From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D65FE3750A4 for ; Fri, 27 Mar 2026 17:49:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774633782; cv=none; b=XatsewjSSzsoMyIAcFzh1kgnX1akhLjH+VSVUVtXnloNJOSSgyOhPIo8FZgFb8E/j7/iWFQhy7dgCZqLQ5A2kBhH0y/i2Alq0mSLFBksC/3vmDhqz2tjgBsvh9qoKCyYkdq3GjYva/atfQfHj9mTG0WfH6f8Y7wytBQm6qNMYAo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774633782; c=relaxed/simple; bh=8dOJaYlWd3kXdyCvJKo+rPsq2Awpx9WNWdWJA8xdVyU=; h=Date:To:From:Subject:Message-Id; b=Yu49ua18XuRxKUy9LmScstBHH2+g+nRZJ0VI6mL4uDtTHymaGOvy6kIn1dI/2xAz1yh0kQWvB0fjEozI9/0VJHRLivjF1BFbzUQynM/3q7ebTGlZw4yiZC8dMoS8krGuUTM9GgwXeaI01bhWFYYyWswADXsfOIRi/nrK0N049lI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=meZH8JB6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="meZH8JB6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EF2CC19423; Fri, 27 Mar 2026 17:49:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774633782; bh=8dOJaYlWd3kXdyCvJKo+rPsq2Awpx9WNWdWJA8xdVyU=; h=Date:To:From:Subject:From; b=meZH8JB6Tv1BeyI82BUQvPdNBTgJHppnh4WKQ4MKunQEpApIjGCbrbn1MLg+YyXSR MKaFbcr6Z6nkeeepy/ilQewXfLk1hsQcrbbnm8NiR76RljAVE28apxSmOMrxOtyhO0 P9A3nUIXBVBl5hbKzjWQEaHRhEzb0XnXeNLNonjY= Date: Fri, 27 Mar 2026 10:49:41 -0700 To: mm-commits@vger.kernel.org,hch@lst.de,akpm@linux-foundation.org From: Andrew Morton Subject: + xor-cleanup-registration-and-probing.patch added to mm-nonmm-unstable branch Message-Id: <20260327174942.6EF2CC19423@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: xor: cleanup registration and probing has been added to the -mm mm-nonmm-unstable branch. Its filename is xor-cleanup-registration-and-probing.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/xor-cleanup-registration-and-probing.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Christoph Hellwig Subject: xor: cleanup registration and probing Date: Fri, 27 Mar 2026 07:16:39 +0100 Originally, the XOR code benchmarked all algorithms at load time, but it has since then been hacked multiple times to allow forcing an algorithm, and then commit 524ccdbdfb52 ("crypto: xor - defer load time benchmark to a later time") changed the logic to a two-step process or registration and benchmarking, but only when built-in. Rework this, so that the XOR_TRY_TEMPLATES macro magic now always just deals with adding the templates to the list, and benchmarking is always done in a second pass; for modular builds from module_init, and for the built-in case using a separate init call level. Link: https://lkml.kernel.org/r/20260327061704.3707577-8-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Andreas Larsson Cc: Anton Ivanov Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: "Borislav Petkov (AMD)" Cc: Catalin Marinas Cc: Chris Mason Cc: Christian Borntraeger Cc: Dan Williams Cc: David S. Miller Cc: David Sterba Cc: Heiko Carstens Cc: Herbert Xu Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Jason A. Donenfeld Cc: Johannes Berg Cc: Li Nan Cc: Madhavan Srinivasan Cc: Magnus Lindholm Cc: Matt Turner Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Richard Henderson Cc: Richard Weinberger Cc: Russell King Cc: Song Liu Cc: Sven Schnelle Cc: Ted Ts'o Cc: Vasily Gorbik Cc: WANG Xuerui Cc: Will Deacon Signed-off-by: Andrew Morton --- lib/raid/xor/xor-core.c | 98 ++++++++++++++++++-------------------- 1 file changed, 48 insertions(+), 50 deletions(-) --- a/lib/raid/xor/xor-core.c~xor-cleanup-registration-and-probing +++ a/lib/raid/xor/xor-core.c @@ -52,29 +52,14 @@ EXPORT_SYMBOL(xor_blocks); /* Set of all registered templates. */ static struct xor_block_template *__initdata template_list; +static bool __initdata xor_forced = false; -#ifndef MODULE static void __init do_xor_register(struct xor_block_template *tmpl) { tmpl->next = template_list; template_list = tmpl; } -static int __init register_xor_blocks(void) -{ - active_template = XOR_SELECT_TEMPLATE(NULL); - - if (!active_template) { -#define xor_speed do_xor_register - // register all the templates and pick the first as the default - XOR_TRY_TEMPLATES; -#undef xor_speed - active_template = template_list; - } - return 0; -} -#endif - #define BENCH_SIZE 4096 #define REPS 800U @@ -85,9 +70,6 @@ do_xor_speed(struct xor_block_template * unsigned long reps; ktime_t min, start, t0; - tmpl->next = template_list; - template_list = tmpl; - preempt_disable(); reps = 0; @@ -111,63 +93,79 @@ do_xor_speed(struct xor_block_template * pr_info(" %-16s: %5d MB/sec\n", tmpl->name, speed); } -static int __init -calibrate_xor_blocks(void) +static int __init calibrate_xor_blocks(void) { void *b1, *b2; struct xor_block_template *f, *fastest; - fastest = XOR_SELECT_TEMPLATE(NULL); - - if (fastest) { - printk(KERN_INFO "xor: automatically using best " - "checksumming function %-10s\n", - fastest->name); - goto out; - } + if (xor_forced) + return 0; b1 = (void *) __get_free_pages(GFP_KERNEL, 2); if (!b1) { - printk(KERN_WARNING "xor: Yikes! No memory available.\n"); + pr_warn("xor: Yikes! No memory available.\n"); return -ENOMEM; } b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE; - /* - * If this arch/cpu has a short-circuited selection, don't loop through - * all the possible functions, just test the best one - */ - -#define xor_speed(templ) do_xor_speed((templ), b1, b2) - - printk(KERN_INFO "xor: measuring software checksum speed\n"); - template_list = NULL; - XOR_TRY_TEMPLATES; + pr_info("xor: measuring software checksum speed\n"); fastest = template_list; - for (f = fastest; f; f = f->next) + for (f = template_list; f; f = f->next) { + do_xor_speed(f, b1, b2); if (f->speed > fastest->speed) fastest = f; - + } + active_template = fastest; pr_info("xor: using function: %s (%d MB/sec)\n", fastest->name, fastest->speed); + free_pages((unsigned long)b1, 2); + return 0; +} + +static int __init xor_init(void) +{ + /* + * If this arch/cpu has a short-circuited selection, don't loop through + * all the possible functions, just use the best one. + */ + active_template = XOR_SELECT_TEMPLATE(NULL); + if (active_template) { + pr_info("xor: automatically using best checksumming function %-10s\n", + active_template->name); + xor_forced = true; + return 0; + } + +#define xor_speed do_xor_register + XOR_TRY_TEMPLATES; #undef xor_speed - free_pages((unsigned long)b1, 2); -out: - active_template = fastest; +#ifdef MODULE + return calibrate_xor_blocks(); +#else + /* + * Pick the first template as the temporary default until calibration + * happens. + */ + active_template = template_list; return 0; +#endif } -static __exit void xor_exit(void) { } +static __exit void xor_exit(void) +{ +} MODULE_DESCRIPTION("RAID-5 checksumming functions"); MODULE_LICENSE("GPL"); +/* + * When built-in we must register the default template before md, but we don't + * want calibration to run that early as that would delay the boot process. + */ #ifndef MODULE -/* when built-in xor.o must initialize before drivers/md/md.o */ -core_initcall(register_xor_blocks); +__initcall(calibrate_xor_blocks); #endif - -module_init(calibrate_xor_blocks); +core_initcall(xor_init); module_exit(xor_exit); _ Patches currently in -mm which might be from hch@lst.de are xor-assert-that-xor_blocks-is-not-call-from-interrupt-context.patch arm-xor-remove-in_interrupt-handling.patch arm64-xor-fix-conflicting-attributes-for-xor_block_template.patch um-xor-cleanup-xorh.patch xor-move-to-lib-raid.patch xor-small-cleanups.patch xor-cleanup-registration-and-probing.patch xor-split-xorh.patch xor-remove-macro-abuse-for-xor-implementation-registrations.patch xor-move-generic-implementations-out-of-asm-generic-xorh.patch alpha-move-the-xor-code-to-lib-raid.patch arm-move-the-xor-code-to-lib-raid.patch arm64-move-the-xor-code-to-lib-raid.patch loongarch-move-the-xor-code-to-lib-raid.patch powerpc-move-the-xor-code-to-lib-raid.patch riscv-move-the-xor-code-to-lib-raid.patch sparc-move-the-xor-code-to-lib-raid.patch s390-move-the-xor-code-to-lib-raid.patch x86-move-the-xor-code-to-lib-raid.patch xor-avoid-indirect-calls-for-arm64-optimized-ops.patch xor-make-xorko-self-contained-in-lib-raid.patch xor-add-a-better-public-api.patch xor-add-a-better-public-api-2.patch async_xor-use-xor_gen.patch btrfs-use-xor_gen.patch xor-pass-the-entire-operation-to-the-low-level-ops.patch xor-use-static_call-for-xor_gen.patch xor-add-a-kunit-test-case.patch