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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH RFC 44/59] libxl: Implement CpupoolCreate
From: George Dunlap <george.dunlap@xxxxxxxxxx>
Implement CpupoolCreate.
For now, follow the lead of "xl cpupool-create", by automatically
generating a new uuid each time a new cpupool is created, and by not
allowing the user to attempt to set the poolid.
This requires us to implement bytmapGotoC, which C-allocates the
appropriate array and copies the Go byte map into it. This must be
C-allocated because the runtime restricts how Go-allocated structures
can be passed into C function calls.
While we're here, reorganize functions slightly, and change the Bitmap
implementation to automatically extend the array if the size of the
byte array is too small.
Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxx>
---
libxl.go | 119 +++++++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 85 insertions(+), 34 deletions(-)
diff --git a/libxl.go b/libxl.go
index 3f6ba01..6e17b53 100644
--- a/libxl.go
+++ b/libxl.go
@@ -176,20 +176,38 @@ func (bm *Bitmap) Alloc(max int) {
}
// Return a Go bitmap which is a copy of the referred C bitmap.
-func bitmapCToGo(cbm *C.libxl_bitmap) (bm Bitmap) {
+func bitmapCToGo(cbm *C.libxl_bitmap) (gbm Bitmap) {
// Alloc a Go slice for the bytes
size := int(cbm.size)
- bm.Alloc(size*8)
+ gbm.Alloc(size*8)
// Make a slice pointing to the C array
mapslice := (*[1 << 30]C.uint8_t)(unsafe.Pointer(cbm._map))[:size:size]
// And copy the C array into the Go array
- copy(bm.bitmap, mapslice)
+ copy(gbm.bitmap, mapslice)
return
}
+// Must be C.libxl_bitmap_dispose'd of afterwards
+func bitmapGotoC(gbm Bitmap, cbm *C.libxl_bitmap) {
+ C.libxl_bitmap_init(cbm)
+
+ size := len(gbm.bitmap)
+ cbm._map = (*C.uint8_t)(C.malloc(C.size_t(size)))
+ cbm.size = C.uint32_t(size)
+ if cbm._map == nil {
+ panic("C.calloc failed!")
+ }
+
+ // Make a slice pointing to the C array
+ mapslice := (*[1 << 30]C.uint8_t)(unsafe.Pointer(cbm._map))[:size:size]
+
+ // And copy the Go array into the C array
+ copy(mapslice, gbm.bitmap)
+}
+
func (bm *Bitmap) Test(bit int) (bool) {
ubit := uint(bit)
if (bit > bm.Max()) {
@@ -199,14 +217,13 @@ func (bm *Bitmap) Test(bit int) (bool) {
return (bm.bitmap[bit / 8] & (1 << (ubit & 7))) != 0
}
-// FIXME: Do we really just want to silently fail here?
func (bm *Bitmap) Set(bit int) {
- ubit := uint(bit)
- if (bit > bm.Max()) {
- return
+ ibit := bit / 8;
+ if (ibit + 1 > len(bm.bitmap)) {
+ bm.bitmap = append(bm.bitmap, make([]C.uint8_t,
ibit+1-len(bm.bitmap))...)
}
- bm.bitmap[bit / 8] |= 1 << (ubit & 7)
+ bm.bitmap[ibit] |= 1 << (uint(bit) & 7)
}
func (bm *Bitmap) Clear(bit int) {
@@ -234,12 +251,12 @@ func (bm *Bitmap) Max() (int) {
// ])
type Scheduler int
var (
- SchedulerUnknown Scheduler = 0
- SchedulerSedf Scheduler = 4
- SchedulerCredit Scheduler = 5
- SchedulerCredit2 Scheduler = 6
- SchedulerArinc653 Scheduler = 7
- SchedulerRTDS Scheduler = 8
+ SchedulerUnknown Scheduler = C.LIBXL_SCHEDULER_UNKNOWN
+ SchedulerSedf Scheduler = C.LIBXL_SCHEDULER_SEDF
+ SchedulerCredit Scheduler = C.LIBXL_SCHEDULER_CREDIT
+ SchedulerCredit2 Scheduler = C.LIBXL_SCHEDULER_CREDIT2
+ SchedulerArinc653 Scheduler = C.LIBXL_SCHEDULER_ARINC653
+ SchedulerRTDS Scheduler = C.LIBXL_SCHEDULER_RTDS
)
// const char *libxl_scheduler_to_string(libxl_scheduler p);
@@ -315,23 +332,38 @@ func (Ctx *Context) ListCpupool() (list []CpupoolInfo) {
return
}
-func (Ctx *Context) CpupoolFindByName(name string) (info CpupoolInfo, found
bool) {
- plist := Ctx.ListCpupool()
+// int libxl_cpupool_create(libxl_ctx *ctx, const char *name,
+// libxl_scheduler sched,
+// libxl_bitmap cpumap, libxl_uuid *uuid,
+// uint32_t *poolid);
+// FIXME: uuid
+// FIXME: Setting poolid
+func (Ctx *Context) CpupoolCreate(Name string, Scheduler Scheduler, Cpumap
Bitmap) (err error, Poolid uint32) {
+ poolid := C.uint32_t(0)
+ name := C.CString(Name)
+ defer C.free(unsafe.Pointer(name))
+
+ // For now, just do what xl does, and make a new uuid every time we
create the pool
+ var uuid C.libxl_uuid
+ C.libxl_uuid_generate(&uuid)
- for i := range plist {
- if plist[i].PoolName == name {
- found = true
- info = plist[i]
- return
- }
+ var cbm C.libxl_bitmap
+ bitmapGotoC(Cpumap, &cbm)
+ defer C.libxl_bitmap_dispose(&cbm)
+
+ ret := C.libxl_cpupool_create(Ctx.ctx, name,
C.libxl_scheduler(Scheduler),
+ cbm, &uuid, &poolid)
+ // FIXME: Proper error
+ if ret != 0 {
+ err = fmt.Errorf("libxl_cpupool_create failed: %d", ret)
+ return
}
+
+ Poolid = uint32(poolid)
+
return
}
-// int libxl_cpupool_create(libxl_ctx *ctx, const char *name,
-// libxl_scheduler sched,
-// libxl_bitmap cpumap, libxl_uuid *uuid,
-// uint32_t *poolid);
// int libxl_cpupool_destroy(libxl_ctx *ctx, uint32_t poolid);
// int libxl_cpupool_rename(libxl_ctx *ctx, const char *name, uint32_t poolid);
// int libxl_cpupool_cpuadd(libxl_ctx *ctx, uint32_t poolid, int cpu);
@@ -345,7 +377,22 @@ func (Ctx *Context) CpupoolFindByName(name string) (info
CpupoolInfo, found bool
// int libxl_cpupool_movedomain(libxl_ctx *ctx, uint32_t poolid, uint32_t
domid);
// int libxl_cpupool_info(libxl_ctx *ctx, libxl_cpupoolinfo *info, uint32_t
poolid);
-
+//
+// Utility functions
+//
+func (Ctx *Context) CpupoolFindByName(name string) (info CpupoolInfo, found
bool) {
+ plist := Ctx.ListCpupool()
+
+ for i := range plist {
+ if plist[i].PoolName == name {
+ found = true
+ info = plist[i]
+ return
+ }
+ }
+ return
+}
+
func XlTest(Args []string) {
var Ctx Context
@@ -384,15 +431,19 @@ func XlTest(Args []string) {
}
fmt.Printf("\n")
} else {
- fmt.Printf("schedbench not found")
- }
+ fmt.Printf("schedbench not found, creating\n")
- pool, found = Ctx.CpupoolFindByName("schedbnch")
+ var Cpumap Bitmap
+ var Poolid uint32
- if found {
- fmt.Printf("%v\n", pool)
- } else {
- fmt.Printf("schedbnch not found\n")
+ Cpumap.Set(15)
+
+ err, Poolid = Ctx.CpupoolCreate("schedbench", SchedulerCredit,
Cpumap)
+ if err != nil {
+ fmt.Printf("Error creating cpupool: %v\n", err)
+ } else {
+ fmt.Printf("Pool id: %d\n", Poolid)
+ }
}
Ctx.Close()
--
2.7.4
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