Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

 * Fix include order for bison/flex-generated C files, from Ben Hutchings

 * Build fixes and documentation corrections from David Ahern

 * Group parsing support, from Jiri Olsa

 * UI/gtk refactorings and improvements from Namhyung Kim

 * NULL deref fix for perf script, from Namhyung Kim

 * Assorted cleanups from Robert Richter

 * Let O= makes handle relative paths, from Steven Rostedt

 * perf script python fixes, from Feng Tang.

 * Improve 'perf lock' error message when the needed tracepoints
   are not present, from David Ahern.

 * Initial bash completion support, from Frederic Weisbecker

 * Allow building without libelf, from Namhyung Kim.

 * Support DWARF CFI based unwind to have callchains when %bp
   based unwinding is not possible, from Jiri Olsa.

 * Symbol resolution fixes, while fixing support PPC64 files with an .opt ELF
   section was the end goal, several fixes for code that handles all
   architectures and cleanups are included, from Cody Schafer.

 * Add a description for the JIT interface, from Andi Kleen.

 * Assorted fixes for Documentation and build in 32 bit, from Robert Richter

 * Add support for non-tracepoint events in perf script python, from Feng Tang

 * Cache the libtraceevent event_format associated to each evsel early, so that we
   avoid relookups, i.e. calling pevent_find_event repeatedly when processing
   tracepoint events.

   [ This is to reduce the surface contact with libtraceevents and make clear what
     is that the perf tools needs from that lib: so far parsing the common and per
     event fields. ]

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 90 insertions, 49 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e7dee617358e..f3b44a65fc7a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -31,27 +31,6 @@ EXPORT_SYMBOL_GPL(blkcg_root);
 
 static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
 
-struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup)
-{
-        return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),
-                            struct blkcg, css);
-}
-EXPORT_SYMBOL_GPL(cgroup_to_blkcg);
-
-static struct blkcg *task_blkcg(struct task_struct *tsk)
-{
-        return container_of(task_subsys_state(tsk, blkio_subsys_id),
-                            struct blkcg, css);
-}
-
-struct blkcg *bio_blkcg(struct bio *bio)
-{
-        if (bio && bio->bi_css)
-                return container_of(bio->bi_css, struct blkcg, css);
-        return task_blkcg(current);
-}
-EXPORT_SYMBOL_GPL(bio_blkcg);
-
 static bool blkcg_policy_enabled(struct request_queue *q,
                                  const struct blkcg_policy *pol)
 {
@@ -84,6 +63,7 @@ static void blkg_free(struct blkcg_gq *blkg)
                 kfree(pd);
         }
 
+        blk_exit_rl(&blkg->rl);
         kfree(blkg);
 }
 
@@ -91,16 +71,18 @@ static void blkg_free(struct blkcg_gq *blkg)
  * blkg_alloc - allocate a blkg
  * @blkcg: block cgroup the new blkg is associated with
  * @q: request_queue the new blkg is associated with
+ * @gfp_mask: allocation mask to use
  *
  * Allocate a new blkg assocating @blkcg and @q.
  */
-static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q)
+static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
+                                   gfp_t gfp_mask)
 {
         struct blkcg_gq *blkg;
         int i;
 
         /* alloc and init base part */
-        blkg = kzalloc_node(sizeof(*blkg), GFP_ATOMIC, q->node);
+        blkg = kzalloc_node(sizeof(*blkg), gfp_mask, q->node);
         if (!blkg)
                 return NULL;
 
@@ -109,6 +91,13 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q)
         blkg->blkcg = blkcg;
         blkg->refcnt = 1;
 
+        /* root blkg uses @q->root_rl, init rl only for !root blkgs */
+        if (blkcg != &blkcg_root) {
+                if (blk_init_rl(&blkg->rl, q, gfp_mask))
+                        goto err_free;
+                blkg->rl.blkg = blkg;
+        }
+
         for (i = 0; i < BLKCG_MAX_POLS; i++) {
                 struct blkcg_policy *pol = blkcg_policy[i];
                 struct blkg_policy_data *pd;
@@ -117,11 +106,9 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q)
                         continue;
 
                 /* alloc per-policy data and attach it to blkg */
-                pd = kzalloc_node(pol->pd_size, GFP_ATOMIC, q->node);
-                if (!pd) {
-                        blkg_free(blkg);
-                        return NULL;
-                }
+                pd = kzalloc_node(pol->pd_size, gfp_mask, q->node);
+                if (!pd)
+                        goto err_free;
 
                 blkg->pd[i] = pd;
                 pd->blkg = blkg;
@@ -132,6 +119,10 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q)
         }
 
         return blkg;
+
+err_free:
+        blkg_free(blkg);
+        return NULL;
 }
 
 static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
@@ -175,9 +166,13 @@ struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blkg_lookup);
 
+/*
+ * If @new_blkg is %NULL, this function tries to allocate a new one as
+ * necessary using %GFP_ATOMIC.  @new_blkg is always consumed on return.
+ */
 static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
-                                             struct request_queue *q)
-        __releases(q->queue_lock) __acquires(q->queue_lock)
+                                             struct request_queue *q,
+                                             struct blkcg_gq *new_blkg)
 {
         struct blkcg_gq *blkg;
         int ret;
@@ -189,24 +184,26 @@ static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
         blkg = __blkg_lookup(blkcg, q);
         if (blkg) {
                 rcu_assign_pointer(blkcg->blkg_hint, blkg);
-                return blkg;
+                goto out_free;
         }
 
         /* blkg holds a reference to blkcg */
-        if (!css_tryget(&blkcg->css))
-                return ERR_PTR(-EINVAL);
+        if (!css_tryget(&blkcg->css)) {
+                blkg = ERR_PTR(-EINVAL);
+                goto out_free;
+        }
 
         /* allocate */
-        ret = -ENOMEM;
-        blkg = blkg_alloc(blkcg, q);
-        if (unlikely(!blkg))
-                goto err_put;
+        if (!new_blkg) {
+                new_blkg = blkg_alloc(blkcg, q, GFP_ATOMIC);
+                if (unlikely(!new_blkg)) {
+                        blkg = ERR_PTR(-ENOMEM);
+                        goto out_put;
+                }
+        }
+        blkg = new_blkg;
 
         /* insert */
-        ret = radix_tree_preload(GFP_ATOMIC);
-        if (ret)
-                goto err_free;
-
         spin_lock(&blkcg->lock);
         ret = radix_tree_insert(&blkcg->blkg_tree, q->id, blkg);
         if (likely(!ret)) {
@@ -215,15 +212,15 @@ static struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg,
         }
         spin_unlock(&blkcg->lock);
 
-        radix_tree_preload_end();
-
         if (!ret)
                 return blkg;
-err_free:
-        blkg_free(blkg);
-err_put:
+
+        blkg = ERR_PTR(ret);
+out_put:
         css_put(&blkcg->css);
-        return ERR_PTR(ret);
+out_free:
+        blkg_free(new_blkg);
+        return blkg;
 }
 
 struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
@@ -235,7 +232,7 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
          */
         if (unlikely(blk_queue_bypass(q)))
                 return ERR_PTR(blk_queue_dead(q) ? -EINVAL : -EBUSY);
-        return __blkg_lookup_create(blkcg, q);
+        return __blkg_lookup_create(blkcg, q, NULL);
 }
 EXPORT_SYMBOL_GPL(blkg_lookup_create);
 
@@ -313,6 +310,38 @@ void __blkg_release(struct blkcg_gq *blkg)
 }
 EXPORT_SYMBOL_GPL(__blkg_release);
 
+/*
+ * The next function used by blk_queue_for_each_rl().  It's a bit tricky
+ * because the root blkg uses @q->root_rl instead of its own rl.
+ */
+struct request_list *__blk_queue_next_rl(struct request_list *rl,
+                                         struct request_queue *q)
+{
+        struct list_head *ent;
+        struct blkcg_gq *blkg;
+
+        /*
+         * Determine the current blkg list_head.  The first entry is
+         * root_rl which is off @q->blkg_list and mapped to the head.
+         */
+        if (rl == &q->root_rl) {
+                ent = &q->blkg_list;
+        } else {
+                blkg = container_of(rl, struct blkcg_gq, rl);
+                ent = &blkg->q_node;
+        }
+
+        /* walk to the next list_head, skip root blkcg */
+        ent = ent->next;
+        if (ent == &q->root_blkg->q_node)
+                ent = ent->next;
+        if (ent == &q->blkg_list)
+                return NULL;
+
+        blkg = container_of(ent, struct blkcg_gq, q_node);
+        return &blkg->rl;
+}
+
 static int blkcg_reset_stats(struct cgroup *cgroup, struct cftype *cftype,
                              u64 val)
 {
@@ -734,24 +763,36 @@ int blkcg_activate_policy(struct request_queue *q,
         struct blkcg_gq *blkg;
         struct blkg_policy_data *pd, *n;
         int cnt = 0, ret;
+        bool preloaded;
 
         if (blkcg_policy_enabled(q, pol))
                 return 0;
 
+        /* preallocations for root blkg */
+        blkg = blkg_alloc(&blkcg_root, q, GFP_KERNEL);
+        if (!blkg)
+                return -ENOMEM;
+
+        preloaded = !radix_tree_preload(GFP_KERNEL);
+
         blk_queue_bypass_start(q);
 
         /* make sure the root blkg exists and count the existing blkgs */
         spin_lock_irq(q->queue_lock);
 
         rcu_read_lock();
-        blkg = __blkg_lookup_create(&blkcg_root, q);
+        blkg = __blkg_lookup_create(&blkcg_root, q, blkg);
         rcu_read_unlock();
 
+        if (preloaded)
+                radix_tree_preload_end();
+
         if (IS_ERR(blkg)) {
                 ret = PTR_ERR(blkg);
                 goto out_unlock;
         }
         q->root_blkg = blkg;
+        q->root_rl.blkg = blkg;
 
         list_for_each_entry(blkg, &q->blkg_list, q_node)
                 cnt++;