Server hung or hung_task panic, blocked task waiting on a read of a memory page
Issue
- Server is hung and/or hung_task panic was tripped, and oldest blocked task(s) are seen in a read() system call, ending up in
sync_page -> io_schedule
- Blocked task with backtrace similar to the following. What does this mean and what are the next steps?
Call Trace:
[<ffffffff800637de>] io_schedule+0x3f/0x67
[<ffffffff80028bf0>] sync_page+0x3e/0x43
[<ffffffff80063922>] __wait_on_bit_lock+0x36/0x66
[<ffffffff8003f980>] __lock_page+0x5e/0x64
[<ffffffff8000c425>] do_generic_mapping_read+0x1df/0x359
[<ffffffff8000c6eb>] __generic_file_aio_read+0x14c/0x198
[<ffffffff800c9eca>] generic_file_read+0xac/0xc5
[<ffffffff8000b721>] vfs_read+0xcb/0x171
[<ffffffff80011d15>] sys_read+0x45/0x6e
[<ffffffff8005d28d>] tracesys+0xd5/0xe0
Environment
- Red Hat Enterprise Linux 5
- any process doing reads to any filesystem
Subscriber exclusive content
A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.