166 lines
4.3 KiB
Diff
166 lines
4.3 KiB
Diff
From: Mike Galbraith <umgwanakikbuti@gmail.com>
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Date: Tue, 22 Mar 2016 11:16:09 +0100
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Subject: [PATCH] mm/zsmalloc: Use get/put_cpu_light in
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zs_map_object()/zs_unmap_object()
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.8/older/patches-4.8.2-rt2.tar.xz
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Otherwise, we get a ___might_sleep() splat.
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Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
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[bigeasy: replace the bitspin_lock() with a mutex]
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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mm/zsmalloc.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++----
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1 file changed, 69 insertions(+), 4 deletions(-)
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--- a/mm/zsmalloc.c
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+++ b/mm/zsmalloc.c
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@@ -71,7 +71,19 @@
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#define ZS_MAX_ZSPAGE_ORDER 2
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#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER)
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+
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+struct zsmalloc_handle {
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+ unsigned long addr;
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+ struct mutex lock;
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+};
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+
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+#define ZS_HANDLE_SIZE (sizeof(struct zsmalloc_handle))
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+
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+#else
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+
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#define ZS_HANDLE_SIZE (sizeof(unsigned long))
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+#endif
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/*
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* Object location (<PFN>, <obj_idx>) is encoded as
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@@ -351,9 +363,26 @@ static void destroy_cache(struct zs_pool
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static unsigned long cache_alloc_handle(struct zs_pool *pool, gfp_t gfp)
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{
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- return (unsigned long)kmem_cache_alloc(pool->handle_cachep,
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- gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE));
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+ void *p;
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+
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+ p = kmem_cache_alloc(pool->handle_cachep,
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+ gfp & ~(__GFP_HIGHMEM|__GFP_MOVABLE));
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ if (p) {
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+ struct zsmalloc_handle *zh = p;
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+
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+ mutex_init(&zh->lock);
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+ }
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+#endif
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+ return (unsigned long)p;
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+}
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+
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+static struct zsmalloc_handle *zs_get_pure_handle(unsigned long handle)
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+{
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+ return (void *)(handle &~((1 << OBJ_TAG_BITS) - 1));
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}
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+#endif
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static void cache_free_handle(struct zs_pool *pool, unsigned long handle)
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{
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@@ -373,12 +402,18 @@ static void cache_free_zspage(struct zs_
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static void record_obj(unsigned long handle, unsigned long obj)
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{
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
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+
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+ WRITE_ONCE(zh->addr, obj);
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+#else
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/*
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* lsb of @obj represents handle lock while other bits
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* represent object value the handle is pointing so
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* updating shouldn't do store tearing.
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*/
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WRITE_ONCE(*(unsigned long *)handle, obj);
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+#endif
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}
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/* zpool driver */
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@@ -902,7 +937,13 @@ static unsigned long location_to_obj(str
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static unsigned long handle_to_obj(unsigned long handle)
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{
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
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+
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+ return zh->addr;
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+#else
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return *(unsigned long *)handle;
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+#endif
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}
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static unsigned long obj_to_head(struct page *page, void *obj)
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@@ -916,22 +957,46 @@ static unsigned long obj_to_head(struct
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static inline int testpin_tag(unsigned long handle)
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{
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
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+
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+ return mutex_is_locked(&zh->lock);
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+#else
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return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle);
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+#endif
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}
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static inline int trypin_tag(unsigned long handle)
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{
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
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+
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+ return mutex_trylock(&zh->lock);
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+#else
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return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle);
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+#endif
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}
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static void pin_tag(unsigned long handle)
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{
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
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+
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+ return mutex_lock(&zh->lock);
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+#else
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bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle);
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+#endif
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}
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static void unpin_tag(unsigned long handle)
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{
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+#ifdef CONFIG_PREEMPT_RT_BASE
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+ struct zsmalloc_handle *zh = zs_get_pure_handle(handle);
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+
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+ return mutex_unlock(&zh->lock);
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+#else
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bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle);
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+#endif
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}
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static void reset_page(struct page *page)
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@@ -1423,7 +1488,7 @@ void *zs_map_object(struct zs_pool *pool
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class = pool->size_class[class_idx];
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off = (class->size * obj_idx) & ~PAGE_MASK;
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- area = &get_cpu_var(zs_map_area);
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+ area = per_cpu_ptr(&zs_map_area, get_cpu_light());
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area->vm_mm = mm;
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if (off + class->size <= PAGE_SIZE) {
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/* this object is contained entirely within a page */
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@@ -1477,7 +1542,7 @@ void zs_unmap_object(struct zs_pool *poo
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__zs_unmap_object(area, pages, off, class->size);
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}
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- put_cpu_var(zs_map_area);
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+ put_cpu_light();
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migrate_read_unlock(zspage);
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unpin_tag(handle);
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