From: Frederic Weisbecker Date: Thu, 31 Dec 2009 04:53:02 +0000 (+0100) Subject: perf: Pass appropriate frame pointer to dump_trace() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=48b5ba9cc98d676712da29d9931f1c88e5185ff2;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git perf: Pass appropriate frame pointer to dump_trace() Pass the frame pointer from the regs of the interrupted path to dump_trace() while processing the stack trace. Currently, dump_trace() takes the current bp and starts the callchain from dump_trace() itself. This is wasteful because we need to walk through the entire NMI/DEBUG stack before retrieving the interrupted point. We can fix that by just using the frame pointer from the captured regs. It points exactly where we want to start. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras LKML-Reference: <1262235183-5320-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras --- diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index c223b7e895d..d616c06e99b 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -2347,7 +2347,7 @@ perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) callchain_store(entry, PERF_CONTEXT_KERNEL); callchain_store(entry, regs->ip); - dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); + dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry); } /*