On Thu, 22 Mar 2018, Steven Rostedt wrote: > > The trace event trace_mm_vmscan_lru_shrink_inactive() currently has 12 > parameters! Seven of them are from the reclaim_stat structure. This > structure is currently local to mm/vmscan.c. By moving it to the global > vmstat.h header, we can also reference it from the vmscan tracepoints. In > moving it, it brings down the overhead of passing so many arguments to the > trace event. In the future, we may limit the number of arguments that a > trace event may pass (ideally just 6, but more realistically it may be 8). > > Before this patch, the code to call the trace event is this: > > 0f 83 aa fe ff ff jae ffffffff811e6261 <shrink_inactive_list+0x1e1> > 48 8b 45 a0 mov -0x60(%rbp),%rax > 45 8b 64 24 20 mov 0x20(%r12),%r12d > 44 8b 6d d4 mov -0x2c(%rbp),%r13d > 8b 4d d0 mov -0x30(%rbp),%ecx > 44 8b 75 cc mov -0x34(%rbp),%r14d > 44 8b 7d c8 mov -0x38(%rbp),%r15d > 48 89 45 90 mov %rax,-0x70(%rbp) > 8b 83 b8 fe ff ff mov -0x148(%rbx),%eax > 8b 55 c0 mov -0x40(%rbp),%edx > 8b 7d c4 mov -0x3c(%rbp),%edi > 8b 75 b8 mov -0x48(%rbp),%esi > 89 45 80 mov %eax,-0x80(%rbp) > 65 ff 05 e4 f7 e2 7e incl %gs:0x7ee2f7e4(%rip) # 15bd0 <__preempt_count> > 48 8b 05 75 5b 13 01 mov 0x1135b75(%rip),%rax # ffffffff8231bf68 <__tracepoint_mm_vmscan_lru_shrink_inactive+0x28> > 48 85 c0 test %rax,%rax > 74 72 je ffffffff811e646a <shrink_inactive_list+0x3ea> > 48 89 c3 mov %rax,%rbx > 4c 8b 10 mov (%rax),%r10 > 89 f8 mov %edi,%eax > 48 89 85 68 ff ff ff mov %rax,-0x98(%rbp) > 89 f0 mov %esi,%eax > 48 89 85 60 ff ff ff mov %rax,-0xa0(%rbp) > 89 c8 mov %ecx,%eax > 48 89 85 78 ff ff ff mov %rax,-0x88(%rbp) > 89 d0 mov %edx,%eax > 48 89 85 70 ff ff ff mov %rax,-0x90(%rbp) > 8b 45 8c mov -0x74(%rbp),%eax > 48 8b 7b 08 mov 0x8(%rbx),%rdi > 48 83 c3 18 add $0x18,%rbx > 50 push %rax > 41 54 push %r12 > 41 55 push %r13 > ff b5 78 ff ff ff pushq -0x88(%rbp) > 41 56 push %r14 > 41 57 push %r15 > ff b5 70 ff ff ff pushq -0x90(%rbp) > 4c 8b 8d 68 ff ff ff mov -0x98(%rbp),%r9 > 4c 8b 85 60 ff ff ff mov -0xa0(%rbp),%r8 > 48 8b 4d 98 mov -0x68(%rbp),%rcx > 48 8b 55 90 mov -0x70(%rbp),%rdx > 8b 75 80 mov -0x80(%rbp),%esi > 41 ff d2 callq *%r10 > > After the patch: > > 0f 83 a8 fe ff ff jae ffffffff811e626d <shrink_inactive_list+0x1cd> > 8b 9b b8 fe ff ff mov -0x148(%rbx),%ebx > 45 8b 64 24 20 mov 0x20(%r12),%r12d > 4c 8b 6d a0 mov -0x60(%rbp),%r13 > 65 ff 05 f5 f7 e2 7e incl %gs:0x7ee2f7f5(%rip) # 15bd0 <__preempt_count> > 4c 8b 35 86 5b 13 01 mov 0x1135b86(%rip),%r14 # ffffffff8231bf68 <__tracepoint_mm_vmscan_lru_shrink_inactive+0x28> > 4d 85 f6 test %r14,%r14 > 74 2a je ffffffff811e6411 <shrink_inactive_list+0x371> > 49 8b 06 mov (%r14),%rax > 8b 4d 8c mov -0x74(%rbp),%ecx > 49 8b 7e 08 mov 0x8(%r14),%rdi > 49 83 c6 18 add $0x18,%r14 > 4c 89 ea mov %r13,%rdx > 45 89 e1 mov %r12d,%r9d > 4c 8d 45 b8 lea -0x48(%rbp),%r8 > 89 de mov %ebx,%esi > 51 push %rcx > 48 8b 4d 98 mov -0x68(%rbp),%rcx > ff d0 callq *%rax > > Link: http://lkml.kernel.org/r/2559d7cb-ec60-1200-2362-04fa34fd02bb@xxxxxx > > Reported-by: Alexei Starovoitov <ast@xxxxxx> > Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
