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path: root/drivers/android/binder_alloc.c
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Diffstat (limited to 'drivers/android/binder_alloc.c')
-rw-r--r--drivers/android/binder_alloc.c172
1 files changed, 149 insertions, 23 deletions
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index e96659215f25..11a08bf72bcc 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -27,9 +27,12 @@
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/list_lru.h>
#include "binder_alloc.h"
#include "binder_trace.h"
+struct list_lru binder_alloc_lru;
+
static DEFINE_MUTEX(binder_alloc_mmap_lock);
enum {
@@ -188,8 +191,9 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
{
void *page_addr;
unsigned long user_page_addr;
- struct page **page;
- struct mm_struct *mm;
+ struct binder_lru_page *page;
+ struct mm_struct *mm = NULL;
+ bool need_mm = false;
binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
"%d: %s pages %pK-%pK\n", alloc->pid,
@@ -200,9 +204,18 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
trace_binder_update_page_range(alloc, allocate, start, end);
- if (vma)
- mm = NULL;
- else
+ if (allocate == 0)
+ goto free_range;
+
+ for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
+ page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
+ if (!page->page_ptr) {
+ need_mm = true;
+ break;
+ }
+ }
+
+ if (!vma && need_mm)
mm = get_task_mm(alloc->tsk);
if (mm) {
@@ -215,10 +228,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
}
- if (allocate == 0)
- goto free_range;
-
- if (vma == NULL) {
+ if (!vma && need_mm) {
pr_err("%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
alloc->pid);
goto err_no_vma;
@@ -226,18 +236,33 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
int ret;
+ bool on_lru;
page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
- BUG_ON(*page);
- *page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
- if (*page == NULL) {
+ if (page->page_ptr) {
+ on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
+ WARN_ON(!on_lru);
+ continue;
+ }
+
+ if (WARN_ON(!vma))
+ goto err_page_ptr_cleared;
+
+ page->page_ptr = alloc_page(GFP_KERNEL |
+ __GFP_HIGHMEM |
+ __GFP_ZERO);
+ if (!page->page_ptr) {
pr_err("%d: binder_alloc_buf failed for page at %pK\n",
alloc->pid, page_addr);
goto err_alloc_page_failed;
}
+ page->alloc = alloc;
+ INIT_LIST_HEAD(&page->lru);
+
ret = map_kernel_range_noflush((unsigned long)page_addr,
- PAGE_SIZE, PAGE_KERNEL, page);
+ PAGE_SIZE, PAGE_KERNEL,
+ &page->page_ptr);
flush_cache_vmap((unsigned long)page_addr,
(unsigned long)page_addr + PAGE_SIZE);
if (ret != 1) {
@@ -247,7 +272,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
}
user_page_addr =
(uintptr_t)page_addr + alloc->user_buffer_offset;
- ret = vm_insert_page(vma, user_page_addr, page[0]);
+ ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
if (ret) {
pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n",
alloc->pid, user_page_addr);
@@ -264,16 +289,21 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
free_range:
for (page_addr = end - PAGE_SIZE; page_addr >= start;
page_addr -= PAGE_SIZE) {
+ bool ret;
+
page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE];
- if (vma)
- zap_page_range(vma, (uintptr_t)page_addr +
- alloc->user_buffer_offset, PAGE_SIZE);
+
+ ret = list_lru_add(&binder_alloc_lru, &page->lru);
+ WARN_ON(!ret);
+ continue;
+
err_vm_insert_page_failed:
unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
err_map_kernel_failed:
- __free_page(*page);
- *page = NULL;
+ __free_page(page->page_ptr);
+ page->page_ptr = NULL;
err_alloc_page_failed:
+err_page_ptr_cleared:
;
}
err_no_vma:
@@ -731,16 +761,20 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
void *page_addr;
+ bool on_lru;
- if (!alloc->pages[i])
+ if (!alloc->pages[i].page_ptr)
continue;
+ on_lru = list_lru_del(&binder_alloc_lru,
+ &alloc->pages[i].lru);
page_addr = alloc->buffer + i * PAGE_SIZE;
binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
- "%s: %d: page %d at %pK not freed\n",
- __func__, alloc->pid, i, page_addr);
+ "%s: %d: page %d at %pK %s\n",
+ __func__, alloc->pid, i, page_addr,
+ on_lru ? "on lru" : "active");
unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
- __free_page(alloc->pages[i]);
+ __free_page(alloc->pages[i].page_ptr);
page_count++;
}
kfree(alloc->pages);
@@ -817,6 +851,93 @@ void binder_alloc_vma_close(struct binder_alloc *alloc)
}
/**
+ * binder_alloc_free_page() - shrinker callback to free pages
+ * @item: item to free
+ * @lock: lock protecting the item
+ * @cb_arg: callback argument
+ *
+ * Called from list_lru_walk() in binder_shrink_scan() to free
+ * up pages when the system is under memory pressure.
+ */
+enum lru_status binder_alloc_free_page(struct list_head *item,
+ struct list_lru_one *lru,
+ spinlock_t *lock,
+ void *cb_arg)
+{
+ struct mm_struct *mm = NULL;
+ struct binder_lru_page *page = container_of(item,
+ struct binder_lru_page,
+ lru);
+ struct binder_alloc *alloc;
+ uintptr_t page_addr;
+ size_t index;
+
+ alloc = page->alloc;
+ if (!mutex_trylock(&alloc->mutex))
+ goto err_get_alloc_mutex_failed;
+
+ if (!page->page_ptr)
+ goto err_page_already_freed;
+
+ index = page - alloc->pages;
+ page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
+ if (alloc->vma) {
+ mm = get_task_mm(alloc->tsk);
+ if (!mm)
+ goto err_get_task_mm_failed;
+ if (!down_write_trylock(&mm->mmap_sem))
+ goto err_down_write_mmap_sem_failed;
+
+ zap_page_range(alloc->vma,
+ page_addr + alloc->user_buffer_offset,
+ PAGE_SIZE);
+
+ up_write(&mm->mmap_sem);
+ mmput(mm);
+ }
+
+ unmap_kernel_range(page_addr, PAGE_SIZE);
+ __free_page(page->page_ptr);
+ page->page_ptr = NULL;
+
+ list_lru_isolate(lru, item);
+
+ mutex_unlock(&alloc->mutex);
+ return LRU_REMOVED;
+
+err_down_write_mmap_sem_failed:
+ mmput(mm);
+err_get_task_mm_failed:
+err_page_already_freed:
+ mutex_unlock(&alloc->mutex);
+err_get_alloc_mutex_failed:
+ return LRU_SKIP;
+}
+
+static unsigned long
+binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ unsigned long ret = list_lru_count(&binder_alloc_lru);
+ return ret;
+}
+
+static unsigned long
+binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ unsigned long ret;
+
+ ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
+ NULL, sc->nr_to_scan);
+ return ret;
+}
+
+struct shrinker binder_shrinker = {
+ .count_objects = binder_shrink_count,
+ .scan_objects = binder_shrink_scan,
+ .seeks = DEFAULT_SEEKS,
+};
+
+/**
* binder_alloc_init() - called by binder_open() for per-proc initialization
* @alloc: binder_alloc for this proc
*
@@ -830,3 +951,8 @@ void binder_alloc_init(struct binder_alloc *alloc)
mutex_init(&alloc->mutex);
}
+void binder_alloc_shrinker_init(void)
+{
+ list_lru_init(&binder_alloc_lru);
+ register_shrinker(&binder_shrinker);
+}

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