Attachment 925192 Details for Bug 1128200 – sketch of a patch to fix this performance issue

[patch] sketch of a patch to fix this performance issue

procps-ps-selection-by-pid.patch (text/plain), 2.95 KB, created by Arthur Nascimento on 2014-08-08 14:47:56 UTC

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Creator: Arthur Nascimento

Created: 2014-08-08 14:47:56 UTC

Size: 2.95 KB

patch

obsolete

>--- procps-3.2.7-a/ps/display.c	2014-08-07 21:30:58.000000000 -0300
>+++ procps-3.2.7-c/ps/display.c	2014-08-07 23:03:10.000000000 -0300
>@@ -202,6 +202,31 @@
>   return needs;
> }
> 
>+
>+/***** compare function for qsort on pid_t */
>+static int compare_two_pid_t(const void *a, const void *b){
>+  pid_t A = *((pid_t *) a);
>+  pid_t B = *((pid_t *) b);
>+  if (A < B)
>+    return -1;
>+  if (A > B)
>+    return 1;
>+  return 0;
>+}
>+
>+/***** set the selection method */
>+/* 0 to iterate through all /proc and PROC_PID to iterate through a pid_t list*/
>+static unsigned set_selection_method(selection_node * walk){
>+  if (all_processes || simple_select || !walk)
>+    return 0;
>+  while(walk){
>+    if (walk->typecode != SEL_PID)
>+      return 0;
>+	walk = walk->next;
>+  }
>+  return PROC_PID;
>+}
>+
> /***** check needs */
> /* see what files need to be read, etc. */
> static unsigned collect_format_needs(format_node *walk){
>@@ -215,9 +240,11 @@
> 
> static format_node *proc_format_list;
> static format_node *task_format_list;
>+static pid_t *pids = NULL;
> 
> static unsigned needs_for_threads;
> static unsigned needs_for_sort;
>+static unsigned selection_method;
> static unsigned proc_format_needs;
> static unsigned task_format_needs;
> 
>@@ -274,6 +301,35 @@
> 
>   needs_for_sort = check_sort_needs(sort_list);
> 
>+  selection_method = set_selection_method(selection_list);
>+  if (selection_method) {
>+    /* count pids provided + 1 */
>+    int count = 1, pos = 0, i;
>+    selection_node *p = selection_list;
>+    while (p) {
>+      if (p->typecode == SEL_PID)
>+        count += p->n;
>+      p = p->next;
>+    }
>+    pids = (pid_t *) malloc(count * sizeof(pid_t));
>+    p = selection_list;
>+    while (p) {
>+      if (p->typecode == SEL_PID) {
>+        for (i = 0; i < p->n; i++)
>+          pids[pos++] = p->u[i].pid;
>+      }
>+      p = p->next;
>+    }
>+    pids[pos] = (pid_t) 0;
>+    qsort(pids, count - 1, sizeof(pid_t), compare_two_pid_t);
>+    for (pos = 0, i = 1; i < count - 1; i++) {
>+      if (pids[pos] != pids[i])
>+        pos++;
>+      pids[pos] = pids[i];
>+    }
>+    pids[pos+1] = 0;
>+  }
>+
>   // move process-only flags to the process
>   proc_format_needs |= (task_format_needs &~ PROC_ONLY_FLAGS);
>   task_format_needs &= ~PROC_ONLY_FLAGS;
>@@ -328,7 +384,8 @@
> static void simple_spew(void){
>   proc_t buf;
>   PROCTAB* ptp;
>-  ptp = openproc(needs_for_format | needs_for_sort | needs_for_select | needs_for_threads);
>+
>+  ptp = openproc(needs_for_format | needs_for_sort | needs_for_select | needs_for_threads | selection_method, pids);
>   if(!ptp) {
>     fprintf(stderr, "Error: can not access /proc.\n");
>     exit(1);
>@@ -520,7 +577,7 @@
>   PROCTAB *restrict ptp;
>   int n = 0;  /* number of processes & index into array */
> 
>-  ptp = openproc(needs_for_format | needs_for_sort | needs_for_select | needs_for_threads);
>+  ptp = openproc(needs_for_format | needs_for_sort | needs_for_select | needs_for_threads | selection_method, pids);
>   if(!ptp) {
>     fprintf(stderr, "Error: can not access /proc.\n");
>     exit(1);

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Attachments on bug 1128200: 925191 | 925192