Is working with weights feasible?

I'm setting up a layout here and after including the property: android: layout_weight , eclipse returns a warning: 'nested weights bad for performance'.

Why working with this property is bad for performance? And to what extent, will this influence performance?

Thank you.

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:layout_weight="1">


        <TextView 
            android:id="@+id/tv_codProduto"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.3"     //Advertência aparece aqui
            android:text="Código Produto:" />

        <TextView 
            android:id="@+id/tv_descProduto"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.7"
            android:text="Descrição:" />
    </LinearLayout>

    <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:layout_weight="1">

        <EditText 
            android:id="@+id/et_codProduto"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.3"           //Advertência aparece aqui
            android:inputType="none"/>

        <EditText 
            android:id="@+id/et_descProduto"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="0.7"
            android:inputType="none"/>
    </LinearLayout>

    <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView 
            android:id="@+id/tv_complemento"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Complemento:"/>
        <EditText
            android:id="@+id/ed_complemento"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:inputType="none"/>
    </LinearLayout>

    <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:layout_weight="1">

        <TextView 
            android:id="@+id/tv_qtdeEstoque"
            android:layout_weight="0.5"          //Advertência aparece aqui
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="Estoque:"
            android:inputType="none"/>
        <TextView 
            android:id="@+id/tv_vrVenda"
            android:layout_weight="0.5"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="Valor de Venda:"/>
    </LinearLayout>

    <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:layout_weight="1">

<EditText
            android:id="@+id/ed_qtdeEstoque"
            android:layout_width="0dp"
            android:layout_weight="0.5"          //Advertência aparece aqui
            android:layout_height="wrap_content"
            android:inputType="none"/>

        <EditText
            android:id="@+id/ed_vrVenda"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:ems="10" />

    </LinearLayout>

    <LinearLayout 
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView 
            android:id="@+id/tv_fornecedor"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="Fornecedor:"/>
        <EditText 
            android:id="@+id/ed_fornecedor"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:inputType="none"/>
    </LinearLayout>
    </LinearLayout>