[PATCH] crypto/xor: skip speed test if the xor function is selected automatically
From: Martin Schwidefsky <hidden>
Date: 2016-08-19 12:19:50
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
If the architecture selected the xor function with XOR_SELECT_TEMPLATE the speed result of the do_xor_speed benchmark is of limited value. The speed measurement increases the bootup time a little, which can makes a difference for kernels used in container like virtual machines. Signed-off-by: Martin Schwidefsky <redacted> --- crypto/xor.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-)
diff --git a/crypto/xor.c b/crypto/xor.c
index 35d6b3a..b8975d9 100644
--- a/crypto/xor.c
+++ b/crypto/xor.c@@ -109,6 +109,18 @@ calibrate_xor_blocks(void) void *b1, *b2; struct xor_block_template *f, *fastest; + fastest = NULL; + +#ifdef XOR_SELECT_TEMPLATE + fastest = XOR_SELECT_TEMPLATE(fastest); + if (fastest) { + printk(KERN_INFO "xor: automatically using best " + "checksumming function %-10s\n", + fastest->name); + goto out; + } +#endif + /* * Note: Since the memory is not actually used for _anything_ but to * test the XOR speed, we don't really want kmemcheck to warn about
@@ -126,36 +138,22 @@ calibrate_xor_blocks(void) * all the possible functions, just test the best one */ - fastest = NULL; - -#ifdef XOR_SELECT_TEMPLATE - fastest = XOR_SELECT_TEMPLATE(fastest); -#endif - #define xor_speed(templ) do_xor_speed((templ), b1, b2) - if (fastest) { - printk(KERN_INFO "xor: automatically using best " - "checksumming function:\n"); - xor_speed(fastest); - goto out; - } else { - printk(KERN_INFO "xor: measuring software checksum speed\n"); - XOR_TRY_TEMPLATES; - fastest = template_list; - for (f = fastest; f; f = f->next) - if (f->speed > fastest->speed) - fastest = f; - } + printk(KERN_INFO "xor: measuring software checksum speed\n"); + XOR_TRY_TEMPLATES; + fastest = template_list; + for (f = fastest; f; f = f->next) + if (f->speed > fastest->speed) + fastest = f; printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n", fastest->name, fastest->speed / 1000, fastest->speed % 1000); #undef xor_speed - out: free_pages((unsigned long)b1, 2); - +out: active_template = fastest; return 0; }
--
1.9.1