diff options
Diffstat (limited to 'util/oslib-posix.c')
| -rw-r--r-- | util/oslib-posix.c | 131 |
1 files changed, 100 insertions, 31 deletions
diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 7c297003b9..3c379f96c2 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -42,6 +42,7 @@ #include "qemu/cutils.h" #include "qemu/units.h" #include "qemu/thread-context.h" +#include "qemu/main-loop.h" #ifdef CONFIG_LINUX #include <sys/syscall.h> @@ -63,11 +64,15 @@ 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 { @@ -412,19 +417,44 @@ static inline int get_memset_num_threads(size_t hpagesize, size_t numpages, return ret; } +static int wait_and_free_mem_prealloc_context(MemsetContext *context) +{ + int i, ret = 0, tmp; + + for (i = 0; i < context->num_threads; i++) { + tmp = (uintptr_t)qemu_thread_join(&context->threads[i].pgthread); + + if (tmp) { + ret = tmp; + } + } + g_free(context->threads); + g_free(context); + return ret; +} + static int touch_all_pages(char *area, size_t hpagesize, size_t numpages, - int max_threads, ThreadContext *tc, + int max_threads, ThreadContext *tc, bool async, 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 ret, i = 0; char *addr = area; + /* + * Asynchronous preallocation is only allowed when using MADV_POPULATE_WRITE + * and prealloc context for thread placement. + */ + if (!use_madv_populate_write || !tc) { + async = false; + } + + 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); @@ -432,8 +462,11 @@ 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) { + /* + * Avoid creating a single thread for MADV_POPULATE_WRITE when + * preallocating synchronously. + */ + if (context->num_threads == 1 && !async) { if (qemu_madvise(area, hpagesize * numpages, QEMU_MADV_POPULATE_WRITE)) { return -errno; @@ -445,50 +478,86 @@ 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; + } + + if (async) { + /* + * async requests currently require the BQL. Add it to the list and kick + * preallocation off during qemu_finish_async_prealloc_mem(). + */ + assert(bql_locked()); + QLIST_INSERT_HEAD(&memset_contexts, context, next); + return 0; } if (!use_madv_populate_write) { - sigbus_memset_context = &context; + sigbus_memset_context = context; } qemu_mutex_lock(&page_mutex); - context.all_threads_created = true; + 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); + ret = wait_and_free_mem_prealloc_context(context); + if (!use_madv_populate_write) { + sigbus_memset_context = NULL; + } + return ret; +} + +bool qemu_finish_async_prealloc_mem(Error **errp) +{ + int ret = 0, tmp; + MemsetContext *context, *next_context; + + /* Waiting for preallocation requires the BQL. */ + assert(bql_locked()); + if (QLIST_EMPTY(&memset_contexts)) { + return true; + } + + qemu_mutex_lock(&page_mutex); + QLIST_FOREACH(context, &memset_contexts, next) { + context->all_threads_created = true; + } + qemu_cond_broadcast(&page_cond); + qemu_mutex_unlock(&page_mutex); + + QLIST_FOREACH_SAFE(context, &memset_contexts, next, next_context) { + QLIST_REMOVE(context, next); + tmp = wait_and_free_mem_prealloc_context(context); if (tmp) { ret = tmp; } } - if (!use_madv_populate_write) { - sigbus_memset_context = NULL; + if (ret) { + error_setg_errno(errp, -ret, + "qemu_prealloc_mem: preallocating memory failed"); + return false; } - g_free(context.threads); - - return ret; + return true; } static bool madv_populate_write_possible(char *area, size_t pagesize) @@ -498,7 +567,7 @@ static bool madv_populate_write_possible(char *area, size_t pagesize) } bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, - ThreadContext *tc, Error **errp) + ThreadContext *tc, bool async, Error **errp) { static gsize initialized; int ret; @@ -540,7 +609,7 @@ bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, } /* touch pages simultaneously */ - ret = touch_all_pages(area, hpagesize, numpages, max_threads, tc, + ret = touch_all_pages(area, hpagesize, numpages, max_threads, tc, async, use_madv_populate_write); if (ret) { error_setg_errno(errp, -ret, |