• Amerigo Wang's avatar
    netpoll: revert 6bdb7fe3 and fix be_poll() instead · 072a9c48
    Amerigo Wang authored
    Against -net.
    
    In the patch "netpoll: re-enable irq in poll_napi()", I tried to
    fix the following warning:
    
    [100718.051041] ------------[ cut here ]------------
    [100718.051048] WARNING: at kernel/softirq.c:159 local_bh_enable_ip+0x7d/0xb0()
    (Not tainted)
    [100718.051049] Hardware name: ProLiant BL460c G7
    ...
    [100718.051068] Call Trace:
    [100718.051073]  [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0
    [100718.051075]  [<ffffffff8106b79a>] ? warn_slowpath_null+0x1a/0x20
    [100718.051077]  [<ffffffff810747ed>] ? local_bh_enable_ip+0x7d/0xb0
    [100718.051080]  [<ffffffff8150041b>] ? _spin_unlock_bh+0x1b/0x20
    [100718.051085]  [<ffffffffa00ee974>] ? be_process_mcc+0x74/0x230 [be2net]
    [100718.051088]  [<ffffffffa00ea68c>] ? be_poll_tx_mcc+0x16c/0x290 [be2net]
    [100718.051090]  [<ffffffff8144fe76>] ? netpoll_poll_dev+0xd6/0x490
    [100718.051095]  [<ffffffffa01d24a5>] ? bond_poll_controller+0x75/0x80 [bonding]
    [100718.051097]  [<ffffffff8144fde5>] ? netpoll_poll_dev+0x45/0x490
    [100718.051100]  [<ffffffff81161b19>] ? ksize+0x19/0x80
    [100718.051102]  [<ffffffff81450437>] ? netpoll_send_skb_on_dev+0x157/0x240
    
    by reenabling IRQ before calling ->poll, but it seems more
    problems are introduced after that patch:
    
    http://ozlabs.org/~akpm/stuff/IMG_20120824_122054.jpg
    http://marc.info/?l=linux-netdev&m=134563282530588&w=2
    
    So it is safe to fix be2net driver code directly.
    
    This patch reverts the offending commit and fixes be_poll() by
    avoid disabling BH there, this is okay because be_poll()
    can be called either by poll_napi() which already disables
    IRQ, or by net_rx_action() which already disables BH.
    Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Reported-by: default avatarSylvain Munaut <s.munaut@whatever-company.com>
    Cc: Sylvain Munaut <s.munaut@whatever-company.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: David Miller <davem@davemloft.net>
    Cc: Sathya Perla <sathya.perla@emulex.com>
    Cc: Subbu Seetharaman <subbu.seetharaman@emulex.com>
    Cc: Ajit Khaparde <ajit.khaparde@emulex.com>
    Signed-off-by: default avatarCong Wang <amwang@redhat.com>
    Tested-by: default avatarSylvain Munaut <s.munaut@whatever-company.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    072a9c48
netpoll.c 22.3 KB