Hello,
How to calculate instruction executed for function ?
For eg.
I need to calculate instruction executed for CMA_ALLOC function.
How many instruction executed for cma_alloc ?
Any help would be appreciated.
Regards,
Pankaj
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________________________________________
From: Pankaj Suryawanshi
Sent: 03 April 2019 19:50
To: [email protected]; [email protected]
Subject: How to calculate instruction executed for function
Hello,
How to calculate instruction executed for function ?
For eg.
I need to calculate instruction executed for CMA_ALLOC function.
How many instruction executed for cma_alloc ?
CMA_ALLOC :
for 1 cma_alloc success call there will around 75 instruction is executed, excluding jump, mutex,error case and debug info instruction.
below are mandatory jump calls that are required for successful allocations.
cma_bitmap_aligned_mask
cma_bitmap_aligned_offset
cma_bitmap_maxno
cma_bitmap_pages_to_bits
bitmap_find_next_zero_area_off -> find_next_zero_bit -> find_next_bit
bitmap_set
alloc_contig_range -> start_isolate_page_range
__alloc_contig_migrate_range -> isolate_migratepages_range -> reclaim_clean_pages_from_list -> shrink_page_list -> migrate_pages
So lets say
cma_bitmap_aligned_mask = 1 instrs
cma_bitmap_aligned_offset = 1 instrs
cma_bitmap_maxno = 1 instrs
cma_bitmap_pages_to_bits = 1 instrs
bitmap_find_next_zero_area_off -> find_next_zero_bit -> find_next_bit = 3 instrs
bitmap_set = 1 instrs
alloc_contig_range -> start_isolate_page_range =
has_unmovable_pages = 1 instrs
get_pfnblock_flags_mask = 1 instrs
set_pageblock_migratetype = 1 instrs
move_freepages_block = 1 instrn
__mod_zone_page_state = 1 instrs store info in vmstat
unset_migratetype_isolate = 1 instrs
__alloc_contig_migrate_range -> isolate_migratepages_range -> reclaim_clean_pages_from_list -> shrink_page_list -> migrate_pages
isolate_migratepages_range = 3 instrs
reclaim_clean_pages_from_list = 2 instrs
migrate_pages = 1 instrs
--------------------------------------------------------------
Total = around 20 instrs per page
20 ns per page on 1ghz processor is minimum excluding any overheads like mutex, variables, failure/error case,debug/prints.
I roughly calculated this.
Is it Correct ?
Any help would be appreciated.
Regards,
Pankaj
************************************************************************************************************************************************************* eInfochips Business Disclaimer: This e-mail message and all attachments transmitted with it are intended solely for the use of the addressee and may contain legally privileged and confidential information. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, copying, or other use of this message or its attachments is strictly prohibited. If you have received this message in error, please notify the sender immediately by replying to this message and please delete it from your computer. Any views expressed in this message are those of the individual sender unless otherwise stated. Company has taken enough precautions to prevent the spread of viruses. However the company accepts no liability for any damage caused by any virus transmitted by this email. *************************************************************************************************************************************************************