Re: argv subscript range uses too many memory

[Han Pingtian <hanpt@xxxxxxxxxxxxxxxxxx>]

Hi Bart,

I have tried your suggestion. Looks like this patch on 5.0 resolve both
problem. The for loop of 29175 run about 5 seconds on my loptop and the
while loop only used ~180M memory on my loptop, it does't trigger
oom-killer any more.


diff --git a/Src/mem.c b/Src/mem.c
index 5275c6c..0e4d258 100644
--- a/Src/mem.c
+++ b/Src/mem.c
@@ -106,7 +106,7 @@ union mem_align {
 };
 
 #define H_ISIZE  sizeof(union mem_align)
-#define HEAPSIZE (16384 - H_ISIZE)
+#define HEAPSIZE (163840 - H_ISIZE)
 /* Memory available for user data in default arena size */
 #define HEAP_ARENA_SIZE (HEAPSIZE - sizeof(struct heap))
 #define HEAPFREE (16384 - H_ISIZE)
@@ -319,28 +319,8 @@ freeheap(void)
     h_free++;
 #endif
 
-    /* At this point we used to do:
     fheap = NULL;
-     *
-     * When pushheap() is called, it sweeps over the entire heaps list of
-     * arenas and marks every one of them with the amount of free space in
-     * that arena at that moment.  zhalloc() is then allowed to grab bits
-     * out of any of those arenas that have free space.
-     *
-     * With the above reset of fheap, the loop below sweeps back over the
-     * entire heap list again, resetting the free space in every arena to
-     * the amount stashed by pushheap() and finding the first arena with
-     * free space to optimize zhalloc()'s next search.  When there's a lot
-     * of stuff already on the heap, this is an enormous amount of work,
-     * and performance goes to hell.
-     *
-     * However, there doesn't seem to be any reason to reset fheap before
-     * beginning this loop.  Either it's already correct, or it has never
-     * been set and this loop will do it, or it'll be reset from scratch
-     * on the next popheap().  So all that's needed here is to pick up
-     * the scan wherever the last pass [or the last popheap()] left off.
-     */
-    for (h = (fheap ? fheap : heaps); h; h = hn) {
+    for (h = heaps; h; h = hn) {
 	hn = h->next;
 	if (h->sp) {
 #ifdef ZSH_MEM_DEBUG
@@ -377,7 +357,7 @@ freeheap(void)
     if (hl)
 	hl->next = NULL;
     else
-	heaps = fheap = NULL;
+	heaps = NULL;
 
     unqueue_signals();
 }