Re: [PATCH] Convert idr's internal locking to _irqsave variant
From: Roland Dreier
Date: Mon Jul 17 2006 - 11:55:21 EST
> Problem is, I think, you'll need to preallocate IDR_FREE_MAX items. And
> then free them all again when none of them were consumed (usual).
Actually I think it's OK if we just pass in no more than one extra
layer for each try to add something with idr_get_new(). In the worst
case, this leads to a lot of extra calls to idr_get_new(), but in the
usual case it's fine.
I'm including a lightly tested big patch with all my idr changes for
comments -- I'll split it up into a form more suitable for merging.
(Some of the changes are unrelated and obviously good, eg using
kmem_cache_zalloc() instead of a slab cache with a constructor that
does memset(0)).
I'm not sure I'm thrilled with this approach, but it does seem to be a
net win. With an allyesconfig with debugging options turned off (so
spinlocks shrink back down to 8 bytes), I get the following:
text data bss dec hex filename
24347759 5971210 2322176 32641145 1f21079 vmlinux.old
24347370 5970474 2320704 32638548 1f20654 vmlinux.new
Most of the savings comes from ocfs2, which has a static array of
255 structures that each contain an idr -- so removing the lock from
struct idr saves 255 * 8 = 2040 bytes. However, even without
factoring that in, this does seem to be a net win:
add/remove: 2/4 grow/shrink: 23/51 up/down: 719/-3215 (-2496)
function old new delta
idr_get_new_above 38 554 +516
dm_create 957 1000 +43
ipath_init_one 3294 3329 +35
get_layer - 32 +32
idr_alloc_layer - 16 +16
sd_probe 871 881 +10
rtc_device_register 493 503 +10
proc_register 277 286 +9
mmc_add_host_sysfs 126 135 +9
idr_add_uobj 80 85 +5
cma_alloc_port 224 229 +5
sys_timer_create 876 880 +4
set_anon_super 173 177 +4
sctp_process_init 1312 1316 +4
ib_ucm_ctx_alloc 197 201 +4
ib_create_cm_id 287 290 +3
proc_mkdir_mode 95 97 +2
vfs_kern_mount 279 280 +1
send_mad 325 326 +1
proc_symlink 141 142 +1
proc_file_write 40 41 +1
kill_block_super 56 57 +1
get_sb_single 175 176 +1
free_proc_entry 108 109 +1
deactivate_super 126 127 +1
proc_readdir 353 352 -1
proc_getattr 40 39 -1
get_sb_nodev 150 149 -1
o2net_send_message_vec 2032 2030 -2
hwmon_device_register 198 196 -2
create_proc_entry 170 168 -2
__put_super_and_need_restart 54 52 -2
v9fs_read_work 1424 1421 -3
v9fs_mux_init 1333 1330 -3
v9fs_mux_flush_cb 303 300 -3
v9fs_mux_destroy 369 366 -3
v9fs_mux_cancel 382 379 -3
o2net_init 441 438 -3
inotify_add_watch 285 280 -5
v9fs_session_init 1490 1484 -6
unnamed_dev_idr 32 24 -8
unit_table 32 24 -8
tcp_ps 32 24 -8
sdp_ps 32 24 -8
sd_index_idr 32 24 -8
sctp_assocs_id 32 24 -8
rtc_idr 32 24 -8
query_idr 32 24 -8
proc_inum_idr 32 24 -8
posix_timers_id 32 24 -8
mmc_host_idr 32 24 -8
lpfc_hba_index 32 24 -8
ib_uverbs_srq_idr 32 24 -8
ib_uverbs_qp_idr 32 24 -8
ib_uverbs_pd_idr 32 24 -8
ib_uverbs_mw_idr 32 24 -8
ib_uverbs_mr_idr 32 24 -8
ib_uverbs_cq_idr 32 24 -8
ib_uverbs_ah_idr 32 24 -8
i2c_adapter_idr 32 24 -8
hwmon_idr 32 24 -8
ctx_id_table 32 24 -8
cm 112 104 -8
allocated_ptys 32 24 -8
_minor_idr 32 24 -8
i2c_add_adapter 494 484 -10
idr_cache_ctor 12 - -12
v9fs_get_idpool 149 134 -15
ib_cm_init 237 220 -17
free_layer 55 34 -21
idr_init 88 62 -26
idr_get_new 40 13 -27
idr_remove 357 328 -29
infinipath_init 227 197 -30
lpfc_pci_probe_one 2752 2710 -42
ptmx_open 427 379 -48
idr_pre_get 59 - -59
alloc_layer 66 - -66
idr_get_new_above_int 533 - -533
o2net_nodes 99960 97920 -2040
---
diff --git a/arch/powerpc/mm/mmu_context_64.c b/arch/powerpc/mm/mmu_context_64.c
index 90a06ac..85d6a03 100644
--- a/arch/powerpc/mm/mmu_context_64.c
+++ b/arch/powerpc/mm/mmu_context_64.c
@@ -26,20 +26,21 @@ static DEFINE_IDR(mmu_context_idr);
int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
+ struct idr_layer *layer = NULL;
int index;
int err;
again:
- if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL))
- return -ENOMEM;
-
spin_lock(&mmu_context_lock);
- err = idr_get_new_above(&mmu_context_idr, NULL, 1, &index);
+ err = idr_get_new_above(&mmu_context_idr, NULL, 1, &index, layer);
spin_unlock(&mmu_context_lock);
- if (err == -EAGAIN)
+ if (err == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return -ENOMEM;
goto again;
- else if (err)
+ } else if (err)
return err;
if (index > MAX_CONTEXT) {
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index bfdb902..0ae099e 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2135,6 +2135,7 @@ #ifdef CONFIG_UNIX98_PTYS
static int ptmx_open(struct inode * inode, struct file * filp)
{
struct tty_struct *tty;
+ struct idr_layer *layer = NULL;
int retval;
int index;
int idr_ret;
@@ -2143,24 +2144,27 @@ static int ptmx_open(struct inode * inod
/* find a device that is not in use. */
down(&allocated_ptys_lock);
- if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
- up(&allocated_ptys_lock);
- return -ENOMEM;
- }
- idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
- if (idr_ret < 0) {
- up(&allocated_ptys_lock);
- if (idr_ret == -EAGAIN)
- return -ENOMEM;
- return -EIO;
- }
- if (index >= pty_limit) {
- idr_remove(&allocated_ptys, index);
- up(&allocated_ptys_lock);
- return -EIO;
- }
+ do {
+ idr_ret = idr_get_new(&allocated_ptys, NULL, &index, layer);
+ if (idr_ret == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer) {
+ idr_ret = -ENOMEM;
+ break;
+ }
+ continue;
+ }
+
+ if (index >= pty_limit) {
+ idr_remove(&allocated_ptys, index);
+ idr_ret = -EIO;
+ }
+ } while (idr_ret == -EAGAIN);
up(&allocated_ptys_lock);
+ if (idr_ret)
+ return idr_ret == -EAGAIN ? -ENOMEM : -EIO;
+
mutex_lock(&tty_mutex);
retval = init_dev(ptm_driver, index, &tty);
mutex_unlock(&tty_mutex);
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 106fa01..82d6d04 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -38,20 +38,21 @@ static DEFINE_SPINLOCK(idr_lock);
*/
struct class_device *hwmon_device_register(struct device *dev)
{
+ struct idr_layer *layer = NULL;
struct class_device *cdev;
int id, err;
again:
- if (unlikely(idr_pre_get(&hwmon_idr, GFP_KERNEL) == 0))
- return ERR_PTR(-ENOMEM);
-
spin_lock(&idr_lock);
- err = idr_get_new(&hwmon_idr, NULL, &id);
+ err = idr_get_new(&hwmon_idr, NULL, &id, layer);
spin_unlock(&idr_lock);
- if (unlikely(err == -EAGAIN))
+ if (unlikely(err == -EAGAIN)) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return ERR_PTR(-ENOMEM);
goto again;
- else if (unlikely(err))
+ } else if (unlikely(err))
return ERR_PTR(err);
id = id & MAX_ID_MASK;
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 9cb277d..f8aa8ea 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -151,22 +151,24 @@ static struct device_attribute dev_attr_
int i2c_add_adapter(struct i2c_adapter *adap)
{
int id, res = 0;
+ struct idr_layer *layer = NULL;
struct list_head *item;
struct i2c_driver *driver;
mutex_lock(&core_lists);
- if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
- res = -ENOMEM;
- goto out_unlock;
- }
-
- res = idr_get_new(&i2c_adapter_idr, adap, &id);
- if (res < 0) {
- if (res == -EAGAIN)
+again:
+ res = idr_get_new(&i2c_adapter_idr, adap, &id, layer);
+ if (res == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer) {
res = -ENOMEM;
- goto out_unlock;
+ goto out_unlock;
+ }
+ goto again;
}
+ if (res < 0)
+ goto out_unlock;
adap->nr = id & MAX_ID_MASK;
mutex_init(&adap->bus_lock);
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index f85c97f..cf14d01 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -298,6 +298,7 @@ static int cm_init_av_by_path(struct ib_
static int cm_alloc_id(struct cm_id_private *cm_id_priv)
{
+ struct idr_layer *layer = NULL;
unsigned long flags;
int ret;
static int next_id;
@@ -305,9 +306,15 @@ static int cm_alloc_id(struct cm_id_priv
do {
spin_lock_irqsave(&cm.lock, flags);
ret = idr_get_new_above(&cm.local_id_table, cm_id_priv, next_id++,
- (__force int *) &cm_id_priv->id.local_id);
+ (__force int *) &cm_id_priv->id.local_id,
+ layer);
spin_unlock_irqrestore(&cm.lock, flags);
- } while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table, GFP_KERNEL) );
+ if (ret == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ ret = -ENOMEM;
+ }
+ } while (ret == -EAGAIN);
return ret;
}
@@ -3347,7 +3354,6 @@ static int __init ib_cm_init(void)
cm.remote_qp_table = RB_ROOT;
cm.remote_sidr_table = RB_ROOT;
idr_init(&cm.local_id_table);
- idr_pre_get(&cm.local_id_table, GFP_KERNEL);
cm.wq = create_workqueue("ib_cm");
if (!cm.wq)
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index d6f99d5..314b150 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1433,6 +1433,7 @@ static void cma_bind_port(struct rdma_bi
static int cma_alloc_port(struct idr *ps, struct rdma_id_private *id_priv,
unsigned short snum)
{
+ struct idr_layer *layer = NULL;
struct rdma_bind_list *bind_list;
int port, start, ret;
@@ -1443,8 +1444,13 @@ static int cma_alloc_port(struct idr *ps
start = snum ? snum : sysctl_local_port_range[0];
do {
- ret = idr_get_new_above(ps, bind_list, start, &port);
- } while ((ret == -EAGAIN) && idr_pre_get(ps, GFP_KERNEL));
+ ret = idr_get_new_above(ps, bind_list, start, &port, layer);
+ if (ret == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ ret = -ENOMEM;
+ }
+ } while (ret == -EAGAIN);
if (ret)
goto err;
diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index aeda484..824b652 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -490,17 +490,20 @@ static void init_mad(struct ib_sa_mad *m
static int send_mad(struct ib_sa_query *query, int timeout_ms, gfp_t gfp_mask)
{
+ struct idr_layer *layer = NULL;
unsigned long flags;
int ret, id;
retry:
- if (!idr_pre_get(&query_idr, gfp_mask))
- return -ENOMEM;
spin_lock_irqsave(&idr_lock, flags);
- ret = idr_get_new(&query_idr, query, &id);
+ ret = idr_get_new(&query_idr, query, &id, layer);
spin_unlock_irqrestore(&idr_lock, flags);
- if (ret == -EAGAIN)
- goto retry;
+ if (ret == -EAGAIN) {
+ layer = idr_alloc_layer(gfp_mask);
+ if (layer)
+ goto retry;
+ ret = -ENOMEM;
+ }
if (ret)
return ret;
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index c1c6fda..22d5e24 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -173,6 +173,7 @@ static void ib_ucm_cleanup_events(struct
static struct ib_ucm_context *ib_ucm_ctx_alloc(struct ib_ucm_file *file)
{
+ struct idr_layer *layer = NULL;
struct ib_ucm_context *ctx;
int result;
@@ -186,13 +187,15 @@ static struct ib_ucm_context *ib_ucm_ctx
INIT_LIST_HEAD(&ctx->events);
do {
- result = idr_pre_get(&ctx_id_table, GFP_KERNEL);
- if (!result)
- goto error;
-
mutex_lock(&ctx_id_mutex);
- result = idr_get_new(&ctx_id_table, ctx, &ctx->id);
+ result = idr_get_new(&ctx_id_table, ctx, &ctx->id, layer);
mutex_unlock(&ctx_id_mutex);
+
+ if (result == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ result = -ENOMEM;
+ }
} while (result == -EAGAIN);
if (result)
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index bdf5d50..71dea88 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -109,18 +109,20 @@ static void put_uobj_write(struct ib_uob
static int idr_add_uobj(struct idr *idr, struct ib_uobject *uobj)
{
+ struct idr_layer *layer = NULL;
int ret;
-retry:
- if (!idr_pre_get(idr, GFP_KERNEL))
- return -ENOMEM;
+ do {
+ spin_lock(&ib_uverbs_idr_lock);
+ ret = idr_get_new(idr, uobj, &uobj->id, layer);
+ spin_unlock(&ib_uverbs_idr_lock);
- spin_lock(&ib_uverbs_idr_lock);
- ret = idr_get_new(idr, uobj, &uobj->id);
- spin_unlock(&ib_uverbs_idr_lock);
-
- if (ret == -EAGAIN)
- goto retry;
+ if (ret == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ ret = -ENOMEM;
+ }
+ } while (ret == -EAGAIN);
return ret;
}
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index 823131d..6f2a711 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -168,15 +168,11 @@ static void ipath_free_devdata(struct pc
static struct ipath_devdata *ipath_alloc_devdata(struct pci_dev *pdev)
{
+ struct idr_layer *layer = NULL;
unsigned long flags;
struct ipath_devdata *dd;
int ret;
- if (!idr_pre_get(&unit_table, GFP_KERNEL)) {
- dd = ERR_PTR(-ENOMEM);
- goto bail;
- }
-
dd = vmalloc(sizeof(*dd));
if (!dd) {
dd = ERR_PTR(-ENOMEM);
@@ -187,7 +183,19 @@ static struct ipath_devdata *ipath_alloc
spin_lock_irqsave(&ipath_devs_lock, flags);
- ret = idr_get_new(&unit_table, dd, &dd->ipath_unit);
+ do {
+ ret = idr_get_new(&unit_table, dd, &dd->ipath_unit, layer);
+ if (ret == -EAGAIN) {
+ spin_unlock_irqrestore(&ipath_devs_lock, flags);
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer) {
+ dd = ERR_PTR(-ENOMEM);
+ goto bail;
+ }
+ spin_lock_irqsave(&ipath_devs_lock, flags);
+ }
+ } while (ret == -EAGAIN);
+
if (ret < 0) {
printk(KERN_ERR IPATH_DRV_NAME
": Could not allocate unit ID: error %d\n", -ret);
@@ -1754,10 +1762,6 @@ static int __init infinipath_init(void)
* the PCI subsystem.
*/
idr_init(&unit_table);
- if (!idr_pre_get(&unit_table, GFP_KERNEL)) {
- ret = -ENOMEM;
- goto bail;
- }
ret = pci_register_driver(&ipath_driver);
if (ret < 0) {
@@ -1780,7 +1784,7 @@ static int __init infinipath_init(void)
goto bail_group;
}
- goto bail;
+ return ret;
bail_group:
ipath_driver_remove_group(&ipath_driver.driver);
@@ -1791,7 +1795,6 @@ bail_pci:
bail_unit:
idr_destroy(&unit_table);
-bail:
return ret;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c99bf9f..e2dd20a 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -807,23 +807,30 @@ static void free_minor(int minor)
*/
static int specific_minor(struct mapped_device *md, int minor)
{
+ struct idr_layer *layer = NULL;
int r, m;
if (minor >= (1 << MINORBITS))
return -EINVAL;
- r = idr_pre_get(&_minor_idr, GFP_KERNEL);
- if (!r)
- return -ENOMEM;
-
spin_lock(&_minor_lock);
+again:
if (idr_find(&_minor_idr, minor)) {
r = -EBUSY;
goto out;
}
- r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);
+ r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m, layer);
+ if (r == -EAGAIN) {
+ spin_unlock(&_minor_lock);
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return -ENOMEM;
+
+ spin_lock(&_minor_lock);
+ goto again;
+ }
if (r)
goto out;
@@ -840,18 +847,21 @@ out:
static int next_free_minor(struct mapped_device *md, int *minor)
{
+ struct idr_layer *layer = NULL;
int r, m;
- r = idr_pre_get(&_minor_idr, GFP_KERNEL);
- if (!r)
- return -ENOMEM;
-
+again:
spin_lock(&_minor_lock);
-
- r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m);
- if (r) {
- goto out;
+ r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m, layer);
+ if (r == -EAGAIN) {
+ spin_unlock(&_minor_lock);
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return -ENOMEM;
+ goto again;
}
+ if (r)
+ goto out;
if (m >= (1 << MINORBITS)) {
idr_remove(&_minor_idr, m);
diff --git a/drivers/mmc/mmc_sysfs.c b/drivers/mmc/mmc_sysfs.c
index a2a35fd..bf61ff4 100644
--- a/drivers/mmc/mmc_sysfs.c
+++ b/drivers/mmc/mmc_sysfs.c
@@ -280,14 +280,19 @@ struct mmc_host *mmc_alloc_host_sysfs(in
*/
int mmc_add_host_sysfs(struct mmc_host *host)
{
+ struct idr_layer *layer = NULL;
int err;
- if (!idr_pre_get(&mmc_host_idr, GFP_KERNEL))
- return -ENOMEM;
-
+again:
spin_lock(&mmc_host_lock);
- err = idr_get_new(&mmc_host_idr, host, &host->index);
+ err = idr_get_new(&mmc_host_idr, host, &host->index, layer);
spin_unlock(&mmc_host_lock);
+ if (err == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return -ENOMEM;
+ goto again;
+ }
if (err)
return err;
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 1cb61a7..3388059 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -42,19 +42,21 @@ struct rtc_device *rtc_device_register(c
struct rtc_class_ops *ops,
struct module *owner)
{
+ struct idr_layer *layer = NULL;
struct rtc_device *rtc;
int id, err;
- if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
- err = -ENOMEM;
- goto exit;
- }
-
-
+again:
mutex_lock(&idr_lock);
- err = idr_get_new(&rtc_idr, NULL, &id);
+ err = idr_get_new(&rtc_idr, NULL, &id, layer);
mutex_unlock(&idr_lock);
+ if (err == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return ERR_PTR(-ENOMEM);
+ goto again;
+ }
if (err < 0)
goto exit;
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 81755a3..401608b 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -1421,6 +1421,7 @@ lpfc_pci_probe_one(struct pci_dev *pdev,
struct lpfc_hba *phba;
struct lpfc_sli *psli;
struct lpfc_iocbq *iocbq_entry = NULL, *iocbq_next = NULL;
+ struct idr_layer *layer = NULL;
unsigned long bar0map_len, bar2map_len;
int error = -ENODEV, retval;
int i;
@@ -1443,10 +1444,16 @@ lpfc_pci_probe_one(struct pci_dev *pdev,
phba->pcidev = pdev;
/* Assign an unused board number */
- if (!idr_pre_get(&lpfc_hba_index, GFP_KERNEL))
- goto out_put_host;
-
- error = idr_get_new(&lpfc_hba_index, NULL, &phba->brd_no);
+again:
+ error = idr_get_new(&lpfc_hba_index, NULL, &phba->brd_no, layer);
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer) {
+ error = -ENOMEM;
+ goto out_put_host;
+ }
+ goto again;
+ }
if (error)
goto out_put_host;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3225d31..fe504be 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1617,6 +1617,7 @@ static int sd_probe(struct device *dev)
struct scsi_device *sdp = to_scsi_device(dev);
struct scsi_disk *sdkp;
struct gendisk *gd;
+ struct idr_layer *layer = NULL;
u32 index;
int error;
@@ -1636,13 +1637,19 @@ static int sd_probe(struct device *dev)
if (!gd)
goto out_free;
- if (!idr_pre_get(&sd_index_idr, GFP_KERNEL))
- goto out_put;
-
+again:
spin_lock(&sd_index_lock);
- error = idr_get_new(&sd_index_idr, NULL, &index);
+ error = idr_get_new(&sd_index_idr, NULL, &index, layer);
spin_unlock(&sd_index_lock);
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer) {
+ error = -ENOMEM;
+ goto out_put;
+ }
+ goto again;
+ }
if (index >= SD_MAX_DISKS)
error = -EBUSY;
if (error)
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 22f7ccd..d03c3ba 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -198,25 +198,26 @@ struct v9fs_session_info *v9fs_inode2v9s
int v9fs_get_idpool(struct v9fs_idpool *p)
{
+ struct idr_layer *layer = NULL;
int i = 0;
int error;
retry:
- if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
- return 0;
-
if (down_interruptible(&p->lock) == -EINTR) {
eprintk(KERN_WARNING, "Interrupted while locking\n");
return -1;
}
/* no need to store exactly p, we just need something non-null */
- error = idr_get_new(&p->pool, p, &i);
+ error = idr_get_new(&p->pool, p, &i, layer);
up(&p->lock);
- if (error == -EAGAIN)
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return -1;
goto retry;
- else if (error)
+ } else if (error)
return -1;
return i;
diff --git a/fs/inotify.c b/fs/inotify.c
index 723836a..7e12bed 100644
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -131,12 +131,16 @@ EXPORT_SYMBOL_GPL(put_inotify_watch);
static int inotify_handle_get_wd(struct inotify_handle *ih,
struct inotify_watch *watch)
{
+ struct idr_layer *layer = NULL;
int ret;
do {
- if (unlikely(!idr_pre_get(&ih->idr, GFP_KERNEL)))
- return -ENOSPC;
- ret = idr_get_new_above(&ih->idr, watch, ih->last_wd+1, &watch->wd);
+ ret = idr_get_new_above(&ih->idr, watch, ih->last_wd+1, &watch->wd, layer);
+ if (ret == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ ret = -ENOSPC;
+ }
} while (ret == -EAGAIN);
if (likely(!ret))
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index b650efa..f9d1b04 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -175,19 +175,21 @@ static u8 o2net_num_from_nn(struct o2net
static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
{
+ struct idr_layer *layer = NULL;
int ret = 0;
do {
- if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) {
- ret = -EAGAIN;
- break;
- }
spin_lock(&nn->nn_lock);
- ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id);
+ ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id, layer);
if (ret == 0)
list_add_tail(&nsw->ns_node_item,
&nn->nn_status_list);
spin_unlock(&nn->nn_lock);
+ if (ret == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_ATOMIC);
+ if (!layer)
+ ret = -ENOMEM;
+ }
} while (ret == -EAGAIN);
if (ret == 0) {
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 4ba0300..60bdd42 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -318,19 +318,20 @@ #define PROC_DYNAMIC_FIRST 0xF0000000UL
*/
static unsigned int get_inode_number(void)
{
+ struct idr_layer *layer = NULL;
int i, inum = 0;
int error;
retry:
- if (idr_pre_get(&proc_inum_idr, GFP_KERNEL) == 0)
- return 0;
-
spin_lock(&proc_inum_lock);
- error = idr_get_new(&proc_inum_idr, NULL, &i);
+ error = idr_get_new(&proc_inum_idr, NULL, &i, layer);
spin_unlock(&proc_inum_lock);
- if (error == -EAGAIN)
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (!layer)
+ return 0;
goto retry;
- else if (error)
+ } else if (error)
return 0;
inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST;
diff --git a/fs/super.c b/fs/super.c
index 6d4e817..67455f5 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -607,19 +607,20 @@ static DEFINE_SPINLOCK(unnamed_dev_lock)
int set_anon_super(struct super_block *s, void *data)
{
+ struct idr_layer *layer = NULL;
int dev;
int error;
retry:
- if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0)
- return -ENOMEM;
spin_lock(&unnamed_dev_lock);
- error = idr_get_new(&unnamed_dev_idr, NULL, &dev);
+ error = idr_get_new(&unnamed_dev_idr, NULL, &dev, layer);
spin_unlock(&unnamed_dev_lock);
- if (error == -EAGAIN)
- /* We raced and lost with another CPU. */
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_ATOMIC);
+ if (!layer)
+ return -ENOMEM;
goto retry;
- else if (error)
+ } else if (error)
return -EAGAIN;
if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 8268034..de34c4e 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -44,7 +44,7 @@ #define MAX_ID_MASK (MAX_ID_BIT - 1)
#define MAX_LEVEL (MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS
/* Number of id_layer structs to leave in free list */
-#define IDR_FREE_MAX MAX_LEVEL + MAX_LEVEL
+#define IDR_FREE_MAX (MAX_LEVEL + MAX_LEVEL)
struct idr_layer {
unsigned long bitmap; /* A zero bit means "space here" */
@@ -57,7 +57,6 @@ struct idr {
struct idr_layer *id_free;
int layers;
int id_free_cnt;
- spinlock_t lock;
};
#define IDR_INIT(name) \
@@ -66,7 +65,6 @@ #define IDR_INIT(name) \
.id_free = NULL, \
.layers = 0, \
.id_free_cnt = 0, \
- .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
}
#define DEFINE_IDR(name) struct idr name = IDR_INIT(name)
@@ -75,9 +73,10 @@ #define DEFINE_IDR(name) struct idr name
*/
void *idr_find(struct idr *idp, int id);
-int idr_pre_get(struct idr *idp, gfp_t gfp_mask);
-int idr_get_new(struct idr *idp, void *ptr, int *id);
-int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
+struct idr_layer *idr_alloc_layer(gfp_t gfp_mask);
+int idr_get_new(struct idr *idp, void *ptr, int *id, struct idr_layer *layer);
+int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id,
+ struct idr_layer *layer);
void *idr_replace(struct idr *idp, void *ptr, int id);
void idr_remove(struct idr *idp, int id);
void idr_destroy(struct idr *idp);
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index ac6dc87..18891b2 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -434,6 +434,7 @@ sys_timer_create(const clockid_t which_c
struct sigevent __user *timer_event_spec,
timer_t __user * created_timer_id)
{
+ struct idr_layer *layer = NULL;
int error = 0;
struct k_itimer *new_timer = NULL;
int new_timer_id;
@@ -451,17 +452,16 @@ sys_timer_create(const clockid_t which_c
spin_lock_init(&new_timer->it_lock);
retry:
- if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
- error = -EAGAIN;
- goto out;
- }
spin_lock_irq(&idr_lock);
error = idr_get_new(&posix_timers_id, (void *) new_timer,
- &new_timer_id);
+ &new_timer_id, layer);
spin_unlock_irq(&idr_lock);
- if (error == -EAGAIN)
- goto retry;
- else if (error) {
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(GFP_KERNEL);
+ if (layer)
+ goto retry;
+ }
+ if (error) {
/*
* Wierd looking, but we return EAGAIN if the IDR is
* full (proper POSIX return value for this)
diff --git a/lib/idr.c b/lib/idr.c
index 16d2143..187ce4d 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -35,65 +35,39 @@ #include <linux/idr.h>
static kmem_cache_t *idr_layer_cache;
-static struct idr_layer *alloc_layer(struct idr *idp)
+static struct idr_layer *get_layer(struct idr *idp)
{
struct idr_layer *p;
- unsigned long flags;
- spin_lock_irqsave(&idp->lock, flags);
- if ((p = idp->id_free)) {
+ p = idp->id_free;
+ if (p) {
idp->id_free = p->ary[0];
idp->id_free_cnt--;
p->ary[0] = NULL;
}
- spin_unlock_irqrestore(&idp->lock, flags);
- return(p);
-}
-/* only called when idp->lock is held */
-static void __free_layer(struct idr *idp, struct idr_layer *p)
-{
- p->ary[0] = idp->id_free;
- idp->id_free = p;
- idp->id_free_cnt++;
+ return p;
}
static void free_layer(struct idr *idp, struct idr_layer *p)
{
- unsigned long flags;
-
- /*
- * Depends on the return element being zeroed.
- */
- spin_lock_irqsave(&idp->lock, flags);
- __free_layer(idp, p);
- spin_unlock_irqrestore(&idp->lock, flags);
+ if (idp->id_free_cnt < IDR_FREE_MAX) {
+ p->ary[0] = idp->id_free;
+ idp->id_free = p;
+ idp->id_free_cnt++;
+ } else
+ kmem_cache_free(idr_layer_cache, p);
}
/**
- * idr_pre_get - reserver resources for idr allocation
- * @idp: idr handle
+ * idr_alloc_layer - reserve resources for idr allocation
* @gfp_mask: memory allocation flags
- *
- * This function should be called prior to locking and calling the
- * following function. It preallocates enough memory to satisfy
- * the worst possible allocation.
- *
- * If the system is REALLY out of memory this function returns 0,
- * otherwise 1.
*/
-int idr_pre_get(struct idr *idp, gfp_t gfp_mask)
+struct idr_layer *idr_alloc_layer(gfp_t gfp_mask)
{
- while (idp->id_free_cnt < IDR_FREE_MAX) {
- struct idr_layer *new;
- new = kmem_cache_alloc(idr_layer_cache, gfp_mask);
- if (new == NULL)
- return (0);
- free_layer(idp, new);
- }
- return 1;
+ return kmem_cache_zalloc(idr_layer_cache, gfp_mask);
}
-EXPORT_SYMBOL(idr_pre_get);
+EXPORT_SYMBOL(idr_alloc_layer);
static int sub_alloc(struct idr *idp, void *ptr, int *starting_id)
{
@@ -136,7 +110,7 @@ static int sub_alloc(struct idr *idp, vo
* Create the layer below if it is missing.
*/
if (!p->ary[m]) {
- if (!(new = alloc_layer(idp)))
+ if (!(new = get_layer(idp)))
return -1;
p->ary[m] = new;
p->count++;
@@ -171,14 +145,13 @@ static int idr_get_new_above_int(struct
{
struct idr_layer *p, *new;
int layers, v, id;
- unsigned long flags;
id = starting_id;
build_up:
p = idp->top;
layers = idp->layers;
if (unlikely(!p)) {
- if (!(p = alloc_layer(idp)))
+ if (!(p = get_layer(idp)))
return -1;
layers = 1;
}
@@ -190,19 +163,17 @@ build_up:
layers++;
if (!p->count)
continue;
- if (!(new = alloc_layer(idp))) {
+ if (!(new = get_layer(idp))) {
/*
* The allocation failed. If we built part of
* the structure tear it down.
*/
- spin_lock_irqsave(&idp->lock, flags);
for (new = p; p && p != idp->top; new = p) {
p = p->ary[0];
new->ary[0] = NULL;
new->bitmap = new->count = 0;
- __free_layer(idp, new);
+ free_layer(idp, new);
}
- spin_unlock_irqrestore(&idp->lock, flags);
return -1;
}
new->ary[0] = p;
@@ -216,7 +187,7 @@ build_up:
v = sub_alloc(idp, ptr, &id);
if (v == -2)
goto build_up;
- return(v);
+ return v;
}
/**
@@ -225,20 +196,25 @@ build_up:
* @ptr: pointer you want associated with the ide
* @start_id: id to start search at
* @id: pointer to the allocated handle
+ * @layer: pointer to extra storage
*
* This is the allocate id function. It should be called with any
* required locks.
*
* If memory is required, it will return -EAGAIN, you should unlock
- * and go back to the idr_pre_get() call. If the idr is full, it will
- * return -ENOSPC.
+ * and call idr_alloc_layer() to get a new layer to pass in as the
+ * @layer parameter. If the idr is full, it will return -ENOSPC.
*
* @id returns a value in the range 0 ... 0x7fffffff
*/
-int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id)
+int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id,
+ struct idr_layer *layer)
{
int rv;
+ if (layer)
+ free_layer(idp, layer);
+
rv = idr_get_new_above_int(idp, ptr, starting_id);
/*
* This is a cheap hack until the IDR code can be fixed to
@@ -260,33 +236,20 @@ EXPORT_SYMBOL(idr_get_new_above);
* @idp: idr handle
* @ptr: pointer you want associated with the ide
* @id: pointer to the allocated handle
+ * @layer: pointer to extra storage
*
* This is the allocate id function. It should be called with any
* required locks.
*
* If memory is required, it will return -EAGAIN, you should unlock
- * and go back to the idr_pre_get() call. If the idr is full, it will
- * return -ENOSPC.
+ * and call idr_alloc_layer() to get a new layer to pass in as the
+ * @layer parameter. If the idr is full, it will return -ENOSPC.
*
* @id returns a value in the range 0 ... 0x7fffffff
*/
-int idr_get_new(struct idr *idp, void *ptr, int *id)
+int idr_get_new(struct idr *idp, void *ptr, int *id, struct idr_layer *layer)
{
- int rv;
-
- rv = idr_get_new_above_int(idp, ptr, 0);
- /*
- * This is a cheap hack until the IDR code can be fixed to
- * return proper error values.
- */
- if (rv < 0) {
- if (rv == -1)
- return -EAGAIN;
- else /* Will be -3 */
- return -ENOSPC;
- }
- *id = rv;
- return 0;
+ return idr_get_new_above(idp, ptr, 0, id, layer);
}
EXPORT_SYMBOL(idr_get_new);
@@ -349,11 +312,6 @@ void idr_remove(struct idr *idp, int id)
idp->top = p;
--idp->layers;
}
- while (idp->id_free_cnt >= IDR_FREE_MAX) {
- p = alloc_layer(idp);
- kmem_cache_free(idr_layer_cache, p);
- return;
- }
}
EXPORT_SYMBOL(idr_remove);
@@ -364,7 +322,7 @@ EXPORT_SYMBOL(idr_remove);
void idr_destroy(struct idr *idp)
{
while (idp->id_free_cnt) {
- struct idr_layer *p = alloc_layer(idp);
+ struct idr_layer *p = get_layer(idp);
kmem_cache_free(idr_layer_cache, p);
}
}
@@ -445,17 +403,11 @@ void *idr_replace(struct idr *idp, void
}
EXPORT_SYMBOL(idr_replace);
-static void idr_cache_ctor(void * idr_layer, kmem_cache_t *idr_layer_cache,
- unsigned long flags)
-{
- memset(idr_layer, 0, sizeof(struct idr_layer));
-}
-
static int init_id_cache(void)
{
if (!idr_layer_cache)
idr_layer_cache = kmem_cache_create("idr_layer_cache",
- sizeof(struct idr_layer), 0, 0, idr_cache_ctor, NULL);
+ sizeof(struct idr_layer), 0, 0, NULL, NULL);
return 0;
}
@@ -470,6 +422,5 @@ void idr_init(struct idr *idp)
{
init_id_cache();
memset(idp, 0, sizeof(struct idr));
- spin_lock_init(&idp->lock);
}
EXPORT_SYMBOL(idr_init);
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 2a87736..fc712c4 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1928,6 +1928,7 @@ int sctp_process_init(struct sctp_associ
* association.
*/
if (!asoc->temp) {
+ struct idr_layer *layer = NULL;
int assoc_id;
int error;
@@ -1937,15 +1938,16 @@ int sctp_process_init(struct sctp_associ
goto clean_up;
retry:
- if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
- goto clean_up;
spin_lock_bh(&sctp_assocs_id_lock);
error = idr_get_new_above(&sctp_assocs_id, (void *)asoc, 1,
- &assoc_id);
+ &assoc_id, layer);
spin_unlock_bh(&sctp_assocs_id_lock);
- if (error == -EAGAIN)
- goto retry;
- else if (error)
+ if (error == -EAGAIN) {
+ layer = idr_alloc_layer(gfp);
+ if (layer)
+ goto retry;
+ }
+ if (error)
goto clean_up;
asoc->assoc_id = (sctp_assoc_t) assoc_id;
-
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