Thank you for the response Tim.
sizeof(Person) is 48. Now, I know you said that it is not as
straightforward as looking just sizeof(Person). But when sizeof(Person) is
48 and I have
1728000 bytes allocated to Line 56, then is this more or less a certain
sign that something is wrong. Or, is 1728000 the total memory
that is ever used by the program in its entire run?
* 1728000 p = Person(id, ["H" => xHutil, "L" => 100 - xHutil],
goods["N"], 0.0, false, 0) # LINE 56*
Similarly, sizeof(Int) = 8. However, in line 66, I see the following.
* 51457 for i = 1:params.numPeople *
Given that numPeople=1000, should this be 8000 and not 51457?
Thank you.
On Friday, November 14, 2014 10:59:20 AM UTC-5, Tim Holy wrote:
>
> By "unexpected memory usage", it really means a line that shouldn't be
> allocating that nevertheless does. In your case, line 56 is explicitly
> allocating (it's creating a new Person object). You could check by using
> sizeof(Person) and seeing if the size is correct (but you'd have to
> include
> the size of the Dict, which because a Dict stores arrays is a bit
> recursive).
> Likewise, your push! command will grow the array, and hence allocate
> memory.
> That's being attributed to the first line of the for loop (the reasons are
> a
> little complex, and I'm late for a meeting).
>
> --Tim
>
> On Thursday, November 13, 2014 04:01:52 PM Test This wrote:
> > On performance tips page of the Julia documentation, it says that one
> way
> > to identify performance problems is to look for unexpected memory usage.
> >
> > As suggested, I ran the code with --track-allocation=user option.
> >
> > The following are some lines from my code (including the type
> definitions
> > at the beginning). For now, I have two questions:
> >
> > (1) How do I know what is appropriate/expected memory usage? That is,
> how
> > do I calculated expected appropriate usage? A related question is, is
> the
> > usage on line 56 appropriate.
> >
> > (2) What determines the memory usage for a for-loop? Is the usage on
> Line
> > 66 appropriate?
> >
> > Thank you.
> >
> >
> >
> > - ##
> > -------------------------------------------------------------------
> > - ## Custom types and constants
> > - ##
> > -------------------------------------------------------------------
> > -
> > - type Params
> > - minUtil::Int
> > - maxUtil::Int
> > - numPeople::Int
> > - w::Int # inversely related to the weight on reviews
> > - pReview::Float64
> > - numReps::Int
> > - recEveryX::Int
> > - end
> > -
> > -
> > - type Good
> > - name::ASCIIString
> > - mu::Int
> > - sigma::Int
> > - end
> > -
> > -
> > -
> > - type Person
> > - id::Int
> > - priors::Dict{ASCIIString, Float64}
> > - choice::Good
> > - util::Float64
> > - review::Bool #whether reviews or not
> > - stars::Int #if review=true then how many stars
> > - end
> > -
> > -
> > -
> > - ##
> >
> ===================================================================
> > - ## Functions
> > - ##
> >
> ===================================================================
> > -
> > - # Function to initialize a person
> > - function createPerson(params::Params,
> > - id::Int,
> > - xUtilDist::Dist.Uniform,
> > - goods::Dict{ASCIIString, Good})
> > - # draw xH value
> > 0 xHutil::Float64 = rand(xUtilDist)
> > * 1728000 p = Person(id, ["H" => xHutil, "L" => 100 - xHutil],
> > goods["N"], 0.0, false, 0) # LINE 56*
> > - end
> > -
> > -
> > - # create population of persons with there initial xH and xL
> > - function createPopulation(params::Params,
> > goods::Dict{ASCIIString, Good})
> > 288 popn::Array{Person, 1} = []
> > - #create a uniform distn with support [0, 100]
> > 0 unif = Dist.Uniform(params.minUtil, params.maxUtil)
> > -
> > * 51456 for i = 1:params.numPeople # LINE 66*
> > 0 p::Person = createPerson(params, i, unif, goods)
> > 0 push!(popn, p)
> > - end
> > -
> > 0 return popn
> > - end
>
>
