsa-sha256 header.s=bombadil.20210309 header.b=GyX2cb3n;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=none (no SPF record) smtp.mailfrom=lists.infradead.org\n (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org;\n envelope-from=linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from bombadil.infradead.org (bombadil.infradead.org\n [IPv6:2607:7c80:54:3::133])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fhr8H6fdjz1y1j\n\tfor <incoming@patchwork.ozlabs.org>; Fri, 27 Mar 2026 17:19:27 +1100 (AEDT)", "from localhost ([::1] helo=bombadil.infradead.org)\n\tby bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux))\n\tid 1w60XW-00000006lRu-1ifq;\n\tFri, 27 Mar 2026 06:19:26 +0000", "from\n 2a02-8389-2341-5b80-d601-7564-c2e0-491c.cable.dynamic.v6.surfer.at\n ([2a02:8389:2341:5b80:d601:7564:c2e0:491c] helo=localhost)\n\tby bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux))\n\tid 1w60XT-00000006lGc-035D;\n\tFri, 27 Mar 2026 06:19:23 +0000" ], "DKIM-Signature": "v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help\n\t:List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding:\n\tMIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:\n\tReply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From:\n\tResent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner;\n\tbh=jmVHDIGjSVXJ6mznFR3BDf1KydPvvWCTsKbXoXp3DKw=; b=GyX2cb3nkRNrxKPuHn9drOeZ03\n\tTKRbahWPcuacgtGpjQEX2h93r4UCsQIVyhEm5rR4FV0XCMauDA+PkN7VtKiWJOo8dvvtVnGOKmIFi\n\tMvFaze+bkxUvASRUrqibNroEfJsFrQQerVaFxBWOgWMWTXkv09H5offUOwJ68JQ3T6rUYQian6obu\n\tyPzFW5dGI/t9+41UDa3Udwrle6GoXJnXXnmS1TylnjujJzcDhEgpqAFCQYvO5kshIMvljJ3oKKL+6\n\tnRSLMf67hdoVmpHBY/jUv45tWiH+TVtPZAS3JrdDQnDJWP2FNevDWCiECiBq13nR8tVKBmaQCtqwn\n\ttBfxRKZw==;", "From": "Christoph Hellwig <hch@lst.de>", "To": "Andrew Morton <akpm@linux-foundation.org>", "Cc": "Richard Henderson <richard.henderson@linaro.org>,\n\tMatt Turner <mattst88@gmail.com>,\n\tMagnus Lindholm <linmag7@gmail.com>,\n\tRussell King <linux@armlinux.org.uk>,\n\tCatalin Marinas <catalin.marinas@arm.com>,\n\tWill Deacon <will@kernel.org>,\n\tArd Biesheuvel <ardb@kernel.org>,\n\tHuacai Chen <chenhuacai@kernel.org>,\n\tWANG Xuerui <kernel@xen0n.name>,\n\tMadhavan Srinivasan <maddy@linux.ibm.com>,\n\tMichael Ellerman <mpe@ellerman.id.au>,\n\tNicholas Piggin <npiggin@gmail.com>,\n\t\"Christophe Leroy (CS GROUP)\" <chleroy@kernel.org>,\n\tPaul Walmsley <pjw@kernel.org>,\n\tPalmer Dabbelt <palmer@dabbelt.com>,\n\tAlbert Ou <aou@eecs.berkeley.edu>,\n\tAlexandre Ghiti <alex@ghiti.fr>,\n\tHeiko Carstens <hca@linux.ibm.com>,\n\tVasily Gorbik <gor@linux.ibm.com>,\n\tAlexander Gordeev <agordeev@linux.ibm.com>,\n\tChristian Borntraeger <borntraeger@linux.ibm.com>,\n\tSven Schnelle <svens@linux.ibm.com>,\n\t\"David S. Miller\" <davem@davemloft.net>,\n\tAndreas Larsson <andreas@gaisler.com>,\n\tRichard Weinberger <richard@nod.at>,\n\tAnton Ivanov <anton.ivanov@cambridgegreys.com>,\n\tJohannes Berg <johannes@sipsolutions.net>,\n\tThomas Gleixner <tglx@kernel.org>,\n\tIngo Molnar <mingo@redhat.com>,\n\tBorislav Petkov <bp@alien8.de>,\n\tDave Hansen <dave.hansen@linux.intel.com>,\n\tx86@kernel.org,\n\t\"H. Peter Anvin\" <hpa@zytor.com>,\n\tHerbert Xu <herbert@gondor.apana.org.au>,\n\tDan Williams <dan.j.williams@intel.com>,\n\tChris Mason <clm@fb.com>,\n\tDavid Sterba <dsterba@suse.com>,\n\tArnd Bergmann <arnd@arndb.de>,\n\tSong Liu <song@kernel.org>,\n\tYu Kuai <yukuai@fnnas.com>,\n\tLi Nan <linan122@huawei.com>,\n\t\"Theodore Ts'o\" <tytso@mit.edu>,\n\t\"Jason A. Donenfeld\" <Jason@zx2c4.com>,\n\tlinux-alpha@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org,\n\tlinux-arm-kernel@lists.infradead.org,\n\tloongarch@lists.linux.dev,\n\tlinuxppc-dev@lists.ozlabs.org,\n\tlinux-riscv@lists.infradead.org,\n\tlinux-s390@vger.kernel.org,\n\tsparclinux@vger.kernel.org,\n\tlinux-um@lists.infradead.org,\n\tlinux-crypto@vger.kernel.org,\n\tlinux-btrfs@vger.kernel.org,\n\tlinux-arch@vger.kernel.org,\n\tlinux-raid@vger.kernel.org", "Subject": "[PATCH 07/28] xor: cleanup registration and probing", "Date": "Fri, 27 Mar 2026 07:16:39 +0100", "Message-ID": "<20260327061704.3707577-8-hch@lst.de>", "X-Mailer": "git-send-email 2.47.3", "In-Reply-To": "<20260327061704.3707577-1-hch@lst.de>", "References": "<20260327061704.3707577-1-hch@lst.de>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-BeenThere": "linux-um@lists.infradead.org", "X-Mailman-Version": "2.1.34", "Precedence": "list", "List-Id": "<linux-um.lists.infradead.org>", "List-Unsubscribe": "<http://lists.infradead.org/mailman/options/linux-um>,\n <mailto:linux-um-request@lists.infradead.org?subject=unsubscribe>", "List-Archive": "<http://lists.infradead.org/pipermail/linux-um/>", "List-Post": "<mailto:linux-um@lists.infradead.org>", "List-Help": "<mailto:linux-um-request@lists.infradead.org?subject=help>", "List-Subscribe": "<http://lists.infradead.org/mailman/listinfo/linux-um>,\n <mailto:linux-um-request@lists.infradead.org?subject=subscribe>", "Sender": "\"linux-um\" <linux-um-bounces@lists.infradead.org>", "Errors-To": "linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org" }, "content": "Originally, the XOR code benchmarked all algorithms at load time, but\nit has since then been hacked multiple times to allow forcing an\nalgorithm, and then commit 524ccdbdfb52 (\"crypto: xor - defer load time\nbenchmark to a later time\") changed the logic to a two-step process\nor registration and benchmarking, but only when built-in.\n\nRework this, so that the XOR_TRY_TEMPLATES macro magic now always just\ndeals with adding the templates to the list, and benchmarking is always\ndone in a second pass; for modular builds from module_init, and for the\nbuilt-in case using a separate init call level.\n\nSigned-off-by: Christoph Hellwig <hch@lst.de>\n---\n lib/raid/xor/xor-core.c | 98 ++++++++++++++++++++---------------------\n 1 file changed, 48 insertions(+), 50 deletions(-)", "diff": "diff --git a/lib/raid/xor/xor-core.c b/lib/raid/xor/xor-core.c\nindex c54f48405c40..e6e593e404fb 100644\n--- a/lib/raid/xor/xor-core.c\n+++ b/lib/raid/xor/xor-core.c\n@@ -52,29 +52,14 @@ EXPORT_SYMBOL(xor_blocks);\n \n /* Set of all registered templates. */\n static struct xor_block_template *__initdata template_list;\n+static bool __initdata xor_forced = false;\n \n-#ifndef MODULE\n static void __init do_xor_register(struct xor_block_template *tmpl)\n {\n \ttmpl->next = template_list;\n \ttemplate_list = tmpl;\n }\n \n-static int __init register_xor_blocks(void)\n-{\n-\tactive_template = XOR_SELECT_TEMPLATE(NULL);\n-\n-\tif (!active_template) {\n-#define xor_speed\tdo_xor_register\n-\t\t// register all the templates and pick the first as the default\n-\t\tXOR_TRY_TEMPLATES;\n-#undef xor_speed\n-\t\tactive_template = template_list;\n-\t}\n-\treturn 0;\n-}\n-#endif\n-\n #define BENCH_SIZE\t4096\n #define REPS\t\t800U\n \n@@ -85,9 +70,6 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)\n \tunsigned long reps;\n \tktime_t min, start, t0;\n \n-\ttmpl->next = template_list;\n-\ttemplate_list = tmpl;\n-\n \tpreempt_disable();\n \n \treps = 0;\n@@ -111,63 +93,79 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)\n \tpr_info(\" %-16s: %5d MB/sec\\n\", tmpl->name, speed);\n }\n \n-static int __init\n-calibrate_xor_blocks(void)\n+static int __init calibrate_xor_blocks(void)\n {\n \tvoid *b1, *b2;\n \tstruct xor_block_template *f, *fastest;\n \n-\tfastest = XOR_SELECT_TEMPLATE(NULL);\n-\n-\tif (fastest) {\n-\t\tprintk(KERN_INFO \"xor: automatically using best \"\n-\t\t\t\t \"checksumming function %-10s\\n\",\n-\t\t fastest->name);\n-\t\tgoto out;\n-\t}\n+\tif (xor_forced)\n+\t\treturn 0;\n \n \tb1 = (void *) __get_free_pages(GFP_KERNEL, 2);\n \tif (!b1) {\n-\t\tprintk(KERN_WARNING \"xor: Yikes! No memory available.\\n\");\n+\t\tpr_warn(\"xor: Yikes! No memory available.\\n\");\n \t\treturn -ENOMEM;\n \t}\n \tb2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;\n \n-\t/*\n-\t * If this arch/cpu has a short-circuited selection, don't loop through\n-\t * all the possible functions, just test the best one\n-\t */\n-\n-#define xor_speed(templ)\tdo_xor_speed((templ), b1, b2)\n-\n-\tprintk(KERN_INFO \"xor: measuring software checksum speed\\n\");\n-\ttemplate_list = NULL;\n-\tXOR_TRY_TEMPLATES;\n+\tpr_info(\"xor: measuring software checksum speed\\n\");\n \tfastest = template_list;\n-\tfor (f = fastest; f; f = f->next)\n+\tfor (f = template_list; f; f = f->next) {\n+\t\tdo_xor_speed(f, b1, b2);\n \t\tif (f->speed > fastest->speed)\n \t\t\tfastest = f;\n-\n+\t}\n+\tactive_template = fastest;\n \tpr_info(\"xor: using function: %s (%d MB/sec)\\n\",\n \t fastest->name, fastest->speed);\n \n+\tfree_pages((unsigned long)b1, 2);\n+\treturn 0;\n+}\n+\n+static int __init xor_init(void)\n+{\n+\t/*\n+\t * If this arch/cpu has a short-circuited selection, don't loop through\n+\t * all the possible functions, just use the best one.\n+\t */\n+\tactive_template = XOR_SELECT_TEMPLATE(NULL);\n+\tif (active_template) {\n+\t\tpr_info(\"xor: automatically using best checksumming function %-10s\\n\",\n+\t\t\tactive_template->name);\n+\t\txor_forced = true;\n+\t\treturn 0;\n+\t}\n+\n+#define xor_speed\tdo_xor_register\n+\tXOR_TRY_TEMPLATES;\n #undef xor_speed\n \n-\tfree_pages((unsigned long)b1, 2);\n-out:\n-\tactive_template = fastest;\n+#ifdef MODULE\n+\treturn calibrate_xor_blocks();\n+#else\n+\t/*\n+\t * Pick the first template as the temporary default until calibration\n+\t * happens.\n+\t */\n+\tactive_template = template_list;\n \treturn 0;\n+#endif\n }\n \n-static __exit void xor_exit(void) { }\n+static __exit void xor_exit(void)\n+{\n+}\n \n MODULE_DESCRIPTION(\"RAID-5 checksumming functions\");\n MODULE_LICENSE(\"GPL\");\n \n+/*\n+ * When built-in we must register the default template before md, but we don't\n+ * want calibration to run that early as that would delay the boot process.\n+ */\n #ifndef MODULE\n-/* when built-in xor.o must initialize before drivers/md/md.o */\n-core_initcall(register_xor_blocks);\n+__initcall(calibrate_xor_blocks);\n #endif\n-\n-module_init(calibrate_xor_blocks);\n+core_initcall(xor_init);\n module_exit(xor_exit);\n", "prefixes": [ "07/28" ] }