On Mon, Sep 15, 2014 at 2:03 PM, Alex Wang <al...@nicira.com> wrote:
> This commit adds support in ovs-numa module for reading a user
> specified cpu mask, which configures the availability of the cores.
>
> The cpu mask has the format of a hex string similar to the EAL '-c
> COREMASK' option input or the 'taskset' mask input. The lowest order
> bit corresponds to the first CPU core. Bit value '1' means the
> corresponding core is available.
>
> An upcoming patch will allow user to configure the mask via OVSDB.
>
> Signed-off-by: Alex Wang <al...@nicira.com>
> ---
> lib/ovs-numa.c | 93
> +++++++++++++++++++++++++++++++++++++++++++++++---------
> lib/ovs-numa.h | 7 +++++
> 2 files changed, 86 insertions(+), 14 deletions(-)
>
> diff --git a/lib/ovs-numa.c b/lib/ovs-numa.c
> index 7da1407..c4a9727 100644
> --- a/lib/ovs-numa.c
> +++ b/lib/ovs-numa.c
> @@ -69,6 +69,7 @@ struct cpu_core {
> struct list list_node; /* In 'numa_node->cores' list. */
> struct numa_node *numa; /* numa node containing the core. */
> int core_id; /* Core id. */
> + bool available; /* If the core can be pinned. */
> bool pinned; /* If a thread has been pinned to the core. */
> };
>
> @@ -123,6 +124,7 @@ discover_numa_and_core(void)
> list_insert(&n->cores, &c->list_node);
> c->core_id = core_id;
> c->numa = n;
> + c->available = true;
> n_cpus++;
> }
> }
> @@ -222,8 +224,8 @@ ovs_numa_get_n_cores_on_numa(int numa_id)
> return OVS_CORE_UNSPEC;
> }
>
> -/* Returns the number of unpinned cpu cores on numa node. Returns
> - * OVS_CORE_UNSPEC if 'numa_id' is invalid. */
> +/* Returns the number of cpu cores that are available and unpinned
> + * on numa node. Returns OVS_CORE_UNSPEC if 'numa_id' is invalid. */
> int
> ovs_numa_get_n_unpinned_cores_on_numa(int numa_id)
> {
> @@ -236,7 +238,7 @@ ovs_numa_get_n_unpinned_cores_on_numa(int numa_id)
> hash_int(numa_id, 0)),
> struct numa_node, hmap_node);
> LIST_FOR_EACH(core, list_node, &numa->cores) {
> - if (!core->pinned) {
> + if (core->available && !core->pinned) {
> count++;
> }
> }
> @@ -248,7 +250,8 @@ ovs_numa_get_n_unpinned_cores_on_numa(int numa_id)
> }
>
> /* Given 'core_id', tries to pin that core. Returns true, if succeeds.
> - * False, if the core has already been pinned or if 'core_id' is invalid. */
> + * False, if the core has already been pinned, or if it is invalid or
> + * not available. */
> bool
> ovs_numa_try_pin_core_specific(int core_id)
> {
> @@ -258,7 +261,7 @@ ovs_numa_try_pin_core_specific(int core_id)
> core = CONTAINER_OF(hmap_first_with_hash(&all_cpu_cores,
> hash_int(core_id, 0)),
> struct cpu_core, hmap_node);
> - if (!core->pinned) {
> + if (core->available && !core->pinned) {
> core->pinned = true;
> return true;
> }
> @@ -267,16 +270,16 @@ ovs_numa_try_pin_core_specific(int core_id)
> return false;
> }
>
> -/* Searches through all cores for an unpinned core. Returns the core_id
> - * if found and set the 'core->pinned' to true. Otherwise, returns
> - * OVS_CORE_UNSPEC. */
> +/* Searches through all cores for an unpinned and available core. Returns
> + * the 'core_id' if found and sets the 'core->pinned' to true. Otherwise,
> + * returns OVS_CORE_UNSPEC. */
> int
> ovs_numa_get_unpinned_core_any(void)
> {
> struct cpu_core *core;
>
> HMAP_FOR_EACH(core, hmap_node, &all_cpu_cores) {
> - if (!core->pinned) {
> + if (core->available && !core->pinned) {
> core->pinned = true;
> return core->core_id;
> }
> @@ -285,9 +288,9 @@ ovs_numa_get_unpinned_core_any(void)
> return OVS_CORE_UNSPEC;
> }
>
> -/* Searches through all cores on numa node with 'numa_id' for an unpinned
> - * core. Returns the core_id if found and sets the 'core->pinned' to true.
> - * Otherwise, returns OVS_CORE_UNSPEC. */
> +/* Searches through all cores on numa node with 'numa_id' for an
> + * unpinned and available core. Returns the core_id if found and
> + * sets the 'core->pinned' to true. Otherwise, returns OVS_CORE_UNSPEC. */
> int
> ovs_numa_get_unpinned_core_on_numa(int numa_id)
> {
> @@ -299,7 +302,7 @@ ovs_numa_get_unpinned_core_on_numa(int numa_id)
> hash_int(numa_id, 0)),
> struct numa_node, hmap_node);
> LIST_FOR_EACH(core, list_node, &numa->cores) {
> - if (!core->pinned) {
> + if (core->available && !core->pinned) {
> core->pinned = true;
> return core->core_id;
> }
> @@ -309,7 +312,7 @@ ovs_numa_get_unpinned_core_on_numa(int numa_id)
> return OVS_CORE_UNSPEC;
> }
>
> -/* Resets the 'core->pinned' for the core with 'core_id'. */
> +/* Unpins the core with 'core_id'. */
> void
> ovs_numa_unpin_core(int core_id)
> {
> @@ -323,4 +326,66 @@ ovs_numa_unpin_core(int core_id)
> }
> }
>
> +/* Reads the cpu mask configuration from 'cmask' and sets the
> + * 'available' of corresponding cores. For unspecified cores,
> + * sets 'available' to true. */
> +void
> +ovs_numa_set_cpu_mask(const char *cmask)
> +{
> + int core_id = 0;
> + int i;
> +
> + if (!found_numa_and_core) {
> + return;
> + }
> +
> + /* If no mask specified, resets the 'available' to true for all cores. */
> + if (!cmask) {
> + struct cpu_core *core;
> +
> + HMAP_FOR_EACH(core, hmap_node, &all_cpu_cores) {
> + core->available = true;
> + }
> +
> + return;
> + }
> +
> + for (i = strlen(cmask) - 1; i >= 0; i--) {
> + char hex = toupper(cmask[i]);
> + int bin, j;
> +
> + if (hex >= '0' && hex <= '9') {
> + bin = hex - '0';
> + } else if (hex >= 'A' && hex <= 'F') {
> + bin = hex - 'A' + 10;
> + } else {
> + bin = 0;
> + VLOG_WARN("Invalid cpu mask: %c", cmask[i]);
> + }
> +
> + for (j = 0; j < 4; j++) {
> + struct cpu_core *core;
> +
> + core = CONTAINER_OF(hmap_first_with_hash(&all_cpu_cores,
> + hash_int(core_id++, 0)),
> + struct cpu_core, hmap_node);
> + core->available = (bin >> j) & 0x1;
This can result in NULL pointer deref if cores are not multiple of 4.
I am not sure how "(bin >> j) & 0x1" works, easier way would be to
test for bits set in bin and then lookup the core.
> + }
> +
> + if (core_id >= hmap_count(&all_cpu_cores)) {
> + return;
> + }
> + }
> +
> + /* For unspecified cores, sets 'available' to false. */
> + while (core_id < hmap_count(&all_cpu_cores)) {
> + struct cpu_core *core;
> +
> + core = CONTAINER_OF(hmap_first_with_hash(&all_cpu_cores,
> + hash_int(core_id++, 0)),
> + struct cpu_core, hmap_node);
> + core->available = false;
> + }
> +}
> +
> #endif /* __linux__ */
> diff --git a/lib/ovs-numa.h b/lib/ovs-numa.h
> index 83732fc..fab2546 100644
> --- a/lib/ovs-numa.h
> +++ b/lib/ovs-numa.h
> @@ -31,6 +31,7 @@ void ovs_numa_init(void);
> bool ovs_numa_numa_id_is_valid(int numa_id);
> bool ovs_numa_core_id_is_valid(int core_id);
> int ovs_numa_get_n_numas(void);
> +void ovs_numa_set_cpu_mask(const char *cmask);
> int ovs_numa_get_n_cores(void);
> int ovs_numa_get_numa_id(int core_id);
> int ovs_numa_get_n_cores_on_numa(int numa_id);
> @@ -60,6 +61,12 @@ ovs_numa_core_id_is_valid(int core_id OVS_UNUSED)
> return false;
> }
>
> +static inline void
> +ovs_numa_set_cpu_mask(const char *cmask OVS_UNUSED)
> +{
> + /* Nothing */
> +}
> +
> static inline int
> ovs_numa_get_n_numas(void)
> {
> --
> 1.7.9.5
>
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