When I do something like this in a row:
<div class="col-sm-10" style="height: 100%; margin: 0px; padding: 0px;">
I added a comment, I will answer to give a detailed explanation.
col- has a padding in the bootstrap css, in order to remove that padding and have nested
col-s not show that extra padding you have to add the class
row to the parent div.
<div class="col-sm-2"> to
<div class="col-sm-2 row"> and remove
margin: 0px; padding: 0px; from nested div.
Hopefully I understood your question correctly.
Edited to fix some typos