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![Tejun Heo](/assets/img/avatar_default.png)
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
388 lines
8.2 KiB
C
388 lines
8.2 KiB
C
/*
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* Infrastructure for statistic tracing (histogram output).
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*
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* Copyright (C) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
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*
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* Based on the code from trace_branch.c which is
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* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
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*
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*/
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/rbtree.h>
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#include <linux/debugfs.h>
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#include "trace_stat.h"
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#include "trace.h"
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/*
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* List of stat red-black nodes from a tracer
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* We use a such tree to sort quickly the stat
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* entries from the tracer.
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*/
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struct stat_node {
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struct rb_node node;
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void *stat;
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};
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/* A stat session is the stats output in one file */
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struct stat_session {
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struct list_head session_list;
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struct tracer_stat *ts;
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struct rb_root stat_root;
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struct mutex stat_mutex;
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struct dentry *file;
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};
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/* All of the sessions currently in use. Each stat file embed one session */
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static LIST_HEAD(all_stat_sessions);
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static DEFINE_MUTEX(all_stat_sessions_mutex);
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/* The root directory for all stat files */
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static struct dentry *stat_dir;
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/*
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* Iterate through the rbtree using a post order traversal path
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* to release the next node.
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* It won't necessary release one at each iteration
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* but it will at least advance closer to the next one
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* to be released.
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*/
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static struct rb_node *release_next(struct tracer_stat *ts,
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struct rb_node *node)
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{
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struct stat_node *snode;
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struct rb_node *parent = rb_parent(node);
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if (node->rb_left)
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return node->rb_left;
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else if (node->rb_right)
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return node->rb_right;
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else {
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if (!parent)
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;
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else if (parent->rb_left == node)
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parent->rb_left = NULL;
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else
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parent->rb_right = NULL;
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snode = container_of(node, struct stat_node, node);
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if (ts->stat_release)
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ts->stat_release(snode->stat);
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kfree(snode);
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return parent;
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}
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}
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static void __reset_stat_session(struct stat_session *session)
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{
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struct rb_node *node = session->stat_root.rb_node;
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while (node)
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node = release_next(session->ts, node);
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session->stat_root = RB_ROOT;
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}
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static void reset_stat_session(struct stat_session *session)
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{
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mutex_lock(&session->stat_mutex);
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__reset_stat_session(session);
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mutex_unlock(&session->stat_mutex);
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}
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static void destroy_session(struct stat_session *session)
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{
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debugfs_remove(session->file);
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__reset_stat_session(session);
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mutex_destroy(&session->stat_mutex);
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kfree(session);
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}
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typedef int (*cmp_stat_t)(void *, void *);
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static int insert_stat(struct rb_root *root, void *stat, cmp_stat_t cmp)
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{
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struct rb_node **new = &(root->rb_node), *parent = NULL;
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struct stat_node *data;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->stat = stat;
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/*
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* Figure out where to put new node
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* This is a descendent sorting
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*/
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while (*new) {
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struct stat_node *this;
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int result;
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this = container_of(*new, struct stat_node, node);
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result = cmp(data->stat, this->stat);
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parent = *new;
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if (result >= 0)
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new = &((*new)->rb_left);
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else
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new = &((*new)->rb_right);
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}
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rb_link_node(&data->node, parent, new);
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rb_insert_color(&data->node, root);
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return 0;
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}
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/*
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* For tracers that don't provide a stat_cmp callback.
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* This one will force an insertion as right-most node
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* in the rbtree.
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*/
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static int dummy_cmp(void *p1, void *p2)
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{
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return -1;
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}
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/*
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* Initialize the stat rbtree at each trace_stat file opening.
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* All of these copies and sorting are required on all opening
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* since the stats could have changed between two file sessions.
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*/
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static int stat_seq_init(struct stat_session *session)
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{
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struct tracer_stat *ts = session->ts;
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struct rb_root *root = &session->stat_root;
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void *stat;
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int ret = 0;
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int i;
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mutex_lock(&session->stat_mutex);
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__reset_stat_session(session);
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if (!ts->stat_cmp)
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ts->stat_cmp = dummy_cmp;
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stat = ts->stat_start(ts);
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if (!stat)
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goto exit;
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ret = insert_stat(root, stat, ts->stat_cmp);
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if (ret)
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goto exit;
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/*
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* Iterate over the tracer stat entries and store them in an rbtree.
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*/
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for (i = 1; ; i++) {
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stat = ts->stat_next(stat, i);
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/* End of insertion */
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if (!stat)
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break;
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ret = insert_stat(root, stat, ts->stat_cmp);
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if (ret)
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goto exit_free_rbtree;
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}
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exit:
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mutex_unlock(&session->stat_mutex);
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return ret;
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exit_free_rbtree:
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__reset_stat_session(session);
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mutex_unlock(&session->stat_mutex);
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return ret;
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}
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static void *stat_seq_start(struct seq_file *s, loff_t *pos)
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{
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struct stat_session *session = s->private;
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struct rb_node *node;
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int n = *pos;
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int i;
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/* Prevent from tracer switch or rbtree modification */
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mutex_lock(&session->stat_mutex);
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/* If we are in the beginning of the file, print the headers */
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if (session->ts->stat_headers) {
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if (n == 0)
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return SEQ_START_TOKEN;
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n--;
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}
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node = rb_first(&session->stat_root);
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for (i = 0; node && i < n; i++)
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node = rb_next(node);
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return node;
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}
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static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos)
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{
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struct stat_session *session = s->private;
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struct rb_node *node = p;
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(*pos)++;
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if (p == SEQ_START_TOKEN)
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return rb_first(&session->stat_root);
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return rb_next(node);
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}
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static void stat_seq_stop(struct seq_file *s, void *p)
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{
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struct stat_session *session = s->private;
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mutex_unlock(&session->stat_mutex);
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}
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static int stat_seq_show(struct seq_file *s, void *v)
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{
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struct stat_session *session = s->private;
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struct stat_node *l = container_of(v, struct stat_node, node);
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if (v == SEQ_START_TOKEN)
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return session->ts->stat_headers(s);
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return session->ts->stat_show(s, l->stat);
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}
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static const struct seq_operations trace_stat_seq_ops = {
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.start = stat_seq_start,
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.next = stat_seq_next,
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.stop = stat_seq_stop,
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.show = stat_seq_show
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};
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/* The session stat is refilled and resorted at each stat file opening */
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static int tracing_stat_open(struct inode *inode, struct file *file)
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{
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int ret;
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struct seq_file *m;
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struct stat_session *session = inode->i_private;
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ret = stat_seq_init(session);
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if (ret)
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return ret;
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ret = seq_open(file, &trace_stat_seq_ops);
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if (ret) {
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reset_stat_session(session);
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return ret;
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}
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m = file->private_data;
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m->private = session;
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return ret;
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}
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/*
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* Avoid consuming memory with our now useless rbtree.
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*/
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static int tracing_stat_release(struct inode *i, struct file *f)
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{
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struct stat_session *session = i->i_private;
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reset_stat_session(session);
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return seq_release(i, f);
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}
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static const struct file_operations tracing_stat_fops = {
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.open = tracing_stat_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = tracing_stat_release
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};
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static int tracing_stat_init(void)
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{
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struct dentry *d_tracing;
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d_tracing = tracing_init_dentry();
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stat_dir = debugfs_create_dir("trace_stat", d_tracing);
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if (!stat_dir)
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pr_warning("Could not create debugfs "
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"'trace_stat' entry\n");
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return 0;
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}
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static int init_stat_file(struct stat_session *session)
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{
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if (!stat_dir && tracing_stat_init())
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return -ENODEV;
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session->file = debugfs_create_file(session->ts->name, 0644,
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stat_dir,
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session, &tracing_stat_fops);
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if (!session->file)
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return -ENOMEM;
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return 0;
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}
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int register_stat_tracer(struct tracer_stat *trace)
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{
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struct stat_session *session, *node;
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int ret;
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if (!trace)
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return -EINVAL;
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if (!trace->stat_start || !trace->stat_next || !trace->stat_show)
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return -EINVAL;
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/* Already registered? */
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mutex_lock(&all_stat_sessions_mutex);
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list_for_each_entry(node, &all_stat_sessions, session_list) {
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if (node->ts == trace) {
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mutex_unlock(&all_stat_sessions_mutex);
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return -EINVAL;
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}
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}
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mutex_unlock(&all_stat_sessions_mutex);
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/* Init the session */
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session = kzalloc(sizeof(*session), GFP_KERNEL);
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if (!session)
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return -ENOMEM;
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session->ts = trace;
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INIT_LIST_HEAD(&session->session_list);
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mutex_init(&session->stat_mutex);
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ret = init_stat_file(session);
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if (ret) {
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destroy_session(session);
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return ret;
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}
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/* Register */
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mutex_lock(&all_stat_sessions_mutex);
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list_add_tail(&session->session_list, &all_stat_sessions);
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mutex_unlock(&all_stat_sessions_mutex);
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return 0;
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}
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void unregister_stat_tracer(struct tracer_stat *trace)
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{
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struct stat_session *node, *tmp;
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mutex_lock(&all_stat_sessions_mutex);
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list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) {
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if (node->ts == trace) {
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list_del(&node->session_list);
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destroy_session(node);
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break;
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}
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}
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mutex_unlock(&all_stat_sessions_mutex);
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}
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