top: do not use previous colleced data wheh "h" toggles threads display

This prevents first update from showing incorrect CPU usage data

function                                             old     new   delta
handle_input                                         620     643     +23

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/procps/top.c b/procps/top.c
index 8fe53324f..5c41e8e10 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -979,6 +979,9 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
                 IF_FEATURE_TOPMEM(&& scan_mask != TOPMEM_MASK)
                 ) {
                         scan_mask ^= PSSCAN_TASKS;
+                        free(prev_hist);
+                        prev_hist = NULL;
+                        prev_hist_count = 0;
                         continue;
                 }
 # endif
@@ -1000,10 +1003,10 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
 #  if ENABLE_FEATURE_TOPMEM
                 if (c == 's') {
                         scan_mask = TOPMEM_MASK;
+                        sort_field = (sort_field + 1) % NUM_SORT_FIELD;
                         free(prev_hist);
                         prev_hist = NULL;
                         prev_hist_count = 0;
-                        sort_field = (sort_field + 1) % NUM_SORT_FIELD;
                         continue;
                 }
 #  endif