Date: Sun, 22 Jul 2007 16:27:42 -0500 From: Eric Anderson <anderson@freebsd.org> To: freebsd-current@freebsd.org, gurney_j@resnet.uoregon.edu Subject: Re: processes stuck in kqread Message-ID: <46A3CBCE.3000300@freebsd.org> In-Reply-To: <20070722001514.GB1221@funkthat.com> References: <469E3B7C.4020402@centtech.com> <20070722001514.GB1221@funkthat.com>
next in thread | previous in thread | raw e-mail | index | archive | help
John-Mark Gurney wrote: > kevin kramer wrote this message on Wed, Jul 18, 2007 at 11:10 -0500: >> I have been having issues for some time on -CURRENT. My latest update >> was 7/11. I have identified these processes as being stuck in kqread >> while waiting for them to continue. >> >> Processes that I know are a problem: >> sshd - I can watch a login and the process goes from Select to kqread, >> takes about 3-4 minutes to get a login prompt >> top - takes about 2-3 minutes to come up >> tar - never really even starts to read data in and stays in kqread >> >> Processes not affected: >> scp >> gstat >> cvsup >> make >> >> This machine is running AMD64 GENERIC kernel on a Dual-Core Xeons. >> dmesg.txt and top-trace.txt here, http://users.centtech.com/~kramer/snapshot >> >> What do I do to debug this? > > running the process under ktrace would help identify what it is waiting > for... Though if it usually hangs for a minute or two in kqread, and > then continues, it's probably a DNS lookup issue... > You mean like the one he put here: http://users.centtech.com/~kramer/snapshot/top-trace.txt :) A quick snippet: 84667 top 0.006110 RET sendto 56/0x38 84667 top 0.006128 CALL kevent(0x6,0x800c11910,0x1,0x7fffffffdad0,0x1,0x7fffffffdb10) 84667 top 5.008057 GIO fd 6 wrote 32 bytes 0x0000 0500 0000 0000 0000 ffff 0100 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 |................................| 84667 top 5.008073 GIO fd 6 read 0 bytes "" 84667 top 5.008078 RET kevent 0 84667 top 5.008086 CALL gettimeofday(0x7fffffffdb20,0) 84667 top 5.008091 RET gettimeofday 0 84667 top 5.008096 CALL sendto(0x5,0x800c11ac4,0x38,0,0x800c11808,0x10) 84667 top 5.008139 GIO fd 5 wrote 56 bytes 0x0000 4696 2a64 0000 0000 0000 0002 0001 86a0 0000 0002 0000 0003 0000 0000 0000 0000 0000 0000 0000 0000 |F.*d....................................| 0x0028 0001 86a7 0000 0002 0000 0006 0000 0000 |................| 84667 top 5.008155 RET sendto 56/0x38 84667 top 5.008163 CALL kevent(0x6,0x800c11910,0,0x7fffffffdad0,0x1,0x7fffffffdb10) 84667 top 15.007883 GIO fd 6 wrote 0 bytes "" Eric
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?46A3CBCE.3000300>