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. Signed-off-by: Christoph Hellwig <[email protected]> --- lib/raid/xor/xor-core.c | 98 ++++++++++++++++++++--------------------- 1 file changed, 48 insertions(+), 50 deletions(-) diff --git a/lib/raid/xor/xor-core.c b/lib/raid/xor/xor-core.c index 28aa654c288d..a2c529d7b7c2 100644 --- a/lib/raid/xor/xor-core.c +++ b/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 int __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 *tmpl, void *b1, void *b2) 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 *tmpl, void *b1, void *b2) 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_info("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); -- 2.47.3
