Manjunath Patil
96d9cbe2f2
Add timeout to cm_destroy_id, so that userspace can trigger any data collection that would help in analyzing the cause of delay in destroying the cm_id. New noinline function helps dtrace/ebpf programs to hook on to it. Existing functionality isn't changed except triggering a probe-able new function at every timeout interval. We have seen cases where CM messages stuck with MAD layer (either due to software bug or faulty HCA), leading to cm_id getting stuck in the following call stack. This patch helps in resolving such issues faster. kernel: ... INFO: task XXXX:56778 blocked for more than 120 seconds. ... Call Trace: __schedule+0x2bc/0x895 schedule+0x36/0x7c schedule_timeout+0x1f6/0x31f ? __slab_free+0x19c/0x2ba wait_for_completion+0x12b/0x18a ? wake_up_q+0x80/0x73 cm_destroy_id+0x345/0x610 [ib_cm] ib_destroy_cm_id+0x10/0x20 [ib_cm] rdma_destroy_id+0xa8/0x300 [rdma_cm] ucma_destroy_id+0x13e/0x190 [rdma_ucm] ucma_write+0xe0/0x160 [rdma_ucm] __vfs_write+0x3a/0x16d vfs_write+0xb2/0x1a1 ? syscall_trace_enter+0x1ce/0x2b8 SyS_write+0x5c/0xd3 do_syscall_64+0x79/0x1b9 entry_SYSCALL_64_after_hwframe+0x16d/0x0 Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com> Link: https://lore.kernel.org/r/20240309063323.458102-1-manjunath.b.patil@oracle.com Signed-off-by: Leon Romanovsky <leon@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.