lib: remove prio_heap

The prio_heap code is unused since commit 889ed9ceaa97 ("cgroup: remove
css_scan_tasks()").  It should be compiled out to shrink the binary
kernel size which can be done via introducing CONFIG_PRIO_HEAD or by
removing the code.

We can simply recover the code from git when needed, so it would be
better to remove it IMO.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: George Spelvin <linux@horizon.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/prio_heap.h b/include/linux/prio_heap.h
deleted file mode 100644 (file)
index 0809435..0000000
--- a/include/linux/prio_heap.h
+++ /dev/null
@@ -1,58 +0,0 @@
-#ifndef _LINUX_PRIO_HEAP_H
-#define _LINUX_PRIO_HEAP_H
-
-/*
- * Simple insertion-only static-sized priority heap containing
- * pointers, based on CLR, chapter 7
- */
-
-#include <linux/gfp.h>
-
-/**
- * struct ptr_heap - simple static-sized priority heap
- * @ptrs - pointer to data area
- * @max - max number of elements that can be stored in @ptrs
- * @size - current number of valid elements in @ptrs (in the range 0..@size-1
- * @gt: comparison operator, which should implement "greater than"
- */
-struct ptr_heap {
-       void **ptrs;
-       int max;
-       int size;
-       int (*gt)(void *, void *);
-};
-
-/**
- * heap_init - initialize an empty heap with a given memory size
- * @heap: the heap structure to be initialized
- * @size: amount of memory to use in bytes
- * @gfp_mask: mask to pass to kmalloc()
- * @gt: comparison operator, which should implement "greater than"
- */
-extern int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask,
-                    int (*gt)(void *, void *));
-
-/**
- * heap_free - release a heap's storage
- * @heap: the heap structure whose data should be released
- */
-void heap_free(struct ptr_heap *heap);
-
-/**
- * heap_insert - insert a value into the heap and return any overflowed value
- * @heap: the heap to be operated on
- * @p: the pointer to be inserted
- *
- * Attempts to insert the given value into the priority heap. If the
- * heap is full prior to the insertion, then the resulting heap will
- * consist of the smallest @max elements of the original heap and the
- * new element; the greatest element will be removed from the heap and
- * returned. Note that the returned element will be the new element
- * (i.e. no change to the heap) if the new element is greater than all
- * elements currently in the heap.
- */
-extern void *heap_insert(struct ptr_heap *heap, void *p);
-
-
-
-#endif /* _LINUX_PRIO_HEAP_H */

diff --git a/lib/Makefile b/lib/Makefile
index d6b4bc4..eb95e0f 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -11,7 +11,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
         rbtree.o radix-tree.o dump_stack.o timerqueue.o\
         idr.o int_sqrt.o extable.o \
         sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \
-        proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \
+        proportions.o flex_proportions.o ratelimit.o show_mem.o \
         is_single_threaded.o plist.o decompress.o kobject_uevent.o \
         earlycpio.o
 

diff --git a/lib/prio_heap.c b/lib/prio_heap.c
deleted file mode 100644 (file)
index a7af6f8..0000000
--- a/lib/prio_heap.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Simple insertion-only static-sized priority heap containing
- * pointers, based on CLR, chapter 7
- */
-
-#include <linux/slab.h>
-#include <linux/prio_heap.h>
-
-int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask,
-             int (*gt)(void *, void *))
-{
-       heap->ptrs = kmalloc(size, gfp_mask);
-       if (!heap->ptrs)
-               return -ENOMEM;
-       heap->size = 0;
-       heap->max = size / sizeof(void *);
-       heap->gt = gt;
-       return 0;
-}
-
-void heap_free(struct ptr_heap *heap)
-{
-       kfree(heap->ptrs);
-}
-
-void *heap_insert(struct ptr_heap *heap, void *p)
-{
-       void *res;
-       void **ptrs = heap->ptrs;
-       int pos;
-
-       if (heap->size < heap->max) {
-               /* Heap insertion */
-               pos = heap->size++;
-               while (pos > 0 && heap->gt(p, ptrs[(pos-1)/2])) {
-                       ptrs[pos] = ptrs[(pos-1)/2];
-                       pos = (pos-1)/2;
-               }
-               ptrs[pos] = p;
-               return NULL;
-       }
-
-       /* The heap is full, so something will have to be dropped */
-
-       /* If the new pointer is greater than the current max, drop it */
-       if (heap->gt(p, ptrs[0]))
-               return p;
-
-       /* Replace the current max and heapify */
-       res = ptrs[0];
-       ptrs[0] = p;
-       pos = 0;
-
-       while (1) {
-               int left = 2 * pos + 1;
-               int right = 2 * pos + 2;
-               int largest = pos;
-               if (left < heap->size && heap->gt(ptrs[left], p))
-                       largest = left;
-               if (right < heap->size && heap->gt(ptrs[right], ptrs[largest]))
-                       largest = right;
-               if (largest == pos)
-                       break;
-               /* Push p down the heap one level and bump one up */
-               ptrs[pos] = ptrs[largest];
-               ptrs[largest] = p;
-               pos = largest;
-       }
-       return res;
-}