top: avoid yet more overhead of accessing /proc/status

After discovering those terrible costs associated with
/proc/status vs. /proc/stat, our library changed so as
to favor the latter if a field could be met by either.

Well, low-and-behold, this top program had chosen some
item enumerators that needlessly caused 'status' to be
accessed when 'statm' could be used instead. And while
top's needs require conversion from pages to KiB, that
is still far less costly than that damn 'status' file.

[ this was found when comparing newlib top against a ]
[ 3.2.8 ancient top since the current master top was ]
[ suffering from the exact same 'status' deficiency. ]

[ and, no way was top-3.2.8 going to beat newlib top ]
[ by 50% - we'll allow only a 1-10% occasional loss! ]

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/top/top.c b/top/top.c
index 6ca3c732d246c0db5b6c7281641c5a251ba68bbd..d29d8f4d64077cd45ecfd596e1235b905cdd4aff 100644 (file)
--- a/top/top.c
+++ b/top/top.c
@@ -1519,21 +1519,21 @@ static struct {
    {     6,     -1,  A_right,    -1,  PIDS_TICS_ALL       },  // ull_int  EU_TME
    {     9,     -1,  A_right,    -1,  PIDS_TICS_ALL       },  // ull_int  EU_TM2
 #ifdef BOOST_PERCNT
-   {     5,     -1,  A_right,    -1,  PIDS_VM_RSS         },  // ul_int   EU_MEM
+   {     5,     -1,  A_right,    -1,  PIDS_MEM_RES        },  // ul_int   EU_MEM
 #else
-   {     4,     -1,  A_right,    -1,  PIDS_VM_RSS         },  // ul_int   EU_MEM,
+   {     4,     -1,  A_right,    -1,  PIDS_MEM_RES        },  // ul_int   EU_MEM,
 #endif
 #ifndef NOBOOST_MEMS
    {     7,  SK_Kb,  A_right,    -1,  PIDS_MEM_VIRT       },  // ul_int   EU_VRT
    {     6,  SK_Kb,  A_right,    -1,  PIDS_VM_SWAP        },  // ul_int   EU_SWP
-   {     6,  SK_Kb,  A_right,    -1,  PIDS_VM_RSS         },  // ul_int   EU_RES
+   {     6,  SK_Kb,  A_right,    -1,  PIDS_MEM_RES        },  // ul_int   EU_RES
    {     6,  SK_Kb,  A_right,    -1,  PIDS_MEM_CODE       },  // ul_int   EU_COD
    {     7,  SK_Kb,  A_right,    -1,  PIDS_MEM_DATA       },  // ul_int   EU_DAT
    {     6,  SK_Kb,  A_right,    -1,  PIDS_MEM_SHR        },  // ul_int   EU_SHR
 #else
    {     5,  SK_Kb,  A_right,    -1,  PIDS_MEM_VIRT       },  // ul_int   EU_VRT
    {     4,  SK_Kb,  A_right,    -1,  PIDS_VM_SWAP        },  // ul_int   EU_SWP
-   {     4,  SK_Kb,  A_right,    -1,  PIDS_VM_RSS         },  // ul_int   EU_RES
+   {     4,  SK_Kb,  A_right,    -1,  PIDS_MEM_RES        },  // ul_int   EU_RES
    {     4,  SK_Kb,  A_right,    -1,  PIDS_MEM_CODE       },  // ul_int   EU_COD
    {     5,  SK_Kb,  A_right,    -1,  PIDS_MEM_DATA       },  // ul_int   EU_DAT
    {     4,  SK_Kb,  A_right,    -1,  PIDS_MEM_SHR        },  // ul_int   EU_SHR