Re: [Qemu-devel] [PATCH v4] socket: Allocating Large sized arrays to heap

[Pooja Dhannawat]

On Friday, March 18, 2016, Paolo Bonzini <address@hidden> wrote:
>
>
> On 18/03/2016 14:49, Pooja Dhannawat wrote:
>>
>>
>>             If it is greater than the accepted level, the on-stack
>>             buffer is not
>>             used and you allocate one that has the right size on the heap.
>>
>>         Yes Okay. Thank you for the comments.
>>         I had one more question.
>>         size = qemu_recv(s->fd, buf1, sizeof(buf1), 0);
>>         The one above returns bytes read into buf1 (if large then bytes
>>         equivalent to len(buf1) is read) ?
>>         If true, size is the correct measure of buf1? Hence, I should
>>         compare the allowed stack size to "size" variable?
>>
>>        So isnt here size should be compared to "size" varibale paolo?
>>
>> So instead of comparing with NET_BUFSIZE, should I compare with "size"
>> variable? Can you help me with this?
>
> I was a bit confused myself; this function actually is a bit different
> from the others because it does not really need a large buffer.  The
> function already takes care of moving data in pieces from buf1 to
> s->buf.  If you make the buffer smaller, the only change is that one
> call to net_socket_send will process fewer bytes.
>
> So you can just send a trivial patch that changes the size of the array
> to something like 2048.
>
> Thanks, and sorry for putting you on a false track!
>
No, it's completely fine,  I really appreciate your help. 
> Paolo
>