c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2024-12-27 11:29:36 +03:00
Code Issues Packages Projects Releases Wiki Activity
b520b14305
mirror_zfs/module/splat/splat-internal.h
Brian Behlendorf e811949a57 Reimplement rwlocks for Linux lock profiling/analysis. 
It turns out that the previous rwlock implementation worked well but
did not integrate properly with the upstream kernel lock profiling/
analysis tools.  This is a major problem since it would be awfully
nice to be able to use the automatic lock checker and profiler.

The problem is that the upstream lock tools use the pre-processor
to create a lock class for each uniquely named locked.  Since the
rwsem was embedded in a wrapper structure the name was always the
same.  The effect was that we only ended up with one lock class for
the entire SPL which caused the lock dependency checker to flag
nearly everything as a possible deadlock.

The solution was to directly map a krwlock to a Linux rwsem using
a typedef there by eliminating the wrapper structure.  This was not
done initially because the rwsem implementation is specific to the arch.
To fully implement the Solaris krwlock API using only the provided rwsem
API is not possible.  It can only be done by directly accessing some of
the internal data member of the rwsem structure.

For example, the Linux API provides a different function for dropping
a reader vs writer lock.  Whereas the Solaris API uses the same function
and the caller does not pass in what type of lock it is.  This means to
properly drop the lock we need to determine if the lock is currently a
reader or writer lock.  Then we need to call the proper Linux API function.
Unfortunately, there is no provided API for this so we must extracted this
information directly from arch specific lock implementation.  This is
all do able, and what I did, but it does complicate things considerably.

The good news is that in addition to the profiling benefits of this
change.  We may see performance improvements due to slightly reduced
overhead when creating rwlocks and manipulating them.

The only function I was forced to sacrafice was rw_owner() because this
information is simply not stored anywhere in the rwsem.  Luckily this
appears not to be a commonly used function on Solaris, and it is my
understanding it is mainly used for debugging anyway.

In addition to the core rwlock changes, extensive updates were made to
the rwlock regression tests.  Each class of test was extended to provide
more API coverage and to be more rigerous in checking for misbehavior.

This is a pretty significant change and with that in mind I have been
careful to validate it on several platforms before committing.  The full
SPLAT regression test suite was run numberous times on all of the following
platforms.  This includes various kernels ranging from 2.6.16 to 2.6.29.

- SLES10   (ppc64)
- SLES11   (x86_64)
- CHAOS4.2 (x86_64)
- RHEL5.3  (x86_64)
- RHEL6    (x86_64)
- FC11     (x86_64)
2009-09-18 16:09:47 -07:00

254 lines
9.2 KiB
C
Raw Blame History

/*
* This file is part of the SPL: Solaris Porting Layer.
*
* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <behlendorf1@llnl.gov>,
* Herb Wartens <wartens2@llnl.gov>,
* Jim Garlick <garlick@llnl.gov>
* UCRL-CODE-235197
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _SPLAT_INTERNAL_H
#define _SPLAT_INTERNAL_H
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/elf.h>
#include <linux/limits.h>
#include <linux/version.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/swap.h>
#include <linux/delay.h>
#include <asm/ioctls.h>
#include <asm/uaccess.h>
#include <stdarg.h>
#include <sys/callb.h>
#include <sys/condvar.h>
#include <sys/cred.h>
#include <sys/sysmacros.h>
#include <sys/kmem.h>
#include <sys/kstat.h>
#include <sys/mutex.h>
#include <sys/random.h>
#include <sys/rwlock.h>
#include <sys/taskq.h>
#include <sys/thread.h>
#include <sys/time.h>
#include <sys/timer.h>
#include <sys/types.h>
#include <sys/kobj.h>
#include <sys/atomic.h>
#include <sys/list.h>
#include <sys/sunddi.h>
#include <linux/cdev.h>
#include "spl-device.h"
#include "splat-ctl.h"
#define SPLAT_SUBSYSTEM_INIT(type) \
({ splat_subsystem_t *_sub_; \
\
_sub_ = (splat_subsystem_t *)splat_##type##_init(); \
if (_sub_ == NULL) { \
printk(KERN_ERR "splat: Error initializing: " #type "\n"); \
} else { \
spin_lock(&splat_module_lock); \
list_add_tail(&(_sub_->subsystem_list), \
&splat_module_list); \
spin_unlock(&splat_module_lock); \
} \
})
#define SPLAT_SUBSYSTEM_FINI(type) \
({ splat_subsystem_t *_sub_, *_tmp_; \
int _id_, _flag_ = 0; \
\
_id_ = splat_##type##_id(); \
spin_lock(&splat_module_lock); \
list_for_each_entry_safe(_sub_, _tmp_, &splat_module_list, \
subsystem_list) { \
if (_sub_->desc.id == _id_) { \
list_del_init(&(_sub_->subsystem_list)); \
spin_unlock(&splat_module_lock); \
splat_##type##_fini(_sub_); \
spin_lock(&splat_module_lock); \
_flag_ = 1; \
} \
} \
spin_unlock(&splat_module_lock); \
\
if (!_flag_) \
printk(KERN_ERR "splat: Error finalizing: " #type "\n"); \
})
#define SPLAT_TEST_INIT(sub, n, d, tid, func) \
({ splat_test_t *_test_; \
\
_test_ = (splat_test_t *)kmalloc(sizeof(*_test_), GFP_KERNEL); \
if (_test_ == NULL) { \
printk(KERN_ERR "splat: Error initializing: " n "/" #tid" \n");\
} else { \
memset(_test_, 0, sizeof(*_test_)); \
strncpy(_test_->desc.name, n, SPLAT_NAME_SIZE-1); \
strncpy(_test_->desc.desc, d, SPLAT_DESC_SIZE-1); \
_test_->desc.id = tid; \
_test_->test = func; \
INIT_LIST_HEAD(&(_test_->test_list)); \
spin_lock(&((sub)->test_lock)); \
list_add_tail(&(_test_->test_list),&((sub)->test_list));\
spin_unlock(&((sub)->test_lock)); \
} \
})
#define SPLAT_TEST_FINI(sub, tid) \
({ splat_test_t *_test_, *_tmp_; \
int _flag_ = 0; \
\
spin_lock(&((sub)->test_lock)); \
list_for_each_entry_safe(_test_, _tmp_, \
&((sub)->test_list), test_list) { \
if (_test_->desc.id == tid) { \
list_del_init(&(_test_->test_list)); \
_flag_ = 1; \
} \
} \
spin_unlock(&((sub)->test_lock)); \
\
if (!_flag_) \
printk(KERN_ERR "splat: Error finalizing: " #tid "\n"); \
})
typedef int (*splat_test_func_t)(struct file *, void *);
typedef struct splat_test {
struct list_head test_list;
splat_user_t desc;
splat_test_func_t test;
} splat_test_t;
typedef struct splat_subsystem {
struct list_head subsystem_list;/* List had to chain entries */
splat_user_t desc;
spinlock_t test_lock;
struct list_head test_list;
} splat_subsystem_t;
#define SPLAT_INFO_BUFFER_SIZE 65536
#define SPLAT_INFO_BUFFER_REDZONE 256
typedef struct splat_info {
spinlock_t info_lock;
int info_size;
char *info_buffer;
char *info_head; /* Internal kernel use only */
} splat_info_t;
#define sym2str(sym) (char *)(#sym)
#define splat_print(file, format, args...) \
({ splat_info_t *_info_ = (splat_info_t *)file->private_data; \
int _rc_; \
\
ASSERT(_info_); \
ASSERT(_info_->info_buffer); \
\
spin_lock(&_info_->info_lock); \
\
/* Don't allow the kernel to start a write in the red zone */ \
if ((int)(_info_->info_head - _info_->info_buffer) > \
(SPLAT_INFO_BUFFER_SIZE - SPLAT_INFO_BUFFER_REDZONE)) { \
_rc_ = -EOVERFLOW; \
} else { \
_rc_ = sprintf(_info_->info_head, format, args); \
if (_rc_ >= 0) \
_info_->info_head += _rc_; \
} \
\
spin_unlock(&_info_->info_lock); \
_rc_; \
})
#define splat_vprint(file, test, format, args...) \
splat_print(file, "%*s: " format, SPLAT_NAME_SIZE, test, args)
#define splat_locked_test(lock, test) \
({ \
int _rc_; \
spin_lock(lock); \
_rc_ = (test) ? 1 : 0; \
spin_unlock(lock); \
_rc_; \
})
splat_subsystem_t *splat_condvar_init(void);
splat_subsystem_t *splat_kmem_init(void);
splat_subsystem_t *splat_mutex_init(void);
splat_subsystem_t *splat_krng_init(void);
splat_subsystem_t *splat_rwlock_init(void);
splat_subsystem_t *splat_taskq_init(void);
splat_subsystem_t *splat_thread_init(void);
splat_subsystem_t *splat_time_init(void);
splat_subsystem_t *splat_vnode_init(void);
splat_subsystem_t *splat_kobj_init(void);
splat_subsystem_t *splat_atomic_init(void);
splat_subsystem_t *splat_list_init(void);
splat_subsystem_t *splat_generic_init(void);
splat_subsystem_t *splat_cred_init(void);
void splat_condvar_fini(splat_subsystem_t *);
void splat_kmem_fini(splat_subsystem_t *);
void splat_mutex_fini(splat_subsystem_t *);
void splat_krng_fini(splat_subsystem_t *);
void splat_rwlock_fini(splat_subsystem_t *);
void splat_taskq_fini(splat_subsystem_t *);
void splat_thread_fini(splat_subsystem_t *);
void splat_time_fini(splat_subsystem_t *);
void splat_vnode_fini(splat_subsystem_t *);
void splat_kobj_fini(splat_subsystem_t *);
void splat_atomic_fini(splat_subsystem_t *);
void splat_list_fini(splat_subsystem_t *);
void splat_generic_fini(splat_subsystem_t *);
void splat_cred_fini(splat_subsystem_t *);
int splat_condvar_id(void);
int splat_kmem_id(void);
int splat_mutex_id(void);
int splat_krng_id(void);
int splat_rwlock_id(void);
int splat_taskq_id(void);
int splat_thread_id(void);
int splat_time_id(void);
int splat_vnode_id(void);
int splat_kobj_id(void);
int splat_atomic_id(void);
int splat_list_id(void);
int splat_generic_id(void);
int splat_cred_id(void);
#endif /* _SPLAT_INTERNAL_H */
Reference in New Issue View Git Blame Copy Permalink