The translation lookaside buffer (TLB) enables modern CPUs to quickly map virtual memory addresses to physical memory addresses and vice versa. Operations that flush the TLB cause a performance hit until it is repopulated.
Questions tagged [tlb]
289 questions
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flush_cache_range() and flush_tlb_range() do not seem to work
Here is what I did:
A user space process uses malloc() to allocate memory on the heap and fills it with a specific pattern of characters and then spells out the address returned by the malloc().
The process id and the address of the memory chunk…
feeling_lonely
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3 answers
why does uboot invalidate TLB s, icache, BP array at beginning
On arm platform, the u-boot will invalidate TLBs, icache and BP array at beginning, but what's the reason? Is it necessary?
cpu_init_crit:
/*
* Invalidate L1 I/D
*/
mov r0, #0 @ set up for MCR
mcr p15, 0, r0, c8, c7, 0 @ invalidate…
user3194321
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Finding the appropriate stride for TLB misses in an array in a code snippet
Assume the system has a 32-entry TLB with a 8KB page size. What should MAX and stride be set to in order achieve a TLB miss upon pretty much every access to the array "data" ?
int value=0;
int data[MAX];
for (int j;j <1000; j++)
{
for (int i =0,…
Mona Jalal
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logical to physical address with tlb
i have to make a programm which "translates" logical addresses like 16916 to physical with tlb and page table! Are there any functions made for paging or i have to find some other way like arrays or lists?
user2735769
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rdtsc code that shows performance impacts from memory characterstics such as TLB miss
I was trying to understand rdtsc() and I came across the following code from http://www.mcs.anl.gov/~kazutomo/rdtsc.html.The text explaining the code reads "The next short benchmark code may show you some performance impacts from memory…
liv2hak
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1 answer
Translating from logical address to physical address. Logical addresses are hex
How do I go about converting hexadecimal addresses to physical addresses to answer this question? I am thoroughly confused and my teacher is no help due to language barrier.
Suppose a logical address space is 1KB, and the page-size is 16 bytes.…
user2559107
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Page faults, where are the secondary memory addresses stored
When there is a TLB miss, and the page is not resident in physical memory, the page is written back into physical memory and the page table and TLB are updated.
But where is address for the secondary memory stored? How does it know where to find the…
kbirk
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3 answers
What Virtual TLB?
Does anybody knows what does it mean by Virtual TLB, and what is the difference between this VTLB and the normal TLB .. I can't find a clear answer on Google?
Abdel Hegazi
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TLB physical addressing doesn't make sense to me
I'm reading, in a simple way, how do TLBs work and I don't understand something:
The TLB references physical memory addresses in its table. It may
reside between the CPU and the CPU cache, between the CPU cache and
primary storage memory, or…
Johnny Pauling
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4 answers
Relation between cache and TLB hit ratios
Following is the discription of the MMU of an operating system (Gate 2003 OS):
A processor uses 2-level page table for virtual to physical address
translation. Page table for both levels are stored in the main memory.
Virtual and physical…
Hegde
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1 answer
two-level paged memory exercise
Good morning everyone!
I'm struggling with an exercise of multilevel memory. Could someone help me in resolving it?
Consider a 2-level paged memory, with a size of 256MB, addressed to the byte and made up of 1024 pages, lets say :
(a) What are the…
nonso
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votes
2 answers
Cache Locality - weight of TLB, Cache Lines, and ...?
From my understanding the constructs which give rise to the high level concept of "cache locality" are the following:
Translation Lookaside Buffer (TLB) for virtual memory translation. Accessing the same virtual memory within the 4096 byte…
gmaggiol
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1 answer
How to import Component Object Model (COM) in Java?
I have a COM object with extension .tlb. How do I import it in Java and use it in my code?
Kutti
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1 answer
How To Make A Suitable .DLL for type-library conversion
I have incomplete types from my COM type library .tlb (which was generated by regasm OF .NET v4+) I am unsure if this is because cppc.exe derived the wrong header for it or if this is merely a symptom of it.
I know it's incomplete because all the…
Olivier10178
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2 answers
Linking between c# and c++ in 64 bit machine
I have written a code in c++ and c# . From my c++ code i am calling my c# function through. I have sent just a part of c++ code.
txtPath contains the location of a text file.
C++ code:
CoInitialize(NULL);
IMyClassPtr obj3;
…
shrey
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