• Denys Vlasenko's avatar
    net: deinline netif_tx_stop_all_queues(), remove WARN_ON in netif_tx_stop_queue() · a2029240
    Denys Vlasenko authored
    These functions compile to 60 bytes of machine code each.
    With this .config: http://busybox.net/~vda/kernel_config
    there are 617 calls of netif_tx_stop_queue()
    and 49 calls of netif_tx_stop_all_queues() in vmlinux.
    
    To fix this, remove WARN_ON in netif_tx_stop_queue()
    as suggested by davem, and deinline netif_tx_stop_all_queues().
    
    Change in code size is about 20k:
    
       text      data      bss       dec     hex filename
    82426986 22255416 20627456 125309858 77813a2 vmlinux.before
    82406248 22255416 20627456 125289120 777c2a0 vmlinux
    
    gcc-4.7.2 still creates deinlined version of netif_tx_stop_queue
    sometimes:
    
    $ nm --size-sort vmlinux | grep netif_tx_stop_queue | wc -l
    190
    
    ffffffff81b558a8 <netif_tx_stop_queue>:
    ffffffff81b558a8:       55                      push   %rbp
    ffffffff81b558a9:       48 89 e5                mov    %rsp,%rbp
    ffffffff81b558ac:       f0 80 8f e0 01 00 00    lock orb $0x1,0x1e0(%rdi)
    ffffffff81b558b3:       01
    ffffffff81b558b4:       5d                      pop    %rbp
    ffffffff81b558b5:       c3                      retq
    
    This needs additional fixing.
    Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
    CC: Alexei Starovoitov <alexei.starovoitov@gmail.com>
    CC: Alexander Duyck <alexander.duyck@gmail.com>
    CC: Joe Perches <joe@perches.com>
    CC: David S. Miller <davem@davemloft.net>
    CC: Jiri Pirko <jpirko@redhat.com>
    CC: linux-kernel@vger.kernel.org
    CC: netdev@vger.kernel.org
    CC: netfilter-devel@vger.kernel.org
    Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    a2029240
dev.c 186 KB