[v4,1/2] eal: add additional info if core list too long

Message ID 20210922122920.34759-1-david.hunt@intel.com (mailing list archive)
State Superseded, archived
Delegated to: David Marchand
Headers
Series [v4,1/2] eal: add additional info if core list too long |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Hunt, David Sept. 22, 2021, 12:29 p.m. UTC
  If the user requests to use an lcore above 128 using -l,
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.

For example, if "-l 12-16,130,132" is used, we see the following
additional output on the command line:

EAL: lcore 132 >= RTE_MAX_LCORE (128)
EAL: lcore 133 >= RTE_MAX_LCORE (128)
EAL: to use high physical core ids , please use --lcores to map
them to lcore ids below RTE_MAX_LCORE,
EAL:     e.g. --lcores 0@12,1@13,2@14,3@15,4@16,5@132,6@133

Signed-off-by: David Hunt <david.hunt@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
changes in v2
   * Rather than increasing the default max lcores (as in v1),
     it was agreed to do this instead (switch to --lcores).
   * As the other patches in the v1 of the set are no longer related
     to this change, I'll submit as a separate patch set.
changes in v3
   * separated out some of the corelist cheking into separate function
   * added extra messages for the different failure conditions.
   * changed allocation of the core strings from static to dynamic
   * now prints out a message for each core above RTE_MAX_LCORE
changes in v4
   * tweaked log messages to be a bit clearer about mapping lcores
     to physical cores.
   * improved indenting of log messages.
   * fixed bug in overrunning end of lcore array
   * switched from strlcpy to strdup because of a clang error
---
---
 lib/eal/common/eal_common_options.c | 100 ++++++++++++++++++++++++----
 1 file changed, 87 insertions(+), 13 deletions(-)
  

Comments

David Marchand Sept. 23, 2021, 8:11 a.m. UTC | #1
On Wed, Sep 22, 2021 at 2:29 PM David Hunt <david.hunt@intel.com> wrote:
>
> If the user requests to use an lcore above 128 using -l,
> 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.
>
> For example, if "-l 12-16,130,132" is used, we see the following
> additional output on the command line:
>
> EAL: lcore 132 >= RTE_MAX_LCORE (128)
> EAL: lcore 133 >= RTE_MAX_LCORE (128)
> EAL: to use high physical core ids , please use --lcores to map
> them to lcore ids below RTE_MAX_LCORE,
> EAL:     e.g. --lcores 0@12,1@13,2@14,3@15,4@16,5@132,6@133
>
> Signed-off-by: David Hunt <david.hunt@intel.com>
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>

This series is there to help users, it should not break existing
working configurations.

I mentionned the "-l 0-3,0" case before.
This syntax is debatable, but it worked before (see comment below) and
this patch now refuses it.


> ---
> changes in v2
>    * Rather than increasing the default max lcores (as in v1),
>      it was agreed to do this instead (switch to --lcores).
>    * As the other patches in the v1 of the set are no longer related
>      to this change, I'll submit as a separate patch set.
> changes in v3
>    * separated out some of the corelist cheking into separate function
>    * added extra messages for the different failure conditions.
>    * changed allocation of the core strings from static to dynamic
>    * now prints out a message for each core above RTE_MAX_LCORE
> changes in v4
>    * tweaked log messages to be a bit clearer about mapping lcores
>      to physical cores.
>    * improved indenting of log messages.
>    * fixed bug in overrunning end of lcore array
>    * switched from strlcpy to strdup because of a clang error
> ---
> ---
>  lib/eal/common/eal_common_options.c | 100 ++++++++++++++++++++++++----
>  1 file changed, 87 insertions(+), 13 deletions(-)
>
> diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
> index eaef57312f..de1717946f 100644
> --- a/lib/eal/common/eal_common_options.c
> +++ b/lib/eal/common/eal_common_options.c
> @@ -703,6 +703,47 @@ update_lcore_config(int *cores)
>         return ret;
>  }
>
> +static int
> +check_core_list(int *lcores, unsigned int count)
> +{
> +       unsigned int i, j;

One index variable is enough.


> +       char *lcorestr;
> +       int len = 0;
> +       bool overflow = false;
> +
> +       for (j = 0; j < count; j++) {
> +               if (lcores[j] >= RTE_MAX_LCORE) {
> +                       RTE_LOG(ERR, EAL, "lcore %d >= RTE_MAX_LCORE (%d)\n",
> +                                       lcores[j], RTE_MAX_LCORE);
> +                       overflow = true;
> +               }
> +       }

if (!overflow)
    return 0;

> +       if (overflow) {
> +               /*
> +                * If we've encountered a core that's greater than
> +                * RTE_MAX_LCORE, suggest using --lcores option to
> +                * map lcores onto physical cores greater than
> +                * RTE_MAX_LCORE, then return.
> +                */
> +               lcorestr = calloc(1, RTE_MAX_LCORE * 10);

Ugly but works as long as RTE_MAX_LCORE < 10k.
I hope static analysis tools won't complain with the snprintf below
where there is no check on return value.


> +               if (lcorestr == NULL) {
> +                       RTE_LOG(ERR, EAL, "Unable to allocate lcore string\n");
> +                       return -ENOMEM;
> +               }
> +               for (i = 0; i < count; i++)
> +                       len = len + snprintf(&lcorestr[len],
> +                                       RTE_MAX_LCORE * 10 - len,
> +                                       "%d@%d,", i, lcores[i]);
> +               if (len > 0)
> +                       lcorestr[len-1] = 0;

len - 1


> +               RTE_LOG(ERR, EAL, "to use high physical core ids , please use --lcores to map them to lcore ids below RTE_MAX_LCORE,\n");
> +               RTE_LOG(ERR, EAL, "    e.g. --lcores %s\n", lcorestr);
> +               free(lcorestr);
> +               return -1;
> +       }
> +       return 0;
> +}
> +
>  static int
>  eal_parse_coremask(const char *coremask, int *cores)
>  {
> @@ -833,54 +874,87 @@ eal_parse_service_corelist(const char *corelist)
>  static int
>  eal_parse_corelist(const char *corelist, int *cores)
>  {
> -       unsigned count = 0;
> +       unsigned int count = 0, k;

No need for k, count is enough.


>         char *end = NULL;
>         int min, max;
>         int idx;
> +       int lcores[RTE_MAX_LCORE];
> +       char *corelist_copy;

corelist_copy is unused.


>
>         for (idx = 0; idx < RTE_MAX_LCORE; idx++)
>                 cores[idx] = -1;
>
> +       corelist_copy = strdup(corelist);
> +       if (corelist_copy == NULL) {
> +               RTE_LOG(ERR, EAL, "Unable to duplicate corelist\n");
> +               return -ENOMEM;
> +       }
> +
>         /* Remove all blank characters ahead */
>         while (isblank(*corelist))
>                 corelist++;
>
>         /* Get list of cores */
> -       min = RTE_MAX_LCORE;
> +       min = -1;
>         do {
>                 while (isblank(*corelist))
>                         corelist++;
>                 if (*corelist == '\0')
> -                       return -1;
> +                       goto err;
>                 errno = 0;
>                 idx = strtol(corelist, &end, 10);
>                 if (errno || end == NULL)
> -                       return -1;
> -               if (idx < 0 || idx >= RTE_MAX_LCORE)
> -                       return -1;
> +                       goto err;
> +               if (idx < 0)
> +                       goto err;
>                 while (isblank(*end))
>                         end++;
>                 if (*end == '-') {
>                         min = idx;
>                 } else if ((*end == ',') || (*end == '\0')) {
>                         max = idx;
> -                       if (min == RTE_MAX_LCORE)
> +                       if (min == -1)
>                                 min = idx;
>                         for (idx = min; idx <= max; idx++) {
> -                               if (cores[idx] == -1) {
> -                                       cores[idx] = count;
> -                                       count++;

Here, in the original code, "duplicates" were accepted/ignored.


> +                               if (count < RTE_MAX_LCORE)
> +                                       lcores[count++] = idx;
> +                               else {
> +                                       RTE_LOG(ERR, EAL, "Too many lcores provided. Cannot exceed %d\n",
> +                                                       RTE_MAX_LCORE);
> +                                       goto err;
>                                 }
>                         }
> -                       min = RTE_MAX_LCORE;
> +                       min = -1;
>                 } else
> -                       return -1;
> +                       goto err;
>                 corelist = end + 1;
>         } while (*end != '\0');
>
>         if (count == 0)
> -               return -1;
> +               goto err;
> +
> +       if (check_core_list(lcores, count))
> +               goto err;
> +
> +       /*
> +        * Now that we've gto a list of cores no longer than

typo.

> +        * 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;

do {
   count--;
   cores[lcores[count]] = count;
while (count != 0);


    cores[count]

> +
> +       if (corelist_copy)
> +               free(corelist_copy);
> +
>         return 0;
> +err:
> +       if (corelist_copy)
> +               free(corelist_copy);
> +
> +       return -1;
>  }
>
>  /* Changes the lcore id of the main thread */
> --
> 2.17.1
>
  
Hunt, David Sept. 23, 2021, 9:47 a.m. UTC | #2
On 23/9/2021 9:11 AM, David Marchand wrote:
> On Wed, Sep 22, 2021 at 2:29 PM David Hunt <david.hunt@intel.com> wrote:
>> If the user requests to use an lcore above 128 using -l,
>> 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.
>>
>> For example, if "-l 12-16,130,132" is used, we see the following
>> additional output on the command line:
>>
>> EAL: lcore 132 >= RTE_MAX_LCORE (128)
>> EAL: lcore 133 >= RTE_MAX_LCORE (128)
>> EAL: to use high physical core ids , please use --lcores to map
>> them to lcore ids below RTE_MAX_LCORE,
>> EAL:     e.g. --lcores 0@12,1@13,2@14,3@15,4@16,5@132,6@133
>>
>> Signed-off-by: David Hunt <david.hunt@intel.com>
>> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
> This series is there to help users, it should not break existing
> working configurations.
>
> I mentionned the "-l 0-3,0" case before.
> This syntax is debatable, but it worked before (see comment below) and
> this patch now refuses it.
>

Hi David,

Good point that the patch should not change behaviour. Will address, 
along with your other comments.

Thanks,
Dave.



--snip--
  

Patch

diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
index eaef57312f..de1717946f 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -703,6 +703,47 @@  update_lcore_config(int *cores)
 	return ret;
 }
 
+static int
+check_core_list(int *lcores, unsigned int count)
+{
+	unsigned int i, j;
+	char *lcorestr;
+	int len = 0;
+	bool overflow = false;
+
+	for (j = 0; j < count; j++) {
+		if (lcores[j] >= RTE_MAX_LCORE) {
+			RTE_LOG(ERR, EAL, "lcore %d >= RTE_MAX_LCORE (%d)\n",
+					lcores[j], RTE_MAX_LCORE);
+			overflow = true;
+		}
+	}
+	if (overflow) {
+		/*
+		 * If we've encountered a core that's greater than
+		 * RTE_MAX_LCORE, suggest using --lcores option to
+		 * map lcores onto physical cores greater than
+		 * RTE_MAX_LCORE, then return.
+		 */
+		lcorestr = calloc(1, RTE_MAX_LCORE * 10);
+		if (lcorestr == NULL) {
+			RTE_LOG(ERR, EAL, "Unable to allocate lcore string\n");
+			return -ENOMEM;
+		}
+		for (i = 0; i < count; i++)
+			len = len + snprintf(&lcorestr[len],
+					RTE_MAX_LCORE * 10 - len,
+					"%d@%d,", i, lcores[i]);
+		if (len > 0)
+			lcorestr[len-1] = 0;
+		RTE_LOG(ERR, EAL, "to use high physical core ids , please use --lcores to map them to lcore ids below RTE_MAX_LCORE,\n");
+		RTE_LOG(ERR, EAL, "    e.g. --lcores %s\n", lcorestr);
+		free(lcorestr);
+		return -1;
+	}
+	return 0;
+}
+
 static int
 eal_parse_coremask(const char *coremask, int *cores)
 {
@@ -833,54 +874,87 @@  eal_parse_service_corelist(const char *corelist)
 static int
 eal_parse_corelist(const char *corelist, int *cores)
 {
-	unsigned count = 0;
+	unsigned int count = 0, k;
 	char *end = NULL;
 	int min, max;
 	int idx;
+	int lcores[RTE_MAX_LCORE];
+	char *corelist_copy;
 
 	for (idx = 0; idx < RTE_MAX_LCORE; idx++)
 		cores[idx] = -1;
 
+	corelist_copy = strdup(corelist);
+	if (corelist_copy == NULL) {
+		RTE_LOG(ERR, EAL, "Unable to duplicate corelist\n");
+		return -ENOMEM;
+	}
+
 	/* Remove all blank characters ahead */
 	while (isblank(*corelist))
 		corelist++;
 
 	/* Get list of cores */
-	min = RTE_MAX_LCORE;
+	min = -1;
 	do {
 		while (isblank(*corelist))
 			corelist++;
 		if (*corelist == '\0')
-			return -1;
+			goto err;
 		errno = 0;
 		idx = strtol(corelist, &end, 10);
 		if (errno || end == NULL)
-			return -1;
-		if (idx < 0 || idx >= RTE_MAX_LCORE)
-			return -1;
+			goto err;
+		if (idx < 0)
+			goto err;
 		while (isblank(*end))
 			end++;
 		if (*end == '-') {
 			min = idx;
 		} else if ((*end == ',') || (*end == '\0')) {
 			max = idx;
-			if (min == RTE_MAX_LCORE)
+			if (min == -1)
 				min = idx;
 			for (idx = min; idx <= max; idx++) {
-				if (cores[idx] == -1) {
-					cores[idx] = count;
-					count++;
+				if (count < RTE_MAX_LCORE)
+					lcores[count++] = idx;
+				else {
+					RTE_LOG(ERR, EAL, "Too many lcores provided. Cannot exceed %d\n",
+							RTE_MAX_LCORE);
+					goto err;
 				}
 			}
-			min = RTE_MAX_LCORE;
+			min = -1;
 		} else
-			return -1;
+			goto err;
 		corelist = end + 1;
 	} while (*end != '\0');
 
 	if (count == 0)
-		return -1;
+		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 (corelist_copy)
+		free(corelist_copy);
+
 	return 0;
+err:
+	if (corelist_copy)
+		free(corelist_copy);
+
+	return -1;
 }
 
 /* Changes the lcore id of the main thread */