Speed up Asp.net gridview databind

Question

I have an ASP.net gridview with bootstrap 3 styles applied and its inside an Update panel. When I bind the grid It takes more than a minute to load but the actual SP takes just 3 sec to load data. Is there any way I could speedup the databind

C#

DataSet ds = GetSearchResults(grdattendee_search.PageIndex);
Session["attendee"] = ds.Tables[0];
grdattendee_search.DataSource = ds.Tables[0];
grdattendee_search.DataBind();


protected void grdattendee_search_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    grdattendee_search.PageIndex = e.NewPageIndex;
    if (Session["attendee"] != null)
    {
        grdattendee_search.DataSource = Session["attendee"];
        grdattendee_search.DataBind();
    }
    else
    bindgrid();
}

Aspx

<asp:GridView ID="grdattendee_search" runat="server" AllowPaging="true" PageSize="10"
                        AutoGenerateColumns="false" CssClass="table table-hover" DataKeyNames="ID"
                        GridLines="Horizontal" BorderStyle="None" PagerStyle-CssClass="bs-pagination"
                        OnRowCommand="grdattendee_search_RowCommand" OnPageIndexChanging="grdattendee_search_PageIndexChanging">
                        <Columns>
                            <asp:BoundField DataField="ID" HeaderText="ID" ReadOnly="True" SortExpression="ID"
                                Visible="false" />
                            <asp:TemplateField HeaderText="Name" SortExpression="Name">
                                <ItemTemplate>
                                    <%-- <asp:HyperLink ID="HyperLink1" runat="server" Text='<%# Eval("Name")%>'></asp:HyperLink>--%>
                                    <asp:LinkButton ID="btn" runat="server" CommandName="select" CommandArgument="<%# ((GridViewRow) Container).RowIndex %>"
                                        Text='<%# string.Concat(Eval("name_first"), " ", Eval("name_last"))%>'></asp:LinkButton>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:BoundField DataField="Degree" HeaderText="Degree" SortExpression="Degree" />
                            <asp:BoundField DataField="specialty" HeaderText="Specialty" SortExpression="specialty" />
                            <asp:BoundField DataField="city" HeaderText="City" SortExpression="city" />
                            <asp:BoundField DataField="state" HeaderText="State" SortExpression="state" />
                        </Columns>
                    </asp:GridView>

Answer 1

Identified the issue. The issue is not with the binding. Another process in the page load is blocking the current data binding.