2011-10-18 Andi Kleen <ak@linux.intel.com>
+ * ggc-page (release_pages): First free large continuous
+ chunks in the madvise path.
+
+2011-10-18 Andi Kleen <ak@linux.intel.com>
+
* ggc-page.c (alloc_pages): Always round up entry_size.
2011-10-19 Andi Kleen <ak@linux.intel.com>
page_entry *p, *start_p;
char *start;
size_t len;
+ size_t mapped_len;
+ page_entry *next, *prev, *newprev;
+ size_t free_unit = (GGC_QUIRE_SIZE/2) * G.pagesize;
+
+ /* First free larger continuous areas to the OS.
+ This allows other allocators to grab these areas if needed.
+ This is only done on larger chunks to avoid fragmentation.
+ This does not always work because the free_pages list is only
+ approximately sorted. */
+
+ p = G.free_pages;
+ prev = NULL;
+ while (p)
+ {
+ start = p->page;
+ start_p = p;
+ len = 0;
+ mapped_len = 0;
+ newprev = prev;
+ while (p && p->page == start + len)
+ {
+ len += p->bytes;
+ if (!p->discarded)
+ mapped_len += p->bytes;
+ newprev = p;
+ p = p->next;
+ }
+ if (len >= free_unit)
+ {
+ while (start_p != p)
+ {
+ next = start_p->next;
+ free (start_p);
+ start_p = next;
+ }
+ munmap (start, len);
+ if (prev)
+ prev->next = p;
+ else
+ G.free_pages = p;
+ G.bytes_mapped -= mapped_len;
+ continue;
+ }
+ prev = newprev;
+ }
+
+ /* Now give back the fragmented pages to the OS, but keep the address
+ space to reuse it next time. */
for (p = G.free_pages; p; )
{