* [PATCH] adjust a few RCU domain locking calls
@ 2012-09-07 12:56 Jan Beulich
2012-09-07 14:47 ` Keir Fraser
0 siblings, 1 reply; 2+ messages in thread
From: Jan Beulich @ 2012-09-07 12:56 UTC (permalink / raw)
To: xen-devel
[-- Attachment #1: Type: text/plain, Size: 7668 bytes --]
x86's do_physdev_op() had a case where the locking was entirely
superfluous. Its physdev_map_pirq() further had a case where the lock
was being obtained too early, needlessly complicating early exit paths.
Grant table code had two open coded instances of
rcu_lock_target_domain_by_id(), and a third code section could be
consolidated by using the newly introduced helper function.
The memory hypercall code had two more instances of open coding
rcu_lock_target_domain_by_id(), but note that here this is not just
cleanup, but also fixes an error return path in memory_exchange() to
actually return an error.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -90,14 +90,10 @@ static int physdev_hvm_map_pirq(
int physdev_map_pirq(domid_t domid, int type, int *index, int *pirq_p,
struct msi_info *msi)
{
- struct domain *d;
+ struct domain *d = current->domain;
int pirq, irq, ret = 0;
void *map_data = NULL;
- ret = rcu_lock_target_domain_by_id(domid, &d);
- if ( ret )
- return ret;
-
if ( domid == DOMID_SELF && is_hvm_domain(d) )
{
/*
@@ -105,14 +101,15 @@ int physdev_map_pirq(domid_t domid, int
* calls back into itself and deadlocks on hvm_domain.irq_lock.
*/
if ( !is_hvm_pv_evtchn_domain(d) )
- {
- ret = -EINVAL;
- goto free_domain;
- }
- ret = physdev_hvm_map_pirq(d, type, index, pirq_p);
- goto free_domain;
+ return -EINVAL;
+
+ return physdev_hvm_map_pirq(d, type, index, pirq_p);
}
+ ret = rcu_lock_target_domain_by_id(domid, &d);
+ if ( ret )
+ return ret;
+
if ( !IS_PRIV_FOR(current->domain, d) )
{
ret = -EPERM;
@@ -696,13 +693,12 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
}
case PHYSDEVOP_get_free_pirq: {
struct physdev_get_free_pirq out;
- struct domain *d;
+ struct domain *d = v->domain;
ret = -EFAULT;
if ( copy_from_guest(&out, arg, 1) != 0 )
break;
- d = rcu_lock_current_domain();
spin_lock(&d->event_lock);
ret = get_free_pirq(d, out.type);
@@ -717,7 +713,6 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
}
spin_unlock(&d->event_lock);
- rcu_unlock_domain(d);
if ( ret >= 0 )
{
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -24,7 +24,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
-#include <xen/config.h>
+#include <xen/err.h>
#include <xen/iocap.h>
#include <xen/lib.h>
#include <xen/sched.h>
@@ -195,6 +195,30 @@ double_gt_unlock(struct grant_table *lgt
spin_unlock(&rgt->lock);
}
+static struct domain *gt_lock_target_domain_by_id(domid_t dom)
+{
+ struct domain *d;
+ int rc = GNTST_general_error;
+
+ switch ( rcu_lock_target_domain_by_id(dom, &d) )
+ {
+ case 0:
+ return d;
+
+ case -ESRCH:
+ gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
+ rc = GNTST_bad_domain;
+ break;
+
+ case -EPERM:
+ rc = GNTST_permission_denied;
+ break;
+ }
+
+ ASSERT(rc < 0 && -rc <= MAX_ERRNO);
+ return ERR_PTR(rc);
+}
+
static inline int
__get_maptrack_handle(
struct grant_table *t)
@@ -1261,7 +1285,6 @@ gnttab_setup_table(
struct grant_table *gt;
int i;
unsigned long gmfn;
- domid_t dom;
if ( count != 1 )
return -EINVAL;
@@ -1281,25 +1304,11 @@ gnttab_setup_table(
goto out1;
}
- dom = op.dom;
- if ( dom == DOMID_SELF )
+ d = gt_lock_target_domain_by_id(op.dom);
+ if ( IS_ERR(d) )
{
- d = rcu_lock_current_domain();
- }
- else
- {
- if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
- {
- gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
- op.status = GNTST_bad_domain;
- goto out1;
- }
-
- if ( unlikely(!IS_PRIV_FOR(current->domain, d)) )
- {
- op.status = GNTST_permission_denied;
- goto out2;
- }
+ op.status = PTR_ERR(d);
+ goto out1;
}
if ( xsm_grant_setup(current->domain, d) )
@@ -1352,7 +1361,6 @@ gnttab_query_size(
{
struct gnttab_query_size op;
struct domain *d;
- domid_t dom;
int rc;
if ( count != 1 )
@@ -1364,25 +1372,11 @@ gnttab_query_size(
return -EFAULT;
}
- dom = op.dom;
- if ( dom == DOMID_SELF )
- {
- d = rcu_lock_current_domain();
- }
- else
+ d = gt_lock_target_domain_by_id(op.dom);
+ if ( IS_ERR(d) )
{
- if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
- {
- gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
- op.status = GNTST_bad_domain;
- goto query_out;
- }
-
- if ( unlikely(!IS_PRIV_FOR(current->domain, d)) )
- {
- op.status = GNTST_permission_denied;
- goto query_out_unlock;
- }
+ op.status = PTR_ERR(d);
+ goto query_out;
}
rc = xsm_grant_query_size(current->domain, d);
@@ -2240,15 +2234,10 @@ gnttab_get_status_frames(XEN_GUEST_HANDL
return -EFAULT;
}
- rc = rcu_lock_target_domain_by_id(op.dom, &d);
- if ( rc < 0 )
+ d = gt_lock_target_domain_by_id(op.dom);
+ if ( IS_ERR(d) )
{
- if ( rc == -ESRCH )
- op.status = GNTST_bad_domain;
- else if ( rc == -EPERM )
- op.status = GNTST_permission_denied;
- else
- op.status = GNTST_general_error;
+ op.status = PTR_ERR(d);
goto out1;
}
rc = xsm_grant_setup(current->domain, d);
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -329,22 +329,9 @@ static long memory_exchange(XEN_GUEST_HA
out_chunk_order = exch.in.extent_order - exch.out.extent_order;
}
- if ( likely(exch.in.domid == DOMID_SELF) )
- {
- d = rcu_lock_current_domain();
- }
- else
- {
- if ( (d = rcu_lock_domain_by_id(exch.in.domid)) == NULL )
- goto fail_early;
-
- if ( !IS_PRIV_FOR(current->domain, d) )
- {
- rcu_unlock_domain(d);
- rc = -EPERM;
- goto fail_early;
- }
- }
+ rc = rcu_lock_target_domain_by_id(exch.in.domid, &d);
+ if ( rc )
+ goto fail_early;
memflags |= MEMF_bits(domain_clamp_alloc_bitsize(
d,
@@ -583,20 +570,8 @@ long do_memory_op(unsigned long cmd, XEN
&& (reservation.mem_flags & XENMEMF_populate_on_demand) )
args.memflags |= MEMF_populate_on_demand;
- if ( likely(reservation.domid == DOMID_SELF) )
- {
- d = rcu_lock_current_domain();
- }
- else
- {
- if ( (d = rcu_lock_domain_by_id(reservation.domid)) == NULL )
- return start_extent;
- if ( !IS_PRIV_FOR(current->domain, d) )
- {
- rcu_unlock_domain(d);
- return start_extent;
- }
- }
+ if ( unlikely(rcu_lock_target_domain_by_id(reservation.domid, &d)) )
+ return start_extent;
args.domain = d;
rc = xsm_memory_adjust_reservation(current->domain, d);
[-- Attachment #2: adjust-rcu-lock-domain.patch --]
[-- Type: text/plain, Size: 7705 bytes --]
adjust a few RCU domain locking calls
x86's do_physdev_op() had a case where the locking was entirely
superfluous. Its physdev_map_pirq() further had a case where the lock
was being obtained too early, needlessly complicating early exit paths.
Grant table code had two open coded instances of
rcu_lock_target_domain_by_id(), and a third code section could be
consolidated by using the newly introduced helper function.
The memory hypercall code had two more instances of open coding
rcu_lock_target_domain_by_id(), but note that here this is not just
cleanup, but also fixes an error return path in memory_exchange() to
actually return an error.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -90,14 +90,10 @@ static int physdev_hvm_map_pirq(
int physdev_map_pirq(domid_t domid, int type, int *index, int *pirq_p,
struct msi_info *msi)
{
- struct domain *d;
+ struct domain *d = current->domain;
int pirq, irq, ret = 0;
void *map_data = NULL;
- ret = rcu_lock_target_domain_by_id(domid, &d);
- if ( ret )
- return ret;
-
if ( domid == DOMID_SELF && is_hvm_domain(d) )
{
/*
@@ -105,14 +101,15 @@ int physdev_map_pirq(domid_t domid, int
* calls back into itself and deadlocks on hvm_domain.irq_lock.
*/
if ( !is_hvm_pv_evtchn_domain(d) )
- {
- ret = -EINVAL;
- goto free_domain;
- }
- ret = physdev_hvm_map_pirq(d, type, index, pirq_p);
- goto free_domain;
+ return -EINVAL;
+
+ return physdev_hvm_map_pirq(d, type, index, pirq_p);
}
+ ret = rcu_lock_target_domain_by_id(domid, &d);
+ if ( ret )
+ return ret;
+
if ( !IS_PRIV_FOR(current->domain, d) )
{
ret = -EPERM;
@@ -696,13 +693,12 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
}
case PHYSDEVOP_get_free_pirq: {
struct physdev_get_free_pirq out;
- struct domain *d;
+ struct domain *d = v->domain;
ret = -EFAULT;
if ( copy_from_guest(&out, arg, 1) != 0 )
break;
- d = rcu_lock_current_domain();
spin_lock(&d->event_lock);
ret = get_free_pirq(d, out.type);
@@ -717,7 +713,6 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
}
spin_unlock(&d->event_lock);
- rcu_unlock_domain(d);
if ( ret >= 0 )
{
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -24,7 +24,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
-#include <xen/config.h>
+#include <xen/err.h>
#include <xen/iocap.h>
#include <xen/lib.h>
#include <xen/sched.h>
@@ -195,6 +195,30 @@ double_gt_unlock(struct grant_table *lgt
spin_unlock(&rgt->lock);
}
+static struct domain *gt_lock_target_domain_by_id(domid_t dom)
+{
+ struct domain *d;
+ int rc = GNTST_general_error;
+
+ switch ( rcu_lock_target_domain_by_id(dom, &d) )
+ {
+ case 0:
+ return d;
+
+ case -ESRCH:
+ gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
+ rc = GNTST_bad_domain;
+ break;
+
+ case -EPERM:
+ rc = GNTST_permission_denied;
+ break;
+ }
+
+ ASSERT(rc < 0 && -rc <= MAX_ERRNO);
+ return ERR_PTR(rc);
+}
+
static inline int
__get_maptrack_handle(
struct grant_table *t)
@@ -1261,7 +1285,6 @@ gnttab_setup_table(
struct grant_table *gt;
int i;
unsigned long gmfn;
- domid_t dom;
if ( count != 1 )
return -EINVAL;
@@ -1281,25 +1304,11 @@ gnttab_setup_table(
goto out1;
}
- dom = op.dom;
- if ( dom == DOMID_SELF )
+ d = gt_lock_target_domain_by_id(op.dom);
+ if ( IS_ERR(d) )
{
- d = rcu_lock_current_domain();
- }
- else
- {
- if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
- {
- gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
- op.status = GNTST_bad_domain;
- goto out1;
- }
-
- if ( unlikely(!IS_PRIV_FOR(current->domain, d)) )
- {
- op.status = GNTST_permission_denied;
- goto out2;
- }
+ op.status = PTR_ERR(d);
+ goto out1;
}
if ( xsm_grant_setup(current->domain, d) )
@@ -1352,7 +1361,6 @@ gnttab_query_size(
{
struct gnttab_query_size op;
struct domain *d;
- domid_t dom;
int rc;
if ( count != 1 )
@@ -1364,25 +1372,11 @@ gnttab_query_size(
return -EFAULT;
}
- dom = op.dom;
- if ( dom == DOMID_SELF )
- {
- d = rcu_lock_current_domain();
- }
- else
+ d = gt_lock_target_domain_by_id(op.dom);
+ if ( IS_ERR(d) )
{
- if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
- {
- gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
- op.status = GNTST_bad_domain;
- goto query_out;
- }
-
- if ( unlikely(!IS_PRIV_FOR(current->domain, d)) )
- {
- op.status = GNTST_permission_denied;
- goto query_out_unlock;
- }
+ op.status = PTR_ERR(d);
+ goto query_out;
}
rc = xsm_grant_query_size(current->domain, d);
@@ -2240,15 +2234,10 @@ gnttab_get_status_frames(XEN_GUEST_HANDL
return -EFAULT;
}
- rc = rcu_lock_target_domain_by_id(op.dom, &d);
- if ( rc < 0 )
+ d = gt_lock_target_domain_by_id(op.dom);
+ if ( IS_ERR(d) )
{
- if ( rc == -ESRCH )
- op.status = GNTST_bad_domain;
- else if ( rc == -EPERM )
- op.status = GNTST_permission_denied;
- else
- op.status = GNTST_general_error;
+ op.status = PTR_ERR(d);
goto out1;
}
rc = xsm_grant_setup(current->domain, d);
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -329,22 +329,9 @@ static long memory_exchange(XEN_GUEST_HA
out_chunk_order = exch.in.extent_order - exch.out.extent_order;
}
- if ( likely(exch.in.domid == DOMID_SELF) )
- {
- d = rcu_lock_current_domain();
- }
- else
- {
- if ( (d = rcu_lock_domain_by_id(exch.in.domid)) == NULL )
- goto fail_early;
-
- if ( !IS_PRIV_FOR(current->domain, d) )
- {
- rcu_unlock_domain(d);
- rc = -EPERM;
- goto fail_early;
- }
- }
+ rc = rcu_lock_target_domain_by_id(exch.in.domid, &d);
+ if ( rc )
+ goto fail_early;
memflags |= MEMF_bits(domain_clamp_alloc_bitsize(
d,
@@ -583,20 +570,8 @@ long do_memory_op(unsigned long cmd, XEN
&& (reservation.mem_flags & XENMEMF_populate_on_demand) )
args.memflags |= MEMF_populate_on_demand;
- if ( likely(reservation.domid == DOMID_SELF) )
- {
- d = rcu_lock_current_domain();
- }
- else
- {
- if ( (d = rcu_lock_domain_by_id(reservation.domid)) == NULL )
- return start_extent;
- if ( !IS_PRIV_FOR(current->domain, d) )
- {
- rcu_unlock_domain(d);
- return start_extent;
- }
- }
+ if ( unlikely(rcu_lock_target_domain_by_id(reservation.domid, &d)) )
+ return start_extent;
args.domain = d;
rc = xsm_memory_adjust_reservation(current->domain, d);
[-- Attachment #3: Type: text/plain, Size: 126 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] adjust a few RCU domain locking calls
2012-09-07 12:56 [PATCH] adjust a few RCU domain locking calls Jan Beulich
@ 2012-09-07 14:47 ` Keir Fraser
0 siblings, 0 replies; 2+ messages in thread
From: Keir Fraser @ 2012-09-07 14:47 UTC (permalink / raw)
To: Jan Beulich, xen-devel
On 07/09/2012 13:56, "Jan Beulich" <JBeulich@suse.com> wrote:
> x86's do_physdev_op() had a case where the locking was entirely
> superfluous. Its physdev_map_pirq() further had a case where the lock
> was being obtained too early, needlessly complicating early exit paths.
>
> Grant table code had two open coded instances of
> rcu_lock_target_domain_by_id(), and a third code section could be
> consolidated by using the newly introduced helper function.
>
> The memory hypercall code had two more instances of open coding
> rcu_lock_target_domain_by_id(), but note that here this is not just
> cleanup, but also fixes an error return path in memory_exchange() to
> actually return an error.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
> --- a/xen/arch/x86/physdev.c
> +++ b/xen/arch/x86/physdev.c
> @@ -90,14 +90,10 @@ static int physdev_hvm_map_pirq(
> int physdev_map_pirq(domid_t domid, int type, int *index, int *pirq_p,
> struct msi_info *msi)
> {
> - struct domain *d;
> + struct domain *d = current->domain;
> int pirq, irq, ret = 0;
> void *map_data = NULL;
>
> - ret = rcu_lock_target_domain_by_id(domid, &d);
> - if ( ret )
> - return ret;
> -
> if ( domid == DOMID_SELF && is_hvm_domain(d) )
> {
> /*
> @@ -105,14 +101,15 @@ int physdev_map_pirq(domid_t domid, int
> * calls back into itself and deadlocks on hvm_domain.irq_lock.
> */
> if ( !is_hvm_pv_evtchn_domain(d) )
> - {
> - ret = -EINVAL;
> - goto free_domain;
> - }
> - ret = physdev_hvm_map_pirq(d, type, index, pirq_p);
> - goto free_domain;
> + return -EINVAL;
> +
> + return physdev_hvm_map_pirq(d, type, index, pirq_p);
> }
>
> + ret = rcu_lock_target_domain_by_id(domid, &d);
> + if ( ret )
> + return ret;
> +
> if ( !IS_PRIV_FOR(current->domain, d) )
> {
> ret = -EPERM;
> @@ -696,13 +693,12 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
> }
> case PHYSDEVOP_get_free_pirq: {
> struct physdev_get_free_pirq out;
> - struct domain *d;
> + struct domain *d = v->domain;
>
> ret = -EFAULT;
> if ( copy_from_guest(&out, arg, 1) != 0 )
> break;
>
> - d = rcu_lock_current_domain();
> spin_lock(&d->event_lock);
>
> ret = get_free_pirq(d, out.type);
> @@ -717,7 +713,6 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
> }
>
> spin_unlock(&d->event_lock);
> - rcu_unlock_domain(d);
>
> if ( ret >= 0 )
> {
> --- a/xen/common/grant_table.c
> +++ b/xen/common/grant_table.c
> @@ -24,7 +24,7 @@
> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> */
>
> -#include <xen/config.h>
> +#include <xen/err.h>
> #include <xen/iocap.h>
> #include <xen/lib.h>
> #include <xen/sched.h>
> @@ -195,6 +195,30 @@ double_gt_unlock(struct grant_table *lgt
> spin_unlock(&rgt->lock);
> }
>
> +static struct domain *gt_lock_target_domain_by_id(domid_t dom)
> +{
> + struct domain *d;
> + int rc = GNTST_general_error;
> +
> + switch ( rcu_lock_target_domain_by_id(dom, &d) )
> + {
> + case 0:
> + return d;
> +
> + case -ESRCH:
> + gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
> + rc = GNTST_bad_domain;
> + break;
> +
> + case -EPERM:
> + rc = GNTST_permission_denied;
> + break;
> + }
> +
> + ASSERT(rc < 0 && -rc <= MAX_ERRNO);
> + return ERR_PTR(rc);
> +}
> +
> static inline int
> __get_maptrack_handle(
> struct grant_table *t)
> @@ -1261,7 +1285,6 @@ gnttab_setup_table(
> struct grant_table *gt;
> int i;
> unsigned long gmfn;
> - domid_t dom;
>
> if ( count != 1 )
> return -EINVAL;
> @@ -1281,25 +1304,11 @@ gnttab_setup_table(
> goto out1;
> }
>
> - dom = op.dom;
> - if ( dom == DOMID_SELF )
> + d = gt_lock_target_domain_by_id(op.dom);
> + if ( IS_ERR(d) )
> {
> - d = rcu_lock_current_domain();
> - }
> - else
> - {
> - if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
> - {
> - gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
> - op.status = GNTST_bad_domain;
> - goto out1;
> - }
> -
> - if ( unlikely(!IS_PRIV_FOR(current->domain, d)) )
> - {
> - op.status = GNTST_permission_denied;
> - goto out2;
> - }
> + op.status = PTR_ERR(d);
> + goto out1;
> }
>
> if ( xsm_grant_setup(current->domain, d) )
> @@ -1352,7 +1361,6 @@ gnttab_query_size(
> {
> struct gnttab_query_size op;
> struct domain *d;
> - domid_t dom;
> int rc;
>
> if ( count != 1 )
> @@ -1364,25 +1372,11 @@ gnttab_query_size(
> return -EFAULT;
> }
>
> - dom = op.dom;
> - if ( dom == DOMID_SELF )
> - {
> - d = rcu_lock_current_domain();
> - }
> - else
> + d = gt_lock_target_domain_by_id(op.dom);
> + if ( IS_ERR(d) )
> {
> - if ( unlikely((d = rcu_lock_domain_by_id(dom)) == NULL) )
> - {
> - gdprintk(XENLOG_INFO, "Bad domid %d.\n", dom);
> - op.status = GNTST_bad_domain;
> - goto query_out;
> - }
> -
> - if ( unlikely(!IS_PRIV_FOR(current->domain, d)) )
> - {
> - op.status = GNTST_permission_denied;
> - goto query_out_unlock;
> - }
> + op.status = PTR_ERR(d);
> + goto query_out;
> }
>
> rc = xsm_grant_query_size(current->domain, d);
> @@ -2240,15 +2234,10 @@ gnttab_get_status_frames(XEN_GUEST_HANDL
> return -EFAULT;
> }
>
> - rc = rcu_lock_target_domain_by_id(op.dom, &d);
> - if ( rc < 0 )
> + d = gt_lock_target_domain_by_id(op.dom);
> + if ( IS_ERR(d) )
> {
> - if ( rc == -ESRCH )
> - op.status = GNTST_bad_domain;
> - else if ( rc == -EPERM )
> - op.status = GNTST_permission_denied;
> - else
> - op.status = GNTST_general_error;
> + op.status = PTR_ERR(d);
> goto out1;
> }
> rc = xsm_grant_setup(current->domain, d);
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -329,22 +329,9 @@ static long memory_exchange(XEN_GUEST_HA
> out_chunk_order = exch.in.extent_order - exch.out.extent_order;
> }
>
> - if ( likely(exch.in.domid == DOMID_SELF) )
> - {
> - d = rcu_lock_current_domain();
> - }
> - else
> - {
> - if ( (d = rcu_lock_domain_by_id(exch.in.domid)) == NULL )
> - goto fail_early;
> -
> - if ( !IS_PRIV_FOR(current->domain, d) )
> - {
> - rcu_unlock_domain(d);
> - rc = -EPERM;
> - goto fail_early;
> - }
> - }
> + rc = rcu_lock_target_domain_by_id(exch.in.domid, &d);
> + if ( rc )
> + goto fail_early;
>
> memflags |= MEMF_bits(domain_clamp_alloc_bitsize(
> d,
> @@ -583,20 +570,8 @@ long do_memory_op(unsigned long cmd, XEN
> && (reservation.mem_flags & XENMEMF_populate_on_demand) )
> args.memflags |= MEMF_populate_on_demand;
>
> - if ( likely(reservation.domid == DOMID_SELF) )
> - {
> - d = rcu_lock_current_domain();
> - }
> - else
> - {
> - if ( (d = rcu_lock_domain_by_id(reservation.domid)) == NULL )
> - return start_extent;
> - if ( !IS_PRIV_FOR(current->domain, d) )
> - {
> - rcu_unlock_domain(d);
> - return start_extent;
> - }
> - }
> + if ( unlikely(rcu_lock_target_domain_by_id(reservation.domid, &d)) )
> + return start_extent;
> args.domain = d;
>
> rc = xsm_memory_adjust_reservation(current->domain, d);
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2012-09-07 14:47 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-09-07 12:56 [PATCH] adjust a few RCU domain locking calls Jan Beulich
2012-09-07 14:47 ` Keir Fraser
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).