From: Steven Rostedt (Red Hat) Date: Thu, 14 Mar 2013 03:34:22 +0000 (-0400) Subject: tracing: Remove most or all of stack tracer stack size from stack_max_size X-Git-Tag: v3.2.45~114 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cde591b5c0694768bfbafe3f3ca32e2c20c5ebfe;p=pandora-kernel.git tracing: Remove most or all of stack tracer stack size from stack_max_size commit 4df297129f622bdc18935c856f42b9ddd18f9f28 upstream. Currently, the depth reported in the stack tracer stack_trace file does not match the stack_max_size file. This is because the stack_max_size includes the overhead of stack tracer itself while the depth does not. The first time a max is triggered, a calculation is not performed that figures out the overhead of the stack tracer and subtracts it from the stack_max_size variable. The overhead is stored and is subtracted from the reported stack size for comparing for a new max. Now the stack_max_size corresponds to the reported depth: # cat stack_max_size 4640 # cat stack_trace Depth Size Location (48 entries) ----- ---- -------- 0) 4640 32 _raw_spin_lock+0x18/0x24 1) 4608 112 ____cache_alloc+0xb7/0x22d 2) 4496 80 kmem_cache_alloc+0x63/0x12f 3) 4416 16 mempool_alloc_slab+0x15/0x17 [...] While testing against and older gcc on x86 that uses mcount instead of fentry, I found that pasing in ip + MCOUNT_INSN_SIZE let the stack trace show one more function deep which was missing before. Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed