[dpdk-dev,v7,02/14] eal: do not panic when CPU isn't supported
diff mbox

Message ID 20170322201940.24028-3-aconole@redhat.com
State Accepted, archived
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Context Check Description
ci/Intel-compilation fail Compilation issues
ci/checkpatch success coding style OK

Commit Message

Aaron Conole March 22, 2017, 8:19 p.m. UTC
This adds a new API to check for the eal cpu versions.

It's now possible to gracefully exit the application, or for
applications which support non-dpdk datapaths working in concert with
DPDK datapaths, there no longer is the possibility of exiting for
unsupported CPUs.

Signed-off-by: Aaron Conole <aconole@redhat.com>
---
 lib/librte_eal/bsdapp/eal/eal.c                      |  6 +++++-
 lib/librte_eal/common/eal_common_cpuflags.c          | 13 +++++++++++--
 lib/librte_eal/common/include/generic/rte_cpuflags.h |  9 +++++++++
 lib/librte_eal/linuxapp/eal/eal.c                    |  6 +++++-
 4 files changed, 30 insertions(+), 4 deletions(-)

Comments

Bruce Richardson March 23, 2017, 1:47 p.m. UTC | #1
On Wed, Mar 22, 2017 at 04:19:28PM -0400, Aaron Conole wrote:
> This adds a new API to check for the eal cpu versions.
> 
> It's now possible to gracefully exit the application, or for
> applications which support non-dpdk datapaths working in concert with
> DPDK datapaths, there no longer is the possibility of exiting for
> unsupported CPUs.
> 
> Signed-off-by: Aaron Conole <aconole@redhat.com>

I think we should mark the old function as deprecated or else delete it
entirely. It was technically public, but I suspect it was only ever used
by the EAL init, so I'd look to get rid of it ASAP rather than leave it
hanging around unneeded.

/Bruce
Aaron Conole March 23, 2017, 2:27 p.m. UTC | #2
Bruce Richardson <bruce.richardson@intel.com> writes:

> On Wed, Mar 22, 2017 at 04:19:28PM -0400, Aaron Conole wrote:
>> This adds a new API to check for the eal cpu versions.
>> 
>> It's now possible to gracefully exit the application, or for
>> applications which support non-dpdk datapaths working in concert with
>> DPDK datapaths, there no longer is the possibility of exiting for
>> unsupported CPUs.
>> 
>> Signed-off-by: Aaron Conole <aconole@redhat.com>
>
> I think we should mark the old function as deprecated or else delete it
> entirely. It was technically public, but I suspect it was only ever used
> by the EAL init, so I'd look to get rid of it ASAP rather than leave it
> hanging around unneeded.

Okay, I'll submit a follow on patch after this is accepted to mark it as
deprecated.  I agree, I don't know of any application using it (though I
looked at MoonGen, ovs, and warp17).

> /Bruce

Patch
diff mbox

diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
index 12df127..8ad6157 100644
--- a/lib/librte_eal/bsdapp/eal/eal.c
+++ b/lib/librte_eal/bsdapp/eal/eal.c
@@ -505,7 +505,11 @@  rte_eal_init(int argc, char **argv)
 	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 
 	/* checks if the machine is adequate */
-	rte_cpu_check_supported();
+	if (!rte_cpu_is_supported()) {
+		rte_eal_init_alert("unsupported cpu type.");
+		rte_errno = ENOTSUP;
+		return -1;
+	}
 
 	if (!rte_atomic32_test_and_set(&run_once))
 		return -1;
diff --git a/lib/librte_eal/common/eal_common_cpuflags.c b/lib/librte_eal/common/eal_common_cpuflags.c
index b5f76f7..9a2d080 100644
--- a/lib/librte_eal/common/eal_common_cpuflags.c
+++ b/lib/librte_eal/common/eal_common_cpuflags.c
@@ -43,6 +43,13 @@ 
 void
 rte_cpu_check_supported(void)
 {
+	if (!rte_cpu_is_supported())
+		exit(1);
+}
+
+int
+rte_cpu_is_supported(void)
+{
 	/* This is generated at compile-time by the build system */
 	static const enum rte_cpu_flag_t compile_time_flags[] = {
 			RTE_COMPILE_TIME_CPUFLAGS
@@ -57,14 +64,16 @@  rte_cpu_check_supported(void)
 			fprintf(stderr,
 				"ERROR: CPU feature flag lookup failed with error %d\n",
 				ret);
-			exit(1);
+			return 0;
 		}
 		if (!ret) {
 			fprintf(stderr,
 			        "ERROR: This system does not support \"%s\".\n"
 			        "Please check that RTE_MACHINE is set correctly.\n",
 			        rte_cpu_get_flag_name(compile_time_flags[i]));
-			exit(1);
+			return 0;
 		}
 	}
+
+	return 1;
 }
diff --git a/lib/librte_eal/common/include/generic/rte_cpuflags.h b/lib/librte_eal/common/include/generic/rte_cpuflags.h
index 71321f3..f01624d 100644
--- a/lib/librte_eal/common/include/generic/rte_cpuflags.h
+++ b/lib/librte_eal/common/include/generic/rte_cpuflags.h
@@ -82,4 +82,13 @@  rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature);
 void
 rte_cpu_check_supported(void);
 
+/**
+ * This function checks that the currently used CPU supports the CPU features
+ * that were specified at compile time. It is called automatically within the
+ * EAL, so does not need to be used by applications.  This version returns a
+ * result so that decisions may be made (for instance, graceful shutdowns).
+ */
+int
+rte_cpu_is_supported(void);
+
 #endif /* _RTE_CPUFLAGS_H_ */
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 81692e7..67e4c6f 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -759,7 +759,11 @@  rte_eal_init(int argc, char **argv)
 	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 
 	/* checks if the machine is adequate */
-	rte_cpu_check_supported();
+	if (!rte_cpu_is_supported()) {
+		rte_eal_init_alert("unsupported cpu type.");
+		rte_errno = ENOTSUP;
+		return -1;
+	}
 
 	if (!rte_atomic32_test_and_set(&run_once))
 		return -1;