From: Jens Axboe <jaxboe@fusionio.com>
Date: Mon, 21 Jun 2010 13:08:17 +0000 (+0200)
Subject: Auto-detect missing hw support for crc32c and fallback to software
X-Git-Tag: fio-1.41.3~3
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=5d7c5d348d66794fd5e8aa3090f582358e6c5017;p=fio.git

Auto-detect missing hw support for crc32c and fallback to software

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---

diff --git a/crc/crc32c-intel.c b/crc/crc32c-intel.c
index cec5ad5d..fc106fa5 100644
--- a/crc/crc32c-intel.c
+++ b/crc/crc32c-intel.c
@@ -1,4 +1,10 @@
 #include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 #include "crc32c.h"
 
 /*
@@ -68,5 +74,37 @@ uint32_t crc32c_intel(unsigned char const *data, unsigned long length)
 	return crc;
 }
 
-#endif /* ARCH_HAVE_SSE */
+static void sig_ill(int sig)
+{
+}
+
+static void crc32c_test(void)
+{
+	unsigned char buf[4] = { 1, 2, 3, 4 };
+	struct sigaction act;
+
+	/*
+	 * Check if hw accelerated crc32c is available
+	 */
+	memset(&act, 0, sizeof(act));
+	act.sa_handler = sig_ill;
+	act.sa_flags = SA_RESETHAND;
+	sigaction(SIGILL, &act, NULL);
+
+	(void) crc32c_intel(buf, sizeof(buf));
+}
+
+int crc32c_intel_works(void)
+{
+	if (!fork()) {
+		crc32c_test();
+		exit(0);
+	} else {
+		int status;
 
+		wait(&status);
+		return !WIFSIGNALED(status);
+	}
+}
+
+#endif /* ARCH_HAVE_SSE */
diff --git a/crc/crc32c.h b/crc/crc32c.h
index 0976261a..50f3665f 100644
--- a/crc/crc32c.h
+++ b/crc/crc32c.h
@@ -24,8 +24,13 @@ extern uint32_t crc32c(unsigned char const *, unsigned long);
 
 #ifdef ARCH_HAVE_SSE
 extern uint32_t crc32c_intel(unsigned char const *, unsigned long);
+extern int crc32c_intel_works(void);
 #else
 #define crc32c_intel crc32c
+static inline int crc32c_intel_works(void)
+{
+	return 0;
+}
 #endif
 
 #endif
diff --git a/fio.c b/fio.c
index 4d260600..b2a08bf0 100644
--- a/fio.c
+++ b/fio.c
@@ -142,15 +142,6 @@ static void sig_int(int sig)
 	}
 }
 
-static void sig_ill(int fio_unused sig)
-{
-	if (!threads)
-		return;
-
-	log_err("fio: system does not support the sse4.2 instruction for crc32c-intel.\nUse crc32c instead.\n");
-	terminate_threads(TERMINATE_ALL);
-}
-
 static void set_sig_handlers(void)
 {
 	struct sigaction act;
@@ -165,11 +156,6 @@ static void set_sig_handlers(void)
 	act.sa_flags = SA_RESTART;
 	sigaction(SIGINT, &act, NULL);
 
-	memset(&act, 0, sizeof(act));
-	act.sa_handler = sig_ill;
-	act.sa_flags = SA_RESETHAND;
-	sigaction(SIGILL, &act, NULL);
-
 	memset(&act, 0, sizeof(act));
 	act.sa_handler = sig_quit;
 	act.sa_flags = SA_RESTART;
diff --git a/options.c b/options.c
index f470b453..fb187489 100644
--- a/options.c
+++ b/options.c
@@ -16,6 +16,8 @@
 #include "lib/fls.h"
 #include "options.h"
 
+#include "crc/crc32c.h"
+
 /*
  * Check if mmap/mmaphuge has a :/foo/bar/file at the end. If so, return that.
  */
@@ -225,6 +227,21 @@ static int str_mem_cb(void *data, const char *mem)
 	return 0;
 }
 
+static int str_verify_cb(void *data, const char *mem)
+{
+	struct thread_data *td = data;
+
+	if (td->o.verify != VERIFY_CRC32C_INTEL)
+		return 0;
+
+	if (!crc32c_intel_works()) {
+		log_info("fio: System does not support hw accelerated crc32c. Falling back to sw crc32c.\n");
+		td->o.verify = VERIFY_CRC32C;
+	}
+
+	return 0;
+}
+
 static int fio_clock_source_cb(void *data, const char *str)
 {
 	struct thread_data *td = data;
@@ -1298,6 +1315,7 @@ static struct fio_option options[FIO_MAX_OPTS] = {
 		.type	= FIO_OPT_STR,
 		.off1	= td_var_offset(verify),
 		.help	= "Verify data written",
+		.cb	= str_verify_cb,
 		.def	= "0",
 		.posval = {
 			  { .ival = "0",