[PATCH V0 1/1] asoc: msm: use hashtable to check kcontrol

From: Raghu Bankapur
Date: Fri Jun 03 2022 - 06:42:36 EST


use hashtable instead of linear list to check kcontrol before
adding them for improving early audio KPI.
With this changes we see 600ms improvement in start of audio

Change-Id: I1a95d88ef41b48430b57307a0e6a8e82788b4372
Signed-off-by: Raghu Bankapur <quic_rbankapu@xxxxxxxxxxx>
---
include/sound/control.h | 2 +
include/sound/core.h | 5 +-
sound/core/control.c | 106 +++++++++++++++++++++++-----------------
sound/core/init.c | 1 +
4 files changed, 68 insertions(+), 46 deletions(-)

diff --git a/include/sound/control.h b/include/sound/control.h
index 985c51a8fb74..e50db5c45114 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -70,6 +70,8 @@ struct snd_kcontrol_volatile {
struct snd_kcontrol {
struct list_head list; /* list of controls */
struct snd_ctl_elem_id id;
+ struct hlist_node hnode;
+ unsigned int knametoint; /* kctl name to uint, hash key value */
unsigned int count; /* count of same elements */
snd_kcontrol_info_t *info;
snd_kcontrol_get_t *get;
diff --git a/include/sound/core.h b/include/sound/core.h
index b7e9b58d3c78..90341d6f1573 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -14,6 +14,7 @@
#include <linux/pm.h> /* pm_message_t */
#include <linux/stringify.h>
#include <linux/printk.h>
+#include <linux/hashtable.h>

/* number of supported soundcards */
#ifdef CONFIG_SND_DYNAMIC_MINORS
@@ -24,6 +25,8 @@

#define CONFIG_SND_MAJOR 116 /* standard configuration */

+#define SND_CTL_HASH_TABLE_BITS 14 /* buckets numbers: 1 << 14 */
+
/* forward declarations */
struct pci_dev;
struct module;
@@ -103,7 +106,7 @@ struct snd_card {
size_t user_ctl_alloc_size; // current memory allocation by user controls.
struct list_head controls; /* all controls for this card */
struct list_head ctl_files; /* active control files */
-
+ DECLARE_HASHTABLE(ctl_htable, SND_CTL_HASH_TABLE_BITS);
struct snd_info_entry *proc_root; /* root for soundcard specific files */
struct proc_dir_entry *proc_root_link; /* number link to real id */

diff --git a/sound/core/control.c b/sound/core/control.c
index a25c0d64d104..e00a02015837 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -331,43 +331,49 @@ void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
}
EXPORT_SYMBOL(snd_ctl_free_one);

-static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
- unsigned int count)
+enum snd_ctl_add_mode {
+ CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
+};
+
+char snd_ctl_string[50] = { '\0' };
+
+/* Used to convert the string into int value -- BKDRHash */
+static unsigned int snd_ctl_strtoint(const char *s)
{
- struct snd_kcontrol *kctl;
+ unsigned int res = 0;

- /* Make sure that the ids assigned to the control do not wrap around */
- if (card->last_numid >= UINT_MAX - count)
- card->last_numid = 0;
+ while (*s)
+ res = (res << 5) - res + (*s++);

- list_for_each_entry(kctl, &card->controls, list) {
- if (kctl->id.numid < card->last_numid + 1 + count &&
- kctl->id.numid + kctl->count > card->last_numid + 1) {
- card->last_numid = kctl->id.numid + kctl->count - 1;
- return true;
- }
- }
- return false;
+ return (res & 0x7FFFFFFF);
}

-static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
+/**
+ * snd_ctl_hash_check - Check the duplicate enrty on snd hashtable
+ * @card: the card instance
+ * @nametoint: kctl name to uint
+ *
+ * Finds the control instance with the given nametoint from the card.
+ *
+ * Return: The pointer of the instance if found, or %NULL if not.
+ *
+ */
+static struct snd_kcontrol *snd_ctl_hash_check(struct snd_card *card,
+ unsigned int nametoint)
{
- unsigned int iter = 100000;
+ struct snd_kcontrol *kctl = NULL;

- while (snd_ctl_remove_numid_conflict(card, count)) {
- if (--iter == 0) {
- /* this situation is very unlikely */
- dev_err(card->dev, "unable to allocate new control numid\n");
- return -ENOMEM;
- }
+ if (snd_BUG_ON(!card))
+ return NULL;
+
+ hash_for_each_possible(card->ctl_htable, kctl, hnode, nametoint) {
+ if (kctl->knametoint != nametoint)
+ continue;
+ return kctl;
}
- return 0;
+ return NULL;
}

-enum snd_ctl_add_mode {
- CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
-};
-
/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
static int __snd_ctl_add_replace(struct snd_card *card,
struct snd_kcontrol *kcontrol,
@@ -382,26 +388,34 @@ static int __snd_ctl_add_replace(struct snd_card *card,
if (id.index > UINT_MAX - kcontrol->count)
return -EINVAL;

- old = snd_ctl_find_id(card, &id);
- if (!old) {
- if (mode == CTL_REPLACE)
- return -EINVAL;
- } else {
- if (mode == CTL_ADD_EXCLUSIVE) {
- dev_err(card->dev,
- "control %i:%i:%i:%s:%i is already present\n",
- id.iface, id.device, id.subdevice, id.name,
- id.index);
- return -EBUSY;
- }
+ snprintf(snd_ctl_string, strlen(kcontrol->id.name) + 6, "%s%d%d%d",
+ kcontrol->id.name, kcontrol->id.iface, kcontrol->id.device,
+ kcontrol->id.subdevice);

- err = snd_ctl_remove(card, old);
- if (err < 0)
- return err;
- }
+ kcontrol->knametoint = snd_ctl_strtoint(snd_ctl_string);
+ if (kcontrol->knametoint < 0)
+ return -EINVAL;

- if (snd_ctl_find_hole(card, kcontrol->count) < 0)
- return -ENOMEM;
+ old = snd_ctl_hash_check(card, kcontrol->knametoint);
+ if (old) {
+ old = snd_ctl_find_id(card, &id);
+ if (!old) {
+ if (mode == CTL_REPLACE)
+ return -EINVAL;
+ } else {
+ if (mode == CTL_ADD_EXCLUSIVE) {
+ dev_err(card->dev,
+ "control %i:%i:%i:%s:%i is already present\n",
+ id.iface, id.device, id.subdevice, id.name,
+ id.index);
+ return -EBUSY;
+ }
+
+ err = snd_ctl_remove(card, old);
+ if (err < 0)
+ return err;
+ }
+ }

list_add_tail(&kcontrol->list, &card->controls);
card->controls_count += kcontrol->count;
@@ -411,6 +425,8 @@ static int __snd_ctl_add_replace(struct snd_card *card,
for (idx = 0; idx < kcontrol->count; idx++)
snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);

+ hash_add(card->ctl_htable, &kcontrol->hnode, kcontrol->knametoint);
+
return 0;
}

diff --git a/sound/core/init.c b/sound/core/init.c
index 31ba7024e3ad..24138902e5f2 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -284,6 +284,7 @@ static int snd_card_init(struct snd_card *card, struct device *parent,
INIT_LIST_HEAD(&card->ctl_files);
spin_lock_init(&card->files_lock);
INIT_LIST_HEAD(&card->files_list);
+ hash_init(card->ctl_htable);
mutex_init(&card->memory_mutex);
#ifdef CONFIG_PM
init_waitqueue_head(&card->power_sleep);
--
2.17.1