• Steven Rostedt's avatar
    mm, vmscan, tracing: use pointer to reclaim_stat struct in trace event · d51d1e64
    Steven Rostedt authored
    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@fb.com
    Link: http://lkml.kernel.org/r/20180322121003.4177af15@gandalf.local.homeSigned-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
    Reported-by: default avatarAlexei Starovoitov <ast@fb.com>
    Acked-by: default avatarDavid Rientjes <rientjes@google.com>
    Acked-by: default avatarMichal Hocko <mhocko@suse.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Vlastimil Babka <vbabka@suse.cz>
    Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
    Cc: Alexei Starovoitov <ast@fb.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    d51d1e64
vmscan.h 12.2 KB