forked from luck/tmp_suning_uos_patched
7519ece673
[ Upstream commit 78cf0eb926cb1abeff2106bae67752e032fe5f3e ]
When update the latest mainline kernel with the following three configs,
the kernel hangs during startup:
(1) CONFIG_FUNCTION_GRAPH_TRACER=y
(2) CONFIG_PREEMPT_TRACER=y
(3) CONFIG_FTRACE_STARTUP_TEST=y
When update the latest mainline kernel with the above two configs (1)
and (2), the kernel starts normally, but it still hangs when execute
the following command:
echo "function_graph" > /sys/kernel/debug/tracing/current_tracer
Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs
disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences
with function_graph tracer at the first glance.
I use ejtag to find out the epc address is related with preempt_enable()
in the file arch/mips/lib/mips-atomic.c, because function tracing can
trace the preempt_{enable,disable} calls that are traced, replace them
with preempt_{enable,disable}_notrace to prevent function tracing from
going into an infinite loop, and then it can fix the kernel hang issue.
By the way, it seems that this commit is a complement and improvement of
commit
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| .. | ||
| bitops.c | ||
| bswapdi.c | ||
| bswapsi.c | ||
| csum_partial.S | ||
| delay.c | ||
| dump_tlb.c | ||
| iomap_copy.c | ||
| iomap-pci.c | ||
| libgcc.h | ||
| Makefile | ||
| memcpy.S | ||
| memset.S | ||
| mips-atomic.c | ||
| multi3.c | ||
| r3k_dump_tlb.c | ||
| strncpy_user.S | ||
| strnlen_user.S | ||
| uncached.c | ||