(This is *NOT* new with 2.6.18-rc1-mm1, I've seen it a few times before, no idea when it started... I think I've seen it as far back as 2.6.16-mm2 or so). Most of the time, the VPN comes up just fine. Jul 10 22:44:28 turing-police kernel: [ 7180.696000] CSLIP: code copyright 1989 Regents of the University of California Jul 10 22:44:28 turing-police kernel: [ 7180.701000] PPP generic driver version 2.4.2 Jul 10 23:00:26 turing-police kernel: [ 8137.903000] PPP MPPE Compression module registered However, sometimes (usually when restarting after the VPN gets dropped due to a network burp, etc), it will start up, get connected, and then the the first (or one of the first) data packets over the VPN will suddenly spike the CPU to 100% (about 50% userspace and 50% kernel). A quick oprofile check shows the kernel CPU getting sucked: samples % image name app name symbol name 10901 18.2805 arc4.ko arc4 .text 5046 8.4619 ppp_async.ko ppp_async ppp_async_push 4865 8.1584 pptp pptp (no symbols) 4382 7.3484 arc4.ko arc4 arc4_set_key 4331 7.2629 vmlinux vmlinux sha_transform 4203 7.0482 libfb.so libfb.so fbCopyAreammx 3342 5.6044 vmlinux vmlinux ecb_process 1324 2.2203 libgdk_imlib.so.1.9.13 libgdk_imlib.so.1.9.13 (no symbols) 1149 1.9268 ip_tables.ko ip_tables ipt_do_table 1071 1.7960 vmlinux vmlinux local_bh_enable 848 1.4221 vmlinux vmlinux acpi_pm_read 816 1.3684 vmlinux vmlinux __local_bh_disable 698 1.1705 vmlinux vmlinux n_tty_receive_buf 651 1.0917 vmlinux vmlinux do_page_fault (pptp is the userspace control process) gkrellm reports that about 4 mbytes/sec is being sent on ppp0 - but shows zero traffic on eth0 (the underlying interface). When working properly, both ppp0 and eth0 show the traffic. This continues until I get fed up and manually take the VPN down, at which point it happily gets rid of ppp0 and CPU load returns to normal. I haven't found a clean way to reproduce it - sometimes I won't see it for 2-3 weeks, then it will pop up several times in an evening. Any suggestions/hints (besides rebuilding the implicated .ko with debugging symbols so oprofile can be more granular - that's already on the to-do list)?
Attachment:
pgpKnnHfVdVAH.pgp
Description: PGP signature
- Follow-Ups:
- Re: 2.6.18-rc1-mm1 - VPN chewing CPU like crazy..
- From: Andrew Morton <[email protected]>
- Re: 2.6.18-rc1-mm1 - VPN chewing CPU like crazy..
- Prev by Date: Re: [PATCH] sysctl: Allow /proc/sys without sys_sysctl
- Next by Date: Re: [Fastboot] [PATCH 1/3] stack overflow safe kdump (2.6.18-rc1-i386) - safe_smp_processor_id
- Previous by thread: areca-raid-linux-scsi-driver-update7-fix-3.patch
- Next by thread: Re: 2.6.18-rc1-mm1 - VPN chewing CPU like crazy..
- Index(es):
 |