Refactor the memory prealloc threads support:
- Make memset context a global qlist
- Move the memset thread join/cleanup code to a separate routine
This is functionally equivalent and facilitates multiple memset contexts
(used in a subsequent patch).
Signed-off-by: Mark Kanda <mark.ka...@oracle.com>
---
util/oslib-posix.c | 104 +++++++++++++++++++++++++++++----------------
1 file changed, 68 insertions(+), 36 deletions(-)
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index e86fd64e09..293297ac6c 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -63,11 +63,15 @@
struct MemsetThread;
+static QLIST_HEAD(, MemsetContext) memset_contexts =
+ QLIST_HEAD_INITIALIZER(memset_contexts);
+
typedef struct MemsetContext {
bool all_threads_created;
bool any_thread_failed;
struct MemsetThread *threads;
int num_threads;
+ QLIST_ENTRY(MemsetContext) next;
} MemsetContext;
struct MemsetThread {
@@ -81,7 +85,7 @@ struct MemsetThread {
typedef struct MemsetThread MemsetThread;
/* used by sigbus_handler() */
-static MemsetContext *sigbus_memset_context;
+static bool sigbus_memset_context;
struct sigaction sigbus_oldact;
static QemuMutex sigbus_mutex;
@@ -295,13 +299,16 @@ static void sigbus_handler(int signal)
#endif /* CONFIG_LINUX */
{
int i;
+ MemsetContext *context;
if (sigbus_memset_context) {
- for (i = 0; i < sigbus_memset_context->num_threads; i++) {
- MemsetThread *thread = &sigbus_memset_context->threads[i];
+ QLIST_FOREACH(context, &memset_contexts, next) {
+ for (i = 0; i < context->num_threads; i++) {
+ MemsetThread *thread = &context->threads[i];
- if (qemu_thread_is_self(&thread->pgthread)) {
- siglongjmp(thread->env, 1);
+ if (qemu_thread_is_self(&thread->pgthread)) {
+ siglongjmp(thread->env, 1);
+ }
}
}
}
@@ -417,14 +424,15 @@ static int touch_all_pages(char *area, size_t hpagesize,
size_t numpages,
bool use_madv_populate_write)
{
static gsize initialized = 0;
- MemsetContext context = {
- .num_threads = get_memset_num_threads(hpagesize, numpages,
max_threads),
- };
+ MemsetContext *context = g_malloc0(sizeof(MemsetContext));
size_t numpages_per_thread, leftover;
void *(*touch_fn)(void *);
- int ret = 0, i = 0;
+ int i = 0;
char *addr = area;
+ context->num_threads =
+ get_memset_num_threads(hpagesize, numpages, max_threads);
+
if (g_once_init_enter(&initialized)) {
qemu_mutex_init(&page_mutex);
qemu_cond_init(&page_cond);
@@ -433,7 +441,7 @@ static int touch_all_pages(char *area, size_t hpagesize,
size_t numpages,
if (use_madv_populate_write) {
/* Avoid creating a single thread for MADV_POPULATE_WRITE */
- if (context.num_threads == 1) {
+ if (context->num_threads == 1) {
if (qemu_madvise(area, hpagesize * numpages,
QEMU_MADV_POPULATE_WRITE)) {
return -errno;
@@ -445,49 +453,74 @@ static int touch_all_pages(char *area, size_t hpagesize,
size_t numpages,
touch_fn = do_touch_pages;
}
- context.threads = g_new0(MemsetThread, context.num_threads);
- numpages_per_thread = numpages / context.num_threads;
- leftover = numpages % context.num_threads;
- for (i = 0; i < context.num_threads; i++) {
- context.threads[i].addr = addr;
- context.threads[i].numpages = numpages_per_thread + (i < leftover);
- context.threads[i].hpagesize = hpagesize;
- context.threads[i].context = &context;
+ context->threads = g_new0(MemsetThread, context->num_threads);
+ numpages_per_thread = numpages / context->num_threads;
+ leftover = numpages % context->num_threads;
+ for (i = 0; i < context->num_threads; i++) {
+ context->threads[i].addr = addr;
+ context->threads[i].numpages = numpages_per_thread + (i < leftover);
+ context->threads[i].hpagesize = hpagesize;
+ context->threads[i].context = context;
if (tc) {
- thread_context_create_thread(tc, &context.threads[i].pgthread,
+ thread_context_create_thread(tc, &context->threads[i].pgthread,
"touch_pages",
- touch_fn, &context.threads[i],
+ touch_fn, &context->threads[i],
QEMU_THREAD_JOINABLE);
} else {
- qemu_thread_create(&context.threads[i].pgthread, "touch_pages",
- touch_fn, &context.threads[i],
+ qemu_thread_create(&context->threads[i].pgthread, "touch_pages",
+ touch_fn, &context->threads[i],
QEMU_THREAD_JOINABLE);
}
- addr += context.threads[i].numpages * hpagesize;
+ addr += context->threads[i].numpages * hpagesize;
}
+ QLIST_INSERT_HEAD(&memset_contexts, context, next);
+
if (!use_madv_populate_write) {
- sigbus_memset_context = &context;
+ sigbus_memset_context = true;
}
+ return 0;
+}
+
+static int wait_mem_prealloc(void)
+{
+ int i, ret = 0;
+ MemsetContext *context, *next_context;
qemu_mutex_lock(&page_mutex);
- context.all_threads_created = true;
+ QLIST_FOREACH(context, &memset_contexts, next) {
+ context->all_threads_created = true;
+ }
qemu_cond_broadcast(&page_cond);
qemu_mutex_unlock(&page_mutex);
- for (i = 0; i < context.num_threads; i++) {
- int tmp = (uintptr_t)qemu_thread_join(&context.threads[i].pgthread);
+ QLIST_FOREACH(context, &memset_contexts, next) {
+ for (i = 0; i < context->num_threads; i++) {
+ int tmp =
+ (uintptr_t)qemu_thread_join(&context->threads[i].pgthread);
- if (tmp) {
- ret = tmp;
+ if (tmp) {
+ ret = tmp;
+ }
}
}
- if (!use_madv_populate_write) {
- sigbus_memset_context = NULL;
+ if (sigbus_oldact.sa_handler) {
+ /* restore the previous sighandler */
+ if (sigaction(SIGBUS, &sigbus_oldact, NULL)) {
+ /* Terminate QEMU since it can't recover from error */
+ perror("wait_mem_prealloc: failed to reinstall signal handler");
+ exit(1);
+ }
+ memset(&sigbus_oldact, 0, sizeof(sigbus_oldact));
}
- g_free(context.threads);
+ sigbus_memset_context = false;
+ QLIST_FOREACH_SAFE(context, &memset_contexts, next, next_context) {
+ QLIST_REMOVE(context, next);
+ g_free(context->threads);
+ g_free(context);
+ }
return ret;
}
@@ -547,11 +580,10 @@ void qemu_prealloc_mem(int fd, char *area, size_t sz, int
max_threads,
}
if (!use_madv_populate_write) {
- ret = sigaction(SIGBUS, &sigbus_oldact, NULL);
+ ret = wait_mem_prealloc();
if (ret) {
- /* Terminate QEMU since it can't recover from error */
- perror("qemu_prealloc_mem: failed to reinstall signal handler");
- exit(1);
+ error_setg_errno(errp, -ret,
+ "qemu_prealloc_mem: failed waiting for memory prealloc");
}
qemu_mutex_unlock(&sigbus_mutex);
}
--
2.39.3
