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| author | Eric Dumazet | 2012-01-03 01:00:11 +0100 |
|---|---|---|
| committer | David S. Miller | 2012-01-03 19:03:20 +0100 |
| commit | fa0f5aa74316c636427ac92dad0bc5714c34ca17 (patch) | |
| tree | 64fcb6a7f4043cdaea4a13b730a1ca651190e314 /drivers/net/ethernet/ti/davinci_emac.c | |
| parent | sch_qfq: accurate wsum handling (diff) | |
| download | kernel-qcow2-linux-fa0f5aa74316c636427ac92dad0bc5714c34ca17.tar.gz kernel-qcow2-linux-fa0f5aa74316c636427ac92dad0bc5714c34ca17.tar.xz kernel-qcow2-linux-fa0f5aa74316c636427ac92dad0bc5714c34ca17.zip | |
net_sched: qdisc_alloc_handle() can be too slow
When trying to allocate ~32768 qdiscs using autohandle mechanism, we can
fill the space managed by kernel (handles in [8000-FFFF]:0000 range)
But O(N^2) qdisc_alloc_handle() loops 0x10000 times instead of 0x8000
time tc add qdisc add dev eth0 parent 10:7fff pfifo limit 10
RTNETLINK answers: Cannot allocate memory
real 1m54.826s
user 0m0.000s
sys 0m0.004s
INFO: rcu_sched_state detected stall on CPU 0 (t=60000 jiffies)
Half number of loops, and add a cond_resched() call.
We hold rtnl at this point.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Dave Taht <dave.taht@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/ti/davinci_emac.c')
0 files changed, 0 insertions, 0 deletions