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

use hashtabe instead of linear list to check kcontrol before
adding them for improving early audio KPI.

Change-Id: I7134816736e08e338c0f22a8ae283a0520aa847a
Signed-off-by: Raghu Bankapur <quic_rbankapu@quicinc.com>
---
 include/sound/control.h |  4 ++
 include/sound/core.h    | 12 +++++-
 sound/core/control.c    | 92 +++++++++++++++++++++++++++++++++--------
 sound/core/init.c       |  3 ++
 sound/soc/Kconfig       |  9 ++++
 5 files changed, 101 insertions(+), 19 deletions(-)

On Sun, May 29, 2022 at 02:20:09PM +0530, Raghu Bankapur wrote:

> index 5dcf77af07af..0eb18f8ee6fd 100644
> --- a/sound/soc/Kconfig
> +++ b/sound/soc/Kconfig
> @@ -58,6 +58,15 @@ config SND_SOC_TOPOLOGY_KUNIT_TEST
>  config SND_SOC_ACPI
>  	tristate
>  
> +config SND_CTL_HASHTABLE
> +	bool "Add SND CTL hashtable"
> +	help
> +	  This enables hash table in sound card for kcontrols. The traditional way is

Since the rest of the change is to the ALSA core this should be
in the core ALSA Kconfig, though I'm also wondering if there's
any reason to make it configurable at all - is there any big
downside to just using the hastable all the time?  This sort of
tuning control tends to be a bit unclear for users.

Hi Raghu,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tiwai-sound/for-next]
[also build test WARNING on broonie-sound/for-next v5.18 next-20220527]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Raghu-Bankapur/asoc-msm-use-hashtable-to-check-kcontrol/20220529-165246
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git for-next
config: arm64-randconfig-r036-20220531 (https://download.01.org/0day-ci/archive/20220531/202205311233.abvVh5rg-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project c825abd6b0198fb088d9752f556a70705bc99dfd)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/244d3a3d274761ea83000880d73cc9b0a01b2a4a
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Raghu-Bankapur/asoc-msm-use-hashtable-to-check-kcontrol/20220529-165246
        git checkout 244d3a3d274761ea83000880d73cc9b0a01b2a4a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/clk/mediatek/ sound/core/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> sound/core/control.c:375:14: warning: no previous prototype for function 'snd_ctl_strtoint' [-Wmissing-prototypes]
   unsigned int snd_ctl_strtoint(const char *s)
                ^
   sound/core/control.c:375:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   unsigned int snd_ctl_strtoint(const char *s)
   ^
   static 
   1 warning generated.


vim +/snd_ctl_strtoint +375 sound/core/control.c

   373	
   374	/* Used to convert the string into int value -- BKDRHash */
 > 375	unsigned int snd_ctl_strtoint(const char *s)
   376	{
   377		unsigned int res = 0;
   378	
   379		while (*s)
   380			res = (res << 5) - res + (*s++);
   381	
   382		return (res & 0x7FFFFFFF);
   383	}
   384

Hi Takashi

Our implementation also falls inline with your approach [PATCH RFC] 
ALSA: control: Use xarray for faster lookups (kernel.org) 
<https://lore.kernel.org/all/20211028130027.18764-1-tiwai@suse.de/T/>, 
but you approach looks to be clean with xarray.

is it possible to upstream those changes?

Regards

Raghu Bankapur

On 5/29/2022 3:05 PM, Takashi Iwai wrote:
> On Sun, 29 May 2022 10:50:09 +0200,
> Raghu Bankapur wrote:
>> use hashtabe instead of linear list to check kcontrol before
>> adding them for improving early audio KPI.
>>
>> Change-Id: I7134816736e08e338c0f22a8ae283a0520aa847a
>> Signed-off-by: Raghu Bankapur<quic_rbankapu@quicinc.com>
> Aha, interesting, a faster lookup is indeed measurable and needed.
>
> One point with your patch is whether it works when a control element
> gets removed dynamically.  It's often the case with the user-space
> kctls.  Also, multiple ctl elements may have the same name string but
> with different index or device number.  Comparing only the string
> isn't enough.  (And I wonder how about the hash key collision.)
>
> FWIW, I posted an RFC patch faster lookup with Xarray some time ago:
>    https://lore.kernel.org/all/20211028130027.18764-1-tiwai@suse.de/T/
>
>
> thanks,
>
> Takashi
>
>
>> ---
>>   include/sound/control.h |  4 ++
>>   include/sound/core.h    | 12 +++++-
>>   sound/core/control.c    | 92 +++++++++++++++++++++++++++++++++--------
>>   sound/core/init.c       |  3 ++
>>   sound/soc/Kconfig       |  9 ++++
>>   5 files changed, 101 insertions(+), 19 deletions(-)
>>
>> diff --git a/include/sound/control.h b/include/sound/control.h
>> index 985c51a8fb74..1b85d36c2066 100644
>> --- a/include/sound/control.h
>> +++ b/include/sound/control.h
>> @@ -70,6 +70,10 @@ struct snd_kcontrol_volatile {
>>   struct snd_kcontrol {
>>   	struct list_head list;		/* list of controls */
>>   	struct snd_ctl_elem_id id;
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +	struct hlist_node hnode;
>> +	unsigned int knametoint;		/* kctl name to uint, hash key value */
>> +#endif
>>   	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..dd6714fc43ff 100644
>> --- a/include/sound/core.h
>> +++ b/include/sound/core.h
>> @@ -14,7 +14,9 @@
>>   #include <linux/pm.h>			/* pm_message_t */
>>   #include <linux/stringify.h>
>>   #include <linux/printk.h>
>> -
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +#include <linux/hashtable.h>
>> +#endif
>>   /* number of supported soundcards */
>>   #ifdef CONFIG_SND_DYNAMIC_MINORS
>>   #define SNDRV_CARDS CONFIG_SND_MAX_CARDS
>> @@ -24,6 +26,10 @@
>>   
>>   #define CONFIG_SND_MAJOR	116	/* standard configuration */
>>   
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +#define SND_CTL_HASH_TABLE_BITS 14	/* buckets numbers: 1 << 14 */
>> +#endif
>> +
>>   /* forward declarations */
>>   struct pci_dev;
>>   struct module;
>> @@ -103,7 +109,9 @@ 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 */
>> -
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +	DECLARE_HASHTABLE(ctl_htable, SND_CTL_HASH_TABLE_BITS);
>> +#endif
>>   	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..914d05647497 100644
>> --- a/sound/core/control.c
>> +++ b/sound/core/control.c
>> @@ -368,6 +368,47 @@ enum snd_ctl_add_mode {
>>   	CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
>>   };
>>   
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +char snd_ctl_string[50] = { '\0' };
>> +
>> +/* Used to convert the string into int value -- BKDRHash */
>> +unsigned int snd_ctl_strtoint(const char *s)
>> +{
>> +	unsigned int res = 0;
>> +
>> +	while (*s)
>> +		res = (res << 5) - res + (*s++);
>> +
>> +	return (res & 0x7FFFFFFF);
>> +}
>> +
>> +/**
>> + * 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)
>> +{
>> +	struct snd_kcontrol *kctl = NULL;
>> +
>> +	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 NULL;
>> +}
>> +#endif
>> +
>>   /* 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,
>> @@ -382,24 +423,38 @@ 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;
>> -		}
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +	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;
>> +
>> +	old = snd_ctl_hash_check(card, kcontrol->knametoint);
>> +	if (old) {
>> +#endif
>> +		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;
>> +		}
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +	}
>> +#endif
>>   	if (snd_ctl_find_hole(card, kcontrol->count) < 0)
>>   		return -ENOMEM;
>>   
>> @@ -410,7 +465,10 @@ 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);
>> -
>> +		
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +	hash_add(card->ctl_htable, &kcontrol->hnode, kcontrol->knametoint);
>> +#endif
>>   	return 0;
>>   }
>>   
>> diff --git a/sound/core/init.c b/sound/core/init.c
>> index 31ba7024e3ad..fda38b2137ee 100644
>> --- a/sound/core/init.c
>> +++ b/sound/core/init.c
>> @@ -284,6 +284,9 @@ 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);
>> +#ifdef CONFIG_SND_CTL_HASHTABLE
>> +	hash_init(card->ctl_htable);
>> +#endif
>>   	mutex_init(&card->memory_mutex);
>>   #ifdef CONFIG_PM
>>   	init_waitqueue_head(&card->power_sleep);
>> diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
>> index 5dcf77af07af..0eb18f8ee6fd 100644
>> --- a/sound/soc/Kconfig
>> +++ b/sound/soc/Kconfig
>> @@ -58,6 +58,15 @@ config SND_SOC_TOPOLOGY_KUNIT_TEST
>>   config SND_SOC_ACPI
>>   	tristate
>>   
>> +config SND_CTL_HASHTABLE
>> +	bool "Add SND CTL hashtable"
>> +	help
>> +	  This enables hash table in sound card for kcontrols. The traditional way is
>> +	  traversing the linked list of controls and compare each exsiting control with
>> +	  the new kcontrol to find out whether there are duplicate kcontrols, which will
>> +	  consumes much time during bootup. Enable this will use hash table instead of
>> +	  linked list to check new kcontrol and reduce much time for sound card registration.
>> +
>>   # All the supported SoCs
>>   source "sound/soc/adi/Kconfig"
>>   source "sound/soc/amd/Kconfig"
>> -- 
>> 2.17.1
>>