page allocation failure.问题
最近ubuntu系统总是死机，查日志如下
Apr 15 01:00:35 zz008 — MARK –
Apr 15 01:14:03 zz008 kernel: [76358.620322] swapper: page allocation failure. order:0, mode:0×4020
Apr 15 01:25:09 zz008 kernel: [76358.620339] Pid: 0, comm: swapper Not tainted 2.6.27-7-server #1
google了一下，估计是如下问题，备考。
可以加大 kernel 預留的 Buffer, 我系統上原來是 2878, 可以用指令
改为8兆即
8192
echo 8192 > /proc/sys/vm/min_free_kbytes
加大到 8Mbytes, 这样可以减少 page allocation 失败概率（原来是每2~3天）, 在测试时间, 某些時候 8MByte 可能还会出現上述问题, 可以考虑加大到 16Mbytes.
原因是因為在 interrupt 中, 向系統一次要求大块的内存时因碎片等出现问题. 這時可以通过增加 min_free_kbytes 参数去避开這個问题。
btw，
調整 slab 的参数或許也有用 ( echo x y z > /proc/slab)
参考：
http://lime-technology.com/forum/index.php?topic=3999.0
http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-01/0059.html
实际操作发现任然没有解决此问题
网上找到是内核和网卡打架造成解决如下：
The Hardy Heron kernel was recently uploaded for testing. We’d really appreciate it if you could try testing with this newer kernel and verify if this issue still exists. Unfortunately, the Hardy Heron Alpha1 LiveCD was released with the older 2.6.22 kernel. You’ll have to manually install the newer Hardy Heron kernel in order to test. This should not be the case for Alpha2 which is set to come out around Dec 20. However, here are the instructions to install if you choose to do so, otherwise just wait for Alpha2 to come out:
1) 编辑ubuntu中的文件/etc/apt/sources.list 在里面添加下面的一行内容:
deb http://archive.ubuntu.com/ubuntu hardy main restricted
接着操作就简单了，就是装一下新内核补了
2) sudo apt-get update
3) sudo apt-get dist-upgrade
4) reboot and select the new kernel from the grub menu
After you’ve tested, please feel free to revert back – ie boot into the old kernel, sudo apt-get remove linux-image-2.6.24-1-generic, and remove the line from /etc/apt/sources.list . Please update this report with your results. Thanks in advance!
Changed in linux:
importance:
Undecided → Medium
status:
New → Incomplete
