How to debug throughput issues?

[Subhashini Rao Beerisetty]

On Wed, Jun 26, 2019 at 11:17 AM hariprasad kelam
<hariprasad.kelam at gmail.com> wrote:
>
> Hi subhashini,
>
> On Wed, 26 Jun, 2019, 10:56 AM Subhashini Rao Beerisetty, <subhashbeerisetty at gmail.com> wrote:
>>
>> On Wed, Jun 26, 2019 at 7:44 AM Hariprasad Kelam
>> <hariprasad.kelam at gmail.com> wrote:
>> >
>> > On Tue, Jun 25, 2019 at 10:26:54PM +0530, Subhashini Rao Beerisetty wrote:
>> > Hi  Subhashini,
>> >
>> > Please see inline,
>> > >  Hi All,
>> > >
>> > >  I’ve two Bluetooth dongles and connected to two Linux
>> > > systems(hostname1, hostname2). I’ve a test executable and it creates a
>> > > BT link does the file transfer and calculates the throughput.
>> > >
>> > Are these dongle supports classic mode or Ble?
>> It supports classic mode.
>>
>> > Which profile are you using to establish connection between these two? (
>> > PAN, ..etc)
>> > >  I repeated the same test with the same BT dongles on another
>> > > different Linux systems(hostname3, hostname4), here I’m getting less
>> > > data rate.
>> > >
>> > After inserting dongles to host are you getting serial interface
>> > /dev/tty* or hci interface ?
>> Using serial interface /dev/tty*
>> If it's inbuilt serial profile ..kernel simply creates serial interface.
>
>     You may focus on serial driver .
Does kernel has any tools to identify the costly(long time taken) API's?

>
>
>
>
>> > If its hci interface ,you can use hcidump to see packets  and check MTU
>> > size
>> > > Here first I want to narrow down whether the issue is below device
>> > > driver level or above device driver level and where the bottleneck is?
>> > > which tools will help me to debug this kind of issue?
>> > >
>> > I think before jumping into driver level ,its better to ensure all
>> > bluetooth parameters are same on both the setups.
>> Except the kernel version(hostname1 & 2 are having same kernel and it
>> differs with hostname3 & 4 kernel version) rest all other stuff is
>> same. So I'd like to know how to know which part of kernel mode
>> functions causing more delay and any tools are there to debug these
>> issues?
>>
>> >
>> > Thanks,
>> > Hariprasad k
>> > > Thanks
>> > >
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