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@@ -62,7 +62,9 @@
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#include <linux/pfn.h>
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#include <linux/rbtree.h>
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#include <linux/slab.h>
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+#include <linux/spinlock.h>
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#include <linux/vmalloc.h>
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+#include <linux/workqueue.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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@@ -80,7 +82,8 @@ struct pcpu_chunk {
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int map_alloc; /* # of map entries allocated */
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int *map; /* allocation map */
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bool immutable; /* no [de]population allowed */
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- struct page *page[]; /* #cpus * UNIT_PAGES */
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+ struct page **page; /* points to page array */
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+ struct page *page_ar[]; /* #cpus * UNIT_PAGES */
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};
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static int pcpu_unit_pages __read_mostly;
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@@ -93,28 +96,42 @@ static size_t pcpu_chunk_struct_size __read_mostly;
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void *pcpu_base_addr __read_mostly;
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EXPORT_SYMBOL_GPL(pcpu_base_addr);
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-/* the size of kernel static area */
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-static int pcpu_static_size __read_mostly;
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+/* optional reserved chunk, only accessible for reserved allocations */
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+static struct pcpu_chunk *pcpu_reserved_chunk;
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+/* offset limit of the reserved chunk */
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+static int pcpu_reserved_chunk_limit;
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/*
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- * One mutex to rule them all.
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- *
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- * The following mutex is grabbed in the outermost public alloc/free
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- * interface functions and released only when the operation is
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- * complete. As such, every function in this file other than the
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- * outermost functions are called under pcpu_mutex.
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- *
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- * It can easily be switched to use spinlock such that only the area
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- * allocation and page population commit are protected with it doing
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- * actual [de]allocation without holding any lock. However, given
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- * what this allocator does, I think it's better to let them run
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- * sequentially.
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+ * Synchronization rules.
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+ *
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+ * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former
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+ * protects allocation/reclaim paths, chunks and chunk->page arrays.
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+ * The latter is a spinlock and protects the index data structures -
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+ * chunk slots, rbtree, chunks and area maps in chunks.
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+ *
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+ * During allocation, pcpu_alloc_mutex is kept locked all the time and
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+ * pcpu_lock is grabbed and released as necessary. All actual memory
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+ * allocations are done using GFP_KERNEL with pcpu_lock released.
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+ *
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+ * Free path accesses and alters only the index data structures, so it
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+ * can be safely called from atomic context. When memory needs to be
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+ * returned to the system, free path schedules reclaim_work which
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+ * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be
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+ * reclaimed, release both locks and frees the chunks. Note that it's
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+ * necessary to grab both locks to remove a chunk from circulation as
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+ * allocation path might be referencing the chunk with only
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+ * pcpu_alloc_mutex locked.
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*/
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-static DEFINE_MUTEX(pcpu_mutex);
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+static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */
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+static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */
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static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */
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static struct rb_root pcpu_addr_root = RB_ROOT; /* chunks by address */
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+/* reclaim work to release fully free chunks, scheduled from free path */
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+static void pcpu_reclaim(struct work_struct *work);
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+static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim);
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+
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static int __pcpu_size_to_slot(int size)
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{
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int highbit = fls(size); /* size is in bytes */
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@@ -161,39 +178,44 @@ static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk,
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}
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/**
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- * pcpu_realloc - versatile realloc
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- * @p: the current pointer (can be NULL for new allocations)
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- * @size: the current size in bytes (can be 0 for new allocations)
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- * @new_size: the wanted new size in bytes (can be 0 for free)
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+ * pcpu_mem_alloc - allocate memory
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+ * @size: bytes to allocate
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+ *
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+ * Allocate @size bytes. If @size is smaller than PAGE_SIZE,
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+ * kzalloc() is used; otherwise, vmalloc() is used. The returned
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+ * memory is always zeroed.
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*
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- * More robust realloc which can be used to allocate, resize or free a
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- * memory area of arbitrary size. If the needed size goes over
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- * PAGE_SIZE, kernel VM is used.
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+ * CONTEXT:
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+ * Does GFP_KERNEL allocation.
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*
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* RETURNS:
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- * The new pointer on success, NULL on failure.
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+ * Pointer to the allocated area on success, NULL on failure.
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*/
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-static void *pcpu_realloc(void *p, size_t size, size_t new_size)
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+static void *pcpu_mem_alloc(size_t size)
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{
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- void *new;
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-
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- if (new_size <= PAGE_SIZE)
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- new = kmalloc(new_size, GFP_KERNEL);
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- else
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- new = vmalloc(new_size);
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- if (new_size && !new)
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- return NULL;
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-
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- memcpy(new, p, min(size, new_size));
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- if (new_size > size)
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- memset(new + size, 0, new_size - size);
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+ if (size <= PAGE_SIZE)
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+ return kzalloc(size, GFP_KERNEL);
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+ else {
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+ void *ptr = vmalloc(size);
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+ if (ptr)
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+ memset(ptr, 0, size);
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+ return ptr;
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+ }
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+}
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+/**
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+ * pcpu_mem_free - free memory
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+ * @ptr: memory to free
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+ * @size: size of the area
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+ *
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+ * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc().
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+ */
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+static void pcpu_mem_free(void *ptr, size_t size)
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+{
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if (size <= PAGE_SIZE)
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- kfree(p);
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+ kfree(ptr);
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else
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- vfree(p);
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-
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- return new;
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+ vfree(ptr);
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}
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/**
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@@ -203,13 +225,17 @@ static void *pcpu_realloc(void *p, size_t size, size_t new_size)
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*
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* This function is called after an allocation or free changed @chunk.
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* New slot according to the changed state is determined and @chunk is
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- * moved to the slot.
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+ * moved to the slot. Note that the reserved chunk is never put on
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+ * chunk slots.
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+ *
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+ * CONTEXT:
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+ * pcpu_lock.
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*/
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static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot)
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{
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int nslot = pcpu_chunk_slot(chunk);
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- if (oslot != nslot) {
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+ if (chunk != pcpu_reserved_chunk && oslot != nslot) {
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if (oslot < nslot)
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list_move(&chunk->list, &pcpu_slot[nslot]);
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else
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@@ -249,6 +275,9 @@ static struct rb_node **pcpu_chunk_rb_search(void *addr,
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* searchs for the chunk with the highest start address which isn't
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* beyond @addr.
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*
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+ * CONTEXT:
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+ * pcpu_lock.
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+ *
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* RETURNS:
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* The address of the found chunk.
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*/
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@@ -257,6 +286,15 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
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struct rb_node *n, *parent;
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struct pcpu_chunk *chunk;
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+ /* is it in the reserved chunk? */
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+ if (pcpu_reserved_chunk) {
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+ void *start = pcpu_reserved_chunk->vm->addr;
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+
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+ if (addr >= start && addr < start + pcpu_reserved_chunk_limit)
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+ return pcpu_reserved_chunk;
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+ }
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+
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+ /* nah... search the regular ones */
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n = *pcpu_chunk_rb_search(addr, &parent);
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if (!n) {
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/* no exactly matching chunk, the parent is the closest */
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@@ -280,6 +318,9 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
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* @new: chunk to insert
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*
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* Insert @new into address rb tree.
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+ *
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+ * CONTEXT:
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+ * pcpu_lock.
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*/
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static void pcpu_chunk_addr_insert(struct pcpu_chunk *new)
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{
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@@ -291,6 +332,66 @@ static void pcpu_chunk_addr_insert(struct pcpu_chunk *new)
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rb_insert_color(&new->rb_node, &pcpu_addr_root);
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}
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+/**
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+ * pcpu_extend_area_map - extend area map for allocation
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+ * @chunk: target chunk
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+ *
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+ * Extend area map of @chunk so that it can accomodate an allocation.
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+ * A single allocation can split an area into three areas, so this
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+ * function makes sure that @chunk->map has at least two extra slots.
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+ *
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+ * CONTEXT:
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+ * pcpu_alloc_mutex, pcpu_lock. pcpu_lock is released and reacquired
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+ * if area map is extended.
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+ *
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+ * RETURNS:
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+ * 0 if noop, 1 if successfully extended, -errno on failure.
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+ */
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+static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
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+{
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+ int new_alloc;
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+ int *new;
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+ size_t size;
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+
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+ /* has enough? */
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+ if (chunk->map_alloc >= chunk->map_used + 2)
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+ return 0;
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+
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+ spin_unlock_irq(&pcpu_lock);
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+
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+ new_alloc = PCPU_DFL_MAP_ALLOC;
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+ while (new_alloc < chunk->map_used + 2)
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+ new_alloc *= 2;
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+
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+ new = pcpu_mem_alloc(new_alloc * sizeof(new[0]));
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+ if (!new) {
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+ spin_lock_irq(&pcpu_lock);
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+ return -ENOMEM;
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+ }
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+
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+ /*
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+ * Acquire pcpu_lock and switch to new area map. Only free
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+ * could have happened inbetween, so map_used couldn't have
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+ * grown.
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+ */
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+ spin_lock_irq(&pcpu_lock);
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+ BUG_ON(new_alloc < chunk->map_used + 2);
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+
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+ size = chunk->map_alloc * sizeof(chunk->map[0]);
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+ memcpy(new, chunk->map, size);
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+
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+ /*
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+ * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is
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+ * one of the first chunks and still using static map.
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+ */
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+ if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC)
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+ pcpu_mem_free(chunk->map, size);
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+
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+ chunk->map_alloc = new_alloc;
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+ chunk->map = new;
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+ return 0;
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+}
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+
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/**
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* pcpu_split_block - split a map block
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* @chunk: chunk of interest
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@@ -306,33 +407,19 @@ static void pcpu_chunk_addr_insert(struct pcpu_chunk *new)
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* depending on @head, is reduced by @tail bytes and @tail byte block
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* is inserted after the target block.
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*
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- * RETURNS:
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- * 0 on success, -errno on failure.
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+ * @chunk->map must have enough free slots to accomodate the split.
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+ *
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+ * CONTEXT:
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+ * pcpu_lock.
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*/
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-static int pcpu_split_block(struct pcpu_chunk *chunk, int i, int head, int tail)
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+static void pcpu_split_block(struct pcpu_chunk *chunk, int i,
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+ int head, int tail)
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{
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int nr_extra = !!head + !!tail;
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- int target = chunk->map_used + nr_extra;
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-
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- /* reallocation required? */
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- if (chunk->map_alloc < target) {
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- int new_alloc = chunk->map_alloc;
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- int *new;
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- while (new_alloc < target)
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- new_alloc *= 2;
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+ BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra);
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- new = pcpu_realloc(chunk->map,
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- chunk->map_alloc * sizeof(new[0]),
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- new_alloc * sizeof(new[0]));
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- if (!new)
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- return -ENOMEM;
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-
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- chunk->map_alloc = new_alloc;
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- chunk->map = new;
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- }
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-
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- /* insert a new subblock */
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+ /* insert new subblocks */
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memmove(&chunk->map[i + nr_extra], &chunk->map[i],
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sizeof(chunk->map[0]) * (chunk->map_used - i));
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chunk->map_used += nr_extra;
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@@ -345,7 +432,6 @@ static int pcpu_split_block(struct pcpu_chunk *chunk, int i, int head, int tail)
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chunk->map[i++] -= tail;
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chunk->map[i] = tail;
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}
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- return 0;
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}
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/**
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@@ -358,8 +444,14 @@ static int pcpu_split_block(struct pcpu_chunk *chunk, int i, int head, int tail)
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* Note that this function only allocates the offset. It doesn't
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* populate or map the area.
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*
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+ * @chunk->map must have at least two free slots.
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+ *
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+ * CONTEXT:
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+ * pcpu_lock.
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+ *
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* RETURNS:
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- * Allocated offset in @chunk on success, -errno on failure.
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+ * Allocated offset in @chunk on success, -1 if no matching area is
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+ * found.
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*/
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static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
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{
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@@ -367,22 +459,6 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
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int max_contig = 0;
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int i, off;
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- /*
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- * The static chunk initially doesn't have map attached
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- * because kmalloc wasn't available during init. Give it one.
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- */
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- if (unlikely(!chunk->map)) {
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- chunk->map = pcpu_realloc(NULL, 0,
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- PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
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- if (!chunk->map)
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- return -ENOMEM;
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-
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- chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
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- chunk->map[chunk->map_used++] = -pcpu_static_size;
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- if (chunk->free_size)
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- chunk->map[chunk->map_used++] = chunk->free_size;
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- }
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-
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for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) {
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bool is_last = i + 1 == chunk->map_used;
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int head, tail;
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@@ -423,8 +499,7 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
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/* split if warranted */
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if (head || tail) {
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- if (pcpu_split_block(chunk, i, head, tail))
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- return -ENOMEM;
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+ pcpu_split_block(chunk, i, head, tail);
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if (head) {
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i++;
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off += head;
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@@ -451,14 +526,8 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
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chunk->contig_hint = max_contig; /* fully scanned */
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pcpu_chunk_relocate(chunk, oslot);
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- /*
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- * Tell the upper layer that this chunk has no area left.
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- * Note that this is not an error condition but a notification
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- * to upper layer that it needs to look at other chunks.
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- * -ENOSPC is chosen as it isn't used in memory subsystem and
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- * matches the meaning in a way.
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- */
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- return -ENOSPC;
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+ /* tell the upper layer that this chunk has no matching area */
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+ return -1;
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}
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/**
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@@ -469,6 +538,9 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
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* Free area starting from @freeme to @chunk. Note that this function
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* only modifies the allocation map. It doesn't depopulate or unmap
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* the area.
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+ *
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+ * CONTEXT:
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+ * pcpu_lock.
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*/
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static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
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{
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@@ -554,6 +626,9 @@ static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end,
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* For each cpu, depopulate and unmap pages [@page_start,@page_end)
|
|
|
* from @chunk. If @flush is true, vcache is flushed before unmapping
|
|
|
* and tlb after.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * pcpu_alloc_mutex.
|
|
|
*/
|
|
|
static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size,
|
|
|
bool flush)
|
|
|
@@ -632,6 +707,9 @@ static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)
|
|
|
*
|
|
|
* For each cpu, populate and map pages [@page_start,@page_end) into
|
|
|
* @chunk. The area is cleared on return.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * pcpu_alloc_mutex, does GFP_KERNEL allocation.
|
|
|
*/
|
|
|
static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
|
|
|
{
|
|
|
@@ -686,7 +764,7 @@ static void free_pcpu_chunk(struct pcpu_chunk *chunk)
|
|
|
return;
|
|
|
if (chunk->vm)
|
|
|
free_vm_area(chunk->vm);
|
|
|
- pcpu_realloc(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]), 0);
|
|
|
+ pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
|
|
|
kfree(chunk);
|
|
|
}
|
|
|
|
|
|
@@ -698,10 +776,10 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
|
|
|
if (!chunk)
|
|
|
return NULL;
|
|
|
|
|
|
- chunk->map = pcpu_realloc(NULL, 0,
|
|
|
- PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
|
|
|
+ chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
|
|
|
chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
|
|
|
chunk->map[chunk->map_used++] = pcpu_unit_size;
|
|
|
+ chunk->page = chunk->page_ar;
|
|
|
|
|
|
chunk->vm = get_vm_area(pcpu_chunk_size, GFP_KERNEL);
|
|
|
if (!chunk->vm) {
|
|
|
@@ -717,19 +795,21 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
- * __alloc_percpu - allocate percpu area
|
|
|
+ * pcpu_alloc - the percpu allocator
|
|
|
* @size: size of area to allocate in bytes
|
|
|
* @align: alignment of area (max PAGE_SIZE)
|
|
|
+ * @reserved: allocate from the reserved chunk if available
|
|
|
*
|
|
|
- * Allocate percpu area of @size bytes aligned at @align. Might
|
|
|
- * sleep. Might trigger writeouts.
|
|
|
+ * Allocate percpu area of @size bytes aligned at @align.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * Does GFP_KERNEL allocation.
|
|
|
*
|
|
|
* RETURNS:
|
|
|
* Percpu pointer to the allocated area on success, NULL on failure.
|
|
|
*/
|
|
|
-void *__alloc_percpu(size_t size, size_t align)
|
|
|
+static void *pcpu_alloc(size_t size, size_t align, bool reserved)
|
|
|
{
|
|
|
- void *ptr = NULL;
|
|
|
struct pcpu_chunk *chunk;
|
|
|
int slot, off;
|
|
|
|
|
|
@@ -739,90 +819,192 @@ void *__alloc_percpu(size_t size, size_t align)
|
|
|
return NULL;
|
|
|
}
|
|
|
|
|
|
- mutex_lock(&pcpu_mutex);
|
|
|
+ mutex_lock(&pcpu_alloc_mutex);
|
|
|
+ spin_lock_irq(&pcpu_lock);
|
|
|
+
|
|
|
+ /* serve reserved allocations from the reserved chunk if available */
|
|
|
+ if (reserved && pcpu_reserved_chunk) {
|
|
|
+ chunk = pcpu_reserved_chunk;
|
|
|
+ if (size > chunk->contig_hint ||
|
|
|
+ pcpu_extend_area_map(chunk) < 0)
|
|
|
+ goto fail_unlock;
|
|
|
+ off = pcpu_alloc_area(chunk, size, align);
|
|
|
+ if (off >= 0)
|
|
|
+ goto area_found;
|
|
|
+ goto fail_unlock;
|
|
|
+ }
|
|
|
|
|
|
- /* allocate area */
|
|
|
+restart:
|
|
|
+ /* search through normal chunks */
|
|
|
for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) {
|
|
|
list_for_each_entry(chunk, &pcpu_slot[slot], list) {
|
|
|
if (size > chunk->contig_hint)
|
|
|
continue;
|
|
|
+
|
|
|
+ switch (pcpu_extend_area_map(chunk)) {
|
|
|
+ case 0:
|
|
|
+ break;
|
|
|
+ case 1:
|
|
|
+ goto restart; /* pcpu_lock dropped, restart */
|
|
|
+ default:
|
|
|
+ goto fail_unlock;
|
|
|
+ }
|
|
|
+
|
|
|
off = pcpu_alloc_area(chunk, size, align);
|
|
|
if (off >= 0)
|
|
|
goto area_found;
|
|
|
- if (off != -ENOSPC)
|
|
|
- goto out_unlock;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
/* hmmm... no space left, create a new chunk */
|
|
|
+ spin_unlock_irq(&pcpu_lock);
|
|
|
+
|
|
|
chunk = alloc_pcpu_chunk();
|
|
|
if (!chunk)
|
|
|
- goto out_unlock;
|
|
|
+ goto fail_unlock_mutex;
|
|
|
+
|
|
|
+ spin_lock_irq(&pcpu_lock);
|
|
|
pcpu_chunk_relocate(chunk, -1);
|
|
|
pcpu_chunk_addr_insert(chunk);
|
|
|
-
|
|
|
- off = pcpu_alloc_area(chunk, size, align);
|
|
|
- if (off < 0)
|
|
|
- goto out_unlock;
|
|
|
+ goto restart;
|
|
|
|
|
|
area_found:
|
|
|
+ spin_unlock_irq(&pcpu_lock);
|
|
|
+
|
|
|
/* populate, map and clear the area */
|
|
|
if (pcpu_populate_chunk(chunk, off, size)) {
|
|
|
+ spin_lock_irq(&pcpu_lock);
|
|
|
pcpu_free_area(chunk, off);
|
|
|
- goto out_unlock;
|
|
|
+ goto fail_unlock;
|
|
|
}
|
|
|
|
|
|
- ptr = __addr_to_pcpu_ptr(chunk->vm->addr + off);
|
|
|
-out_unlock:
|
|
|
- mutex_unlock(&pcpu_mutex);
|
|
|
- return ptr;
|
|
|
+ mutex_unlock(&pcpu_alloc_mutex);
|
|
|
+
|
|
|
+ return __addr_to_pcpu_ptr(chunk->vm->addr + off);
|
|
|
+
|
|
|
+fail_unlock:
|
|
|
+ spin_unlock_irq(&pcpu_lock);
|
|
|
+fail_unlock_mutex:
|
|
|
+ mutex_unlock(&pcpu_alloc_mutex);
|
|
|
+ return NULL;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * __alloc_percpu - allocate dynamic percpu area
|
|
|
+ * @size: size of area to allocate in bytes
|
|
|
+ * @align: alignment of area (max PAGE_SIZE)
|
|
|
+ *
|
|
|
+ * Allocate percpu area of @size bytes aligned at @align. Might
|
|
|
+ * sleep. Might trigger writeouts.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * Does GFP_KERNEL allocation.
|
|
|
+ *
|
|
|
+ * RETURNS:
|
|
|
+ * Percpu pointer to the allocated area on success, NULL on failure.
|
|
|
+ */
|
|
|
+void *__alloc_percpu(size_t size, size_t align)
|
|
|
+{
|
|
|
+ return pcpu_alloc(size, align, false);
|
|
|
}
|
|
|
EXPORT_SYMBOL_GPL(__alloc_percpu);
|
|
|
|
|
|
-static void pcpu_kill_chunk(struct pcpu_chunk *chunk)
|
|
|
+/**
|
|
|
+ * __alloc_reserved_percpu - allocate reserved percpu area
|
|
|
+ * @size: size of area to allocate in bytes
|
|
|
+ * @align: alignment of area (max PAGE_SIZE)
|
|
|
+ *
|
|
|
+ * Allocate percpu area of @size bytes aligned at @align from reserved
|
|
|
+ * percpu area if arch has set it up; otherwise, allocation is served
|
|
|
+ * from the same dynamic area. Might sleep. Might trigger writeouts.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * Does GFP_KERNEL allocation.
|
|
|
+ *
|
|
|
+ * RETURNS:
|
|
|
+ * Percpu pointer to the allocated area on success, NULL on failure.
|
|
|
+ */
|
|
|
+void *__alloc_reserved_percpu(size_t size, size_t align)
|
|
|
+{
|
|
|
+ return pcpu_alloc(size, align, true);
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * pcpu_reclaim - reclaim fully free chunks, workqueue function
|
|
|
+ * @work: unused
|
|
|
+ *
|
|
|
+ * Reclaim all fully free chunks except for the first one.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * workqueue context.
|
|
|
+ */
|
|
|
+static void pcpu_reclaim(struct work_struct *work)
|
|
|
{
|
|
|
- WARN_ON(chunk->immutable);
|
|
|
- pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false);
|
|
|
- list_del(&chunk->list);
|
|
|
- rb_erase(&chunk->rb_node, &pcpu_addr_root);
|
|
|
- free_pcpu_chunk(chunk);
|
|
|
+ LIST_HEAD(todo);
|
|
|
+ struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1];
|
|
|
+ struct pcpu_chunk *chunk, *next;
|
|
|
+
|
|
|
+ mutex_lock(&pcpu_alloc_mutex);
|
|
|
+ spin_lock_irq(&pcpu_lock);
|
|
|
+
|
|
|
+ list_for_each_entry_safe(chunk, next, head, list) {
|
|
|
+ WARN_ON(chunk->immutable);
|
|
|
+
|
|
|
+ /* spare the first one */
|
|
|
+ if (chunk == list_first_entry(head, struct pcpu_chunk, list))
|
|
|
+ continue;
|
|
|
+
|
|
|
+ rb_erase(&chunk->rb_node, &pcpu_addr_root);
|
|
|
+ list_move(&chunk->list, &todo);
|
|
|
+ }
|
|
|
+
|
|
|
+ spin_unlock_irq(&pcpu_lock);
|
|
|
+ mutex_unlock(&pcpu_alloc_mutex);
|
|
|
+
|
|
|
+ list_for_each_entry_safe(chunk, next, &todo, list) {
|
|
|
+ pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false);
|
|
|
+ free_pcpu_chunk(chunk);
|
|
|
+ }
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* free_percpu - free percpu area
|
|
|
* @ptr: pointer to area to free
|
|
|
*
|
|
|
- * Free percpu area @ptr. Might sleep.
|
|
|
+ * Free percpu area @ptr.
|
|
|
+ *
|
|
|
+ * CONTEXT:
|
|
|
+ * Can be called from atomic context.
|
|
|
*/
|
|
|
void free_percpu(void *ptr)
|
|
|
{
|
|
|
void *addr = __pcpu_ptr_to_addr(ptr);
|
|
|
struct pcpu_chunk *chunk;
|
|
|
+ unsigned long flags;
|
|
|
int off;
|
|
|
|
|
|
if (!ptr)
|
|
|
return;
|
|
|
|
|
|
- mutex_lock(&pcpu_mutex);
|
|
|
+ spin_lock_irqsave(&pcpu_lock, flags);
|
|
|
|
|
|
chunk = pcpu_chunk_addr_search(addr);
|
|
|
off = addr - chunk->vm->addr;
|
|
|
|
|
|
pcpu_free_area(chunk, off);
|
|
|
|
|
|
- /* the chunk became fully free, kill one if there are other free ones */
|
|
|
+ /* if there are more than one fully free chunks, wake up grim reaper */
|
|
|
if (chunk->free_size == pcpu_unit_size) {
|
|
|
struct pcpu_chunk *pos;
|
|
|
|
|
|
- list_for_each_entry(pos,
|
|
|
- &pcpu_slot[pcpu_chunk_slot(chunk)], list)
|
|
|
+ list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list)
|
|
|
if (pos != chunk) {
|
|
|
- pcpu_kill_chunk(pos);
|
|
|
+ schedule_work(&pcpu_reclaim_work);
|
|
|
break;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
- mutex_unlock(&pcpu_mutex);
|
|
|
+ spin_unlock_irqrestore(&pcpu_lock, flags);
|
|
|
}
|
|
|
EXPORT_SYMBOL_GPL(free_percpu);
|
|
|
|
|
|
@@ -830,8 +1012,9 @@ EXPORT_SYMBOL_GPL(free_percpu);
|
|
|
* pcpu_setup_first_chunk - initialize the first percpu chunk
|
|
|
* @get_page_fn: callback to fetch page pointer
|
|
|
* @static_size: the size of static percpu area in bytes
|
|
|
- * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, 0 for auto
|
|
|
- * @free_size: free size in bytes, 0 for auto
|
|
|
+ * @reserved_size: the size of reserved percpu area in bytes
|
|
|
+ * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto
|
|
|
+ * @dyn_size: free size for dynamic allocation in bytes, -1 for auto
|
|
|
* @base_addr: mapped address, NULL for auto
|
|
|
* @populate_pte_fn: callback to allocate pagetable, NULL if unnecessary
|
|
|
*
|
|
|
@@ -848,13 +1031,22 @@ EXPORT_SYMBOL_GPL(free_percpu);
|
|
|
* indicates end of pages for the cpu. Note that @get_page_fn() must
|
|
|
* return the same number of pages for all cpus.
|
|
|
*
|
|
|
- * @unit_size, if non-zero, determines unit size and must be aligned
|
|
|
- * to PAGE_SIZE and equal to or larger than @static_size + @free_size.
|
|
|
+ * @reserved_size, if non-zero, specifies the amount of bytes to
|
|
|
+ * reserve after the static area in the first chunk. This reserves
|
|
|
+ * the first chunk such that it's available only through reserved
|
|
|
+ * percpu allocation. This is primarily used to serve module percpu
|
|
|
+ * static areas on architectures where the addressing model has
|
|
|
+ * limited offset range for symbol relocations to guarantee module
|
|
|
+ * percpu symbols fall inside the relocatable range.
|
|
|
*
|
|
|
- * @free_size determines the number of free bytes after the static
|
|
|
- * area in the first chunk. If zero, whatever left is available.
|
|
|
- * Specifying non-zero value make percpu leave the area after
|
|
|
- * @static_size + @free_size alone.
|
|
|
+ * @unit_size, if non-negative, specifies unit size and must be
|
|
|
+ * aligned to PAGE_SIZE and equal to or larger than @static_size +
|
|
|
+ * @reserved_size + @dyn_size.
|
|
|
+ *
|
|
|
+ * @dyn_size, if non-negative, limits the number of bytes available
|
|
|
+ * for dynamic allocation in the first chunk. Specifying non-negative
|
|
|
+ * value make percpu leave alone the area beyond @static_size +
|
|
|
+ * @reserved_size + @dyn_size.
|
|
|
*
|
|
|
* Non-null @base_addr means that the caller already allocated virtual
|
|
|
* region for the first chunk and mapped it. percpu must not mess
|
|
|
@@ -864,41 +1056,58 @@ EXPORT_SYMBOL_GPL(free_percpu);
|
|
|
* @populate_pte_fn is used to populate the pagetable. NULL means the
|
|
|
* caller already populated the pagetable.
|
|
|
*
|
|
|
+ * If the first chunk ends up with both reserved and dynamic areas, it
|
|
|
+ * is served by two chunks - one to serve the core static and reserved
|
|
|
+ * areas and the other for the dynamic area. They share the same vm
|
|
|
+ * and page map but uses different area allocation map to stay away
|
|
|
+ * from each other. The latter chunk is circulated in the chunk slots
|
|
|
+ * and available for dynamic allocation like any other chunks.
|
|
|
+ *
|
|
|
* RETURNS:
|
|
|
* The determined pcpu_unit_size which can be used to initialize
|
|
|
* percpu access.
|
|
|
*/
|
|
|
size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
|
|
|
- size_t static_size, size_t unit_size,
|
|
|
- size_t free_size, void *base_addr,
|
|
|
+ size_t static_size, size_t reserved_size,
|
|
|
+ ssize_t unit_size, ssize_t dyn_size,
|
|
|
+ void *base_addr,
|
|
|
pcpu_populate_pte_fn_t populate_pte_fn)
|
|
|
{
|
|
|
- static struct vm_struct static_vm;
|
|
|
- struct pcpu_chunk *static_chunk;
|
|
|
+ static struct vm_struct first_vm;
|
|
|
+ static int smap[2], dmap[2];
|
|
|
+ struct pcpu_chunk *schunk, *dchunk = NULL;
|
|
|
unsigned int cpu;
|
|
|
int nr_pages;
|
|
|
int err, i;
|
|
|
|
|
|
/* santiy checks */
|
|
|
+ BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC ||
|
|
|
+ ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
|
|
|
BUG_ON(!static_size);
|
|
|
- BUG_ON(!unit_size && free_size);
|
|
|
- BUG_ON(unit_size && unit_size < static_size + free_size);
|
|
|
- BUG_ON(unit_size & ~PAGE_MASK);
|
|
|
- BUG_ON(base_addr && !unit_size);
|
|
|
+ if (unit_size >= 0) {
|
|
|
+ BUG_ON(unit_size < static_size + reserved_size +
|
|
|
+ (dyn_size >= 0 ? dyn_size : 0));
|
|
|
+ BUG_ON(unit_size & ~PAGE_MASK);
|
|
|
+ } else {
|
|
|
+ BUG_ON(dyn_size >= 0);
|
|
|
+ BUG_ON(base_addr);
|
|
|
+ }
|
|
|
BUG_ON(base_addr && populate_pte_fn);
|
|
|
|
|
|
- if (unit_size)
|
|
|
+ if (unit_size >= 0)
|
|
|
pcpu_unit_pages = unit_size >> PAGE_SHIFT;
|
|
|
else
|
|
|
pcpu_unit_pages = max_t(int, PCPU_MIN_UNIT_SIZE >> PAGE_SHIFT,
|
|
|
- PFN_UP(static_size));
|
|
|
+ PFN_UP(static_size + reserved_size));
|
|
|
|
|
|
- pcpu_static_size = static_size;
|
|
|
pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
|
|
|
pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size;
|
|
|
pcpu_chunk_struct_size = sizeof(struct pcpu_chunk)
|
|
|
+ num_possible_cpus() * pcpu_unit_pages * sizeof(struct page *);
|
|
|
|
|
|
+ if (dyn_size < 0)
|
|
|
+ dyn_size = pcpu_unit_size - static_size - reserved_size;
|
|
|
+
|
|
|
/*
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* Allocate chunk slots. The additional last slot is for
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* empty chunks.
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@@ -908,33 +1117,66 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
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for (i = 0; i < pcpu_nr_slots; i++)
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INIT_LIST_HEAD(&pcpu_slot[i]);
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- /* init static_chunk */
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- static_chunk = alloc_bootmem(pcpu_chunk_struct_size);
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- INIT_LIST_HEAD(&static_chunk->list);
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- static_chunk->vm = &static_vm;
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-
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- if (free_size)
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- static_chunk->free_size = free_size;
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- else
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- static_chunk->free_size = pcpu_unit_size - pcpu_static_size;
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-
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- static_chunk->contig_hint = static_chunk->free_size;
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+ /*
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+ * Initialize static chunk. If reserved_size is zero, the
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+ * static chunk covers static area + dynamic allocation area
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+ * in the first chunk. If reserved_size is not zero, it
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+ * covers static area + reserved area (mostly used for module
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+ * static percpu allocation).
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+ */
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+ schunk = alloc_bootmem(pcpu_chunk_struct_size);
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+ INIT_LIST_HEAD(&schunk->list);
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+ schunk->vm = &first_vm;
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+ schunk->map = smap;
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+ schunk->map_alloc = ARRAY_SIZE(smap);
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+ schunk->page = schunk->page_ar;
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+
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+ if (reserved_size) {
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+ schunk->free_size = reserved_size;
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+ pcpu_reserved_chunk = schunk; /* not for dynamic alloc */
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+ } else {
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+ schunk->free_size = dyn_size;
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+ dyn_size = 0; /* dynamic area covered */
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+ }
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+ schunk->contig_hint = schunk->free_size;
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+
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+ schunk->map[schunk->map_used++] = -static_size;
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+ if (schunk->free_size)
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+ schunk->map[schunk->map_used++] = schunk->free_size;
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+
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+ pcpu_reserved_chunk_limit = static_size + schunk->free_size;
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+
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+ /* init dynamic chunk if necessary */
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+ if (dyn_size) {
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+ dchunk = alloc_bootmem(sizeof(struct pcpu_chunk));
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+ INIT_LIST_HEAD(&dchunk->list);
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+ dchunk->vm = &first_vm;
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+ dchunk->map = dmap;
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+ dchunk->map_alloc = ARRAY_SIZE(dmap);
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+ dchunk->page = schunk->page_ar; /* share page map with schunk */
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+
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+ dchunk->contig_hint = dchunk->free_size = dyn_size;
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+ dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit;
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+ dchunk->map[dchunk->map_used++] = dchunk->free_size;
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+ }
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/* allocate vm address */
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- static_vm.flags = VM_ALLOC;
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- static_vm.size = pcpu_chunk_size;
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+ first_vm.flags = VM_ALLOC;
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+ first_vm.size = pcpu_chunk_size;
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if (!base_addr)
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- vm_area_register_early(&static_vm, PAGE_SIZE);
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+ vm_area_register_early(&first_vm, PAGE_SIZE);
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else {
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/*
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* Pages already mapped. No need to remap into
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- * vmalloc area. In this case the static chunk can't
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- * be mapped or unmapped by percpu and is marked
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+ * vmalloc area. In this case the first chunks can't
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+ * be mapped or unmapped by percpu and are marked
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* immutable.
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*/
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- static_vm.addr = base_addr;
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- static_chunk->immutable = true;
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+ first_vm.addr = base_addr;
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+ schunk->immutable = true;
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+ if (dchunk)
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+ dchunk->immutable = true;
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}
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/* assign pages */
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@@ -945,10 +1187,10 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
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if (!page)
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break;
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- *pcpu_chunk_pagep(static_chunk, cpu, i) = page;
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+ *pcpu_chunk_pagep(schunk, cpu, i) = page;
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}
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- BUG_ON(i < PFN_UP(pcpu_static_size));
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+ BUG_ON(i < PFN_UP(static_size));
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if (nr_pages < 0)
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nr_pages = i;
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@@ -960,20 +1202,25 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
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if (populate_pte_fn) {
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for_each_possible_cpu(cpu)
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for (i = 0; i < nr_pages; i++)
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- populate_pte_fn(pcpu_chunk_addr(static_chunk,
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+ populate_pte_fn(pcpu_chunk_addr(schunk,
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cpu, i));
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- err = pcpu_map(static_chunk, 0, nr_pages);
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+ err = pcpu_map(schunk, 0, nr_pages);
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if (err)
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panic("failed to setup static percpu area, err=%d\n",
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err);
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}
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- /* link static_chunk in */
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- pcpu_chunk_relocate(static_chunk, -1);
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- pcpu_chunk_addr_insert(static_chunk);
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+ /* link the first chunk in */
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+ if (!dchunk) {
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+ pcpu_chunk_relocate(schunk, -1);
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+ pcpu_chunk_addr_insert(schunk);
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+ } else {
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+ pcpu_chunk_relocate(dchunk, -1);
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+ pcpu_chunk_addr_insert(dchunk);
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+ }
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/* we're done */
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- pcpu_base_addr = (void *)pcpu_chunk_addr(static_chunk, 0, 0);
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+ pcpu_base_addr = (void *)pcpu_chunk_addr(schunk, 0, 0);
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return pcpu_unit_size;
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}
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Ingo Molnar