Jason Baron
2de359062f
[ Upstream commit 92ee46efeb ]
Fengguang Wu reported that running the rcuperf test during boot can cause
the jump_label_test() to hit a WARN_ON(). The issue is that the core jump
label code relies on kernel_text_address() to detect when it can no longer
update branches that may be contained in __init sections. The
kernel_text_address() in turn assumes that if the system_state variable is
greter than or equal to SYSTEM_RUNNING then __init sections are no longer
valid (since the assumption is that they have been freed). However, when
rcuperf is setup to run in early boot it can call kernel_power_off() which
sets the system_state to SYSTEM_POWER_OFF.
Since rcuperf initialization is invoked via a module_init(), we can make
the dependency of jump_label_test() needing to complete before rcuperf
explicit by calling it via early_initcall().
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1510609727-2238-1-git-send-email-jbaron@akamai.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.