Retpolines are expensive, and all these do are select between the sync and
nosync helpers. Pass a boolean instead, and use direct calls everywhere.
Pause/unpause operations on behalf of dom0 are not fastpaths, so avoid
exposing the __domain_pause_by_systemcontroller() internal.
This actually compiles smaller than before:
$ ../scripts/bloat-o-meter xen-syms-before xen-syms-after
add/remove: 3/1 grow/shrink: 0/5 up/down: 250/-273 (-23)
Function old new delta
_domain_pause - 115 +115
domain_pause_by_systemcontroller - 69 +69
domain_pause_by_systemcontroller_nosync - 66 +66
domain_kill 426 398 -28
domain_resume 246 214 -32
domain_pause_except_self 189 141 -48
domain_pause 59 10 -49
domain_pause_nosync 59 7 -52
__domain_pause_by_systemcontroller 64 - -64
despite GCC's best efforts. The new _domain_pause_by_systemcontroller()
really should not be inlined, considering that the difference is only the
setup of the sync boolean to pass to _domain_pause(), and there are plenty of
registers to spare.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Roger Pau Monné <roger....@citrix.com>
CC: Wei Liu <w...@xen.org>
CC: Stefano Stabellini <sstabell...@kernel.org>
CC: Julien Grall <jul...@xen.org>
CC: Volodymyr Babchuk <volodymyr_babc...@epam.com>
CC: Bertrand Marquis <bertrand.marq...@arm.com>
---
xen/common/domain.c | 31 ++++++++++++++++++++++---------
xen/include/xen/sched.h | 15 +++++----------
2 files changed, 27 insertions(+), 19 deletions(-)
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 56d47dd66478..562872cdf87a 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1234,15 +1234,18 @@ int vcpu_unpause_by_systemcontroller(struct vcpu *v)
return 0;
}
-static void do_domain_pause(struct domain *d,
- void (*sleep_fn)(struct vcpu *v))
+static void _domain_pause(struct domain *d, bool sync /* or nosync */)
{
struct vcpu *v;
atomic_inc(&d->pause_count);
- for_each_vcpu( d, v )
- sleep_fn(v);
+ if ( sync )
+ for_each_vcpu ( d, v )
+ vcpu_sleep_sync(v);
+ else
+ for_each_vcpu ( d, v )
+ vcpu_sleep_nosync(v);
arch_domain_pause(d);
}
@@ -1250,12 +1253,12 @@ static void do_domain_pause(struct domain *d,
void domain_pause(struct domain *d)
{
ASSERT(d != current->domain);
- do_domain_pause(d, vcpu_sleep_sync);
+ _domain_pause(d, true /* sync */);
}
void domain_pause_nosync(struct domain *d)
{
- do_domain_pause(d, vcpu_sleep_nosync);
+ _domain_pause(d, false /* nosync */);
}
void domain_unpause(struct domain *d)
@@ -1269,8 +1272,8 @@ void domain_unpause(struct domain *d)
vcpu_wake(v);
}
-int __domain_pause_by_systemcontroller(struct domain *d,
- void (*pause_fn)(struct domain *d))
+static int _domain_pause_by_systemcontroller(
+ struct domain *d, bool sync /* or nosync */)
{
int old, new, prev = d->controller_pause_count;
@@ -1289,11 +1292,21 @@ int __domain_pause_by_systemcontroller(struct domain *d,
prev = cmpxchg(&d->controller_pause_count, old, new);
} while ( prev != old );
- pause_fn(d);
+ _domain_pause(d, sync);
return 0;
}
+int domain_pause_by_systemcontroller(struct domain *d)
+{
+ return _domain_pause_by_systemcontroller(d, true /* sync */);
+}
+
+int domain_pause_by_systemcontroller_nosync(struct domain *d)
+{
+ return _domain_pause_by_systemcontroller(d, false /* nosync */);
+}
+
int domain_unpause_by_systemcontroller(struct domain *d)
{
int old, new, prev = d->controller_pause_count;
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 28146ee404e6..37f78cc4c4c9 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -920,26 +920,21 @@ static inline bool vcpu_cpu_dirty(const struct vcpu *v)
void vcpu_block(void);
void vcpu_unblock(struct vcpu *v);
+
void vcpu_pause(struct vcpu *v);
void vcpu_pause_nosync(struct vcpu *v);
void vcpu_unpause(struct vcpu *v);
+
int vcpu_pause_by_systemcontroller(struct vcpu *v);
int vcpu_unpause_by_systemcontroller(struct vcpu *v);
void domain_pause(struct domain *d);
void domain_pause_nosync(struct domain *d);
void domain_unpause(struct domain *d);
+
+int domain_pause_by_systemcontroller(struct domain *d);
+int domain_pause_by_systemcontroller_nosync(struct domain *d);
int domain_unpause_by_systemcontroller(struct domain *d);
-int __domain_pause_by_systemcontroller(struct domain *d,
- void (*pause_fn)(struct domain *d));
-static inline int domain_pause_by_systemcontroller(struct domain *d)
-{
- return __domain_pause_by_systemcontroller(d, domain_pause);
-}
-static inline int domain_pause_by_systemcontroller_nosync(struct domain *d)
-{
- return __domain_pause_by_systemcontroller(d, domain_pause_nosync);
-}
/* domain_pause() but safe against trying to pause current. */
int __must_check domain_pause_except_self(struct domain *d);
--
2.11.0
