Re: [PATCH v3 01/15] x86/dumpstack: Optimize save_stack_trace

2016-09-13 Thread Byungchul Park
On Tue, Sep 13, 2016 at 10:18 PM, Josh Poimboeuf wrote: > On Tue, Sep 13, 2016 at 06:45:00PM +0900, Byungchul Park wrote: >> Currently, x86 implementation of save_stack_trace() is walking all stack >> region word by word regardless of what the trace->max_entries is. >> However, it's unnecessary to

Re: [PATCH v3 01/15] x86/dumpstack: Optimize save_stack_trace

2016-09-13 Thread Josh Poimboeuf
On Tue, Sep 13, 2016 at 06:45:00PM +0900, Byungchul Park wrote: > Currently, x86 implementation of save_stack_trace() is walking all stack > region word by word regardless of what the trace->max_entries is. > However, it's unnecessary to walk after already fulfilling caller's > requirement, say, if

[PATCH v3 01/15] x86/dumpstack: Optimize save_stack_trace

2016-09-13 Thread Byungchul Park
Currently, x86 implementation of save_stack_trace() is walking all stack region word by word regardless of what the trace->max_entries is. However, it's unnecessary to walk after already fulfilling caller's requirement, say, if trace->nr_entries >= trace->max_entries is true. I measured its overhe