[dpdk-dev] [PATCH v3 2/2] eal: add additional info if core mask too long

[David Hunt <david.hunt@intel.com>]

If the user requests to use an lcore above 128 using -c,
the eal will exit with "EAL: invalid core list syntax" and
very little else useful information.

This patch adds some extra information suggesting to use --lcores
so that physical cores above RTE_MAX_LCORE (default 128) can be
used. This is achieved by using the --lcores option by mapping
the logical cores in the application to physical cores.

There is no change in functionalty, just additional messages
suggesting how the --lcores option might be used for the supplied
list of lcores. For example, if
"-c 0xf00000000000000000000000000000000" is used, we see the
following additional output on the command line:

EAL: Error = One of the 4 cores provided exceeds RTE_MAX_LCORE (128)
EAL: Please use --lcores instead, e.g. --lcores 0@128,1@129,2@130,3@131

Signed-off-by: David Hunt <david.hunt@intel.com>

---
changes in v3
   * added this patch to the set. Addresses the changes for
     the -c option.
---
 lib/eal/common/eal_common_options.c | 67 +++++++++++++++++++++++------
 1 file changed, 55 insertions(+), 12 deletions(-)

diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
index 6139b2b21e..331dca1e38 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -753,15 +753,25 @@ check_core_list(int *lcores, unsigned int count)
 static int
 eal_parse_coremask(const char *coremask, int *cores)
 {
-	unsigned count = 0;
+	unsigned int count = 0, k;
 	int i, j, idx;
 	int val;
 	char c;
+	int lcores[RTE_MAX_LCORE];
+	char *coremask_copy = NULL;
 
 	for (idx = 0; idx < RTE_MAX_LCORE; idx++)
 		cores[idx] = -1;
 	idx = 0;
 
+	coremask_copy = calloc(1, strlen(coremask)+1);
+	if (coremask_copy == NULL) {
+		RTE_LOG(ERR, EAL, "Unable to allocate coremask copy\n");
+		return -ENOMEM;
+	}
+
+	strlcpy(coremask_copy, coremask, strlen(coremask)+1);
+
 	/* Remove all blank characters ahead and after .
 	 * Remove 0x/0X if exists.
 	 */
@@ -773,30 +783,63 @@ eal_parse_coremask(const char *coremask, int *cores)
 	i = strlen(coremask);
 	while ((i > 0) && isblank(coremask[i - 1]))
 		i--;
-	if (i == 0)
-		return -1;
+	if (i == 0) {
+		RTE_LOG(ERR, EAL, "No lcores in coremask: %s\n", coremask_copy);
+		goto err;
+	}
 
-	for (i = i - 1; i >= 0 && idx < RTE_MAX_LCORE; i--) {
+	for (i = i - 1; i >= 0; i--) {
 		c = coremask[i];
 		if (isxdigit(c) == 0) {
 			/* invalid characters */
-			return -1;
+			RTE_LOG(ERR, EAL, "invalid characters in coremask: %s\n",
+					coremask_copy);
+			goto err;
 		}
 		val = xdigit2val(c);
-		for (j = 0; j < BITS_PER_HEX && idx < RTE_MAX_LCORE; j++, idx++)
+		for (j = 0; j < BITS_PER_HEX; j++, idx++)
 		{
 			if ((1 << j) & val) {
-				cores[idx] = count;
-				count++;
+				lcores[count++] = idx;
+				if (count > RTE_MAX_LCORE) {
+					RTE_LOG(ERR, EAL, "Too many lcores provided. Cannot exceed %d\n",
+							RTE_MAX_LCORE);
+					goto err;
+				}
 			}
 		}
 	}
 	for (; i >= 0; i--)
-		if (coremask[i] != '0')
-			return -1;
-	if (count == 0)
-		return -1;
+		if (coremask[i] != '0') {
+			RTE_LOG(ERR, EAL, "invalid characters in coremask: %s\n",
+					coremask_copy);
+			goto err;
+		}
+	if (count == 0) {
+		RTE_LOG(ERR, EAL, "No lcores in coremask: %s\n", coremask_copy);
+		goto err;
+	}
+
+	if (check_core_list(lcores, count))
+		goto err;
+
+	/*
+	 * Now that we've gto a list of cores no longer than
+	 * RTE_MAX_LCORE, and no lcore in that list is greater
+	 * than RTE_MAX_LCORE, populate the cores
+	 * array and return.
+	 */
+	for (k = 0; k < count; k++)
+		cores[lcores[k]] = k;
+
+	if (coremask_copy)
+		free(coremask_copy);
+
 	return 0;
+err:
+	if (coremask_copy)
+		free(coremask_copy);
+	return -1;
 }
 
 static int
-- 
2.17.1