On Wed, Aug 8, 2012 at 5:35 PM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > Il 08/08/2012 08:25, Liu Ping Fan ha scritto: >> From: Liu Ping Fan <pingfank@xxxxxxxxxxxxxxxxxx> >> >> Collect unused object and release them at caller demand. >> >> Signed-off-by: Liu Ping Fan <pingfank@xxxxxxxxxxxxxxxxxx> >> --- >> include/qemu/reclaimer.h | 28 ++++++++++++++++++++++ >> main-loop.c | 5 ++++ >> qemu-tool.c | 5 ++++ >> qom/Makefile.objs | 2 +- >> qom/reclaimer.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++ >> 5 files changed, 97 insertions(+), 1 deletions(-) >> create mode 100644 include/qemu/reclaimer.h >> create mode 100644 qom/reclaimer.c >> >> diff --git a/include/qemu/reclaimer.h b/include/qemu/reclaimer.h >> new file mode 100644 >> index 0000000..9307e93 >> --- /dev/null >> +++ b/include/qemu/reclaimer.h >> @@ -0,0 +1,28 @@ >> +/* >> + * QEMU reclaimer >> + * >> + * Copyright IBM, Corp. 2012 >> + * >> + * This work is licensed under the terms of the GNU GPL, version 2 or later. >> + * See the COPYING file in the top-level directory. >> + */ >> + >> +#ifndef QEMU_RECLAIMER >> +#define QEMU_RECLAIMER >> + >> +typedef void ReleaseHandler(void *opaque); >> +typedef struct Chunk { >> + QLIST_ENTRY(Chunk) list; >> + void *opaque; >> + ReleaseHandler *release; >> +} Chunk; >> + >> +typedef struct ChunkHead { >> + struct Chunk *lh_first; >> +} ChunkHead; >> + >> +void reclaimer_enqueue(ChunkHead *head, void *opaque, ReleaseHandler *release); >> +void reclaimer_worker(ChunkHead *head); >> +void qemu_reclaimer_enqueue(void *opaque, ReleaseHandler *release); >> +void qemu_reclaimer(void); > > So "enqueue" is call_rcu and qemu_reclaimer marks a quiescent state + > empties the pending call_rcu. > > But what's the difference between the two pairs of APIs? > I add the new one for V2 to reclaim the resource for mem view. And yes, as you point out, I will delete the 2nd API, for it can be substituted by the 1st one easily. >> +#endif >> diff --git a/main-loop.c b/main-loop.c >> index eb3b6e6..be9d095 100644 >> --- a/main-loop.c >> +++ b/main-loop.c >> @@ -26,6 +26,7 @@ >> #include "qemu-timer.h" >> #include "slirp/slirp.h" >> #include "main-loop.h" >> +#include "qemu/reclaimer.h" >> >> #ifndef _WIN32 >> >> @@ -505,5 +506,9 @@ int main_loop_wait(int nonblocking) >> them. */ >> qemu_bh_poll(); >> >> + /* ref to device from iohandler/bh/timer do not obey the rules, so delay >> + * reclaiming until now. >> + */ >> + qemu_reclaimer(); >> return ret; >> } >> diff --git a/qemu-tool.c b/qemu-tool.c >> index 318c5fc..f5fe319 100644 >> --- a/qemu-tool.c >> +++ b/qemu-tool.c >> @@ -21,6 +21,7 @@ >> #include "main-loop.h" >> #include "qemu_socket.h" >> #include "slirp/libslirp.h" >> +#include "qemu/reclaimer.h" >> >> #include <sys/time.h> >> >> @@ -75,6 +76,10 @@ void qemu_mutex_unlock_iothread(void) >> { >> } >> >> +void qemu_reclaimer(void) >> +{ >> +} >> + >> int use_icount; >> >> void qemu_clock_warp(QEMUClock *clock) >> diff --git a/qom/Makefile.objs b/qom/Makefile.objs >> index 5ef060a..a579261 100644 >> --- a/qom/Makefile.objs >> +++ b/qom/Makefile.objs >> @@ -1,4 +1,4 @@ >> -qom-obj-y = object.o container.o qom-qobject.o >> +qom-obj-y = object.o container.o qom-qobject.o reclaimer.o >> qom-obj-twice-y = cpu.o >> common-obj-y = $(qom-obj-twice-y) >> user-obj-y = $(qom-obj-twice-y) >> diff --git a/qom/reclaimer.c b/qom/reclaimer.c >> new file mode 100644 >> index 0000000..6cb53e3 >> --- /dev/null >> +++ b/qom/reclaimer.c >> @@ -0,0 +1,58 @@ >> +/* >> + * QEMU reclaimer >> + * >> + * Copyright IBM, Corp. 2012 >> + * >> + * This work is licensed under the terms of the GNU GPL, version 2 or later. >> + * See the COPYING file in the top-level directory. >> + */ >> + >> +#include "qemu-common.h" >> +#include "qemu-thread.h" >> +#include "main-loop.h" >> +#include "qemu-queue.h" >> +#include "qemu/reclaimer.h" >> + >> +static struct QemuMutex reclaimer_lock; >> +static QLIST_HEAD(rcl, Chunk) reclaimer_list; >> + >> +void reclaimer_enqueue(ChunkHead *head, void *opaque, ReleaseHandler *release) >> +{ >> + Chunk *r = g_malloc0(sizeof(Chunk)); >> + r->opaque = opaque; >> + r->release = release; >> + QLIST_INSERT_HEAD_RCU(head, r, list); >> +} > > No lock? Yes, need! I will think it more closely. Thanks and regards, pingfan > >> +void reclaimer_worker(ChunkHead *head) >> +{ >> + Chunk *cur, *next; >> + >> + QLIST_FOREACH_SAFE(cur, head, list, next) { >> + QLIST_REMOVE(cur, list); >> + cur->release(cur->opaque); >> + g_free(cur); >> + } > > QLIST_REMOVE needs a lock too, so using the lockless > QLIST_INSERT_HEAD_RCU is not necessary. > >> +} >> + >> +void qemu_reclaimer_enqueue(void *opaque, ReleaseHandler *release) >> +{ >> + Chunk *r = g_malloc0(sizeof(Chunk)); >> + r->opaque = opaque; >> + r->release = release; >> + qemu_mutex_lock(&reclaimer_lock); >> + QLIST_INSERT_HEAD_RCU(&reclaimer_list, r, list); >> + qemu_mutex_unlock(&reclaimer_lock); >> +} >> + >> + >> +void qemu_reclaimer(void) >> +{ >> + Chunk *cur, *next; >> + >> + QLIST_FOREACH_SAFE(cur, &reclaimer_list, list, next) { >> + QLIST_REMOVE(cur, list); >> + cur->release(cur->opaque); >> + g_free(cur); >> + } > > Same here. > >> +} >> > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html