RE: Re: Re: [PATCH 1/1] stackdepot: interface to check entries and size of stackdepot.

[Vaneet Narang]

Hi Michal,

>>ÂWeÂhaveÂbeenÂgettingÂsimilarÂkindÂofÂsuchÂentriesÂandÂeventually
>>ÂstackdepotÂreachesÂMaxÂCap.ÂSoÂweÂfoundÂthisÂinterfaceÂusefulÂinÂdebugging
>>ÂstackdepotÂissueÂsoÂsharedÂinÂcommunity.
Â
>ThenÂuseÂitÂforÂinternalÂdebuggingÂandÂprovideÂaÂcodeÂwhichÂwouldÂscale
>betterÂonÂsmallerÂsystems.ÂWeÂdoÂnotÂneedÂthisÂinÂtheÂkernelÂIMHO.ÂWeÂdo
>notÂmergeÂallÂtheÂdebuggingÂpatchesÂweÂuseÂforÂinternalÂdevelopment.
`Â
Not just debugging but this information can also be used to profile and tune stack depot. 
Getting count of stack entries would help in deciding hash table size and 
page order used by stackdepot. 

For less entries, bigger hash table and higher page order slabs might not be required as 
maintained by stackdepot. As i already mentioned smaller size hashtable can be choosen and 
similarly lower order  pages can be used for slabs.

If you think its useful, we can share scalable patch to configure below two values based on 
number of stack entries dynamically.

#define STACK_ALLOC_ORDER 2 
#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER)


Regards,
Vaneet Narang