From: Alexander Graf Date: Wed, 14 Jan 2015 01:32:11 +0100 Subject: AIO: Reduce number of threads for 32bit hosts On hosts with limited virtual address space (32bit pointers), we can very easily run out of virtual memory with big thread pools. Instead, we should limit ourselves to small pools to keep memory footprint low on those systems. This patch fixes random VM stalls like (process:25114): GLib-ERROR **: gmem.c:103: failed to allocate 1048576 bytes on 32bit ARM systems for me. Signed-off-by: Alexander Graf --- util/thread-pool.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/util/thread-pool.c b/util/thread-pool.c index 4ed9b89ab2d9c4e6d805ea47c2b2..697c989885ca8aa4dd1185b780df 100644 --- a/util/thread-pool.c +++ b/util/thread-pool.c @@ -307,7 +307,12 @@ static void thread_pool_init_one(ThreadPool *pool, AioContext *ctx) qemu_mutex_init(&pool->lock); qemu_cond_init(&pool->worker_stopped); qemu_sem_init(&pool->sem, 0); - pool->max_threads = 64; + if (sizeof(pool) == 4) { + /* 32bit systems run out of virtual memory quickly */ + pool->max_threads = 4; + } else { + pool->max_threads = 64; + } pool->new_thread_bh = aio_bh_new(ctx, spawn_thread_bh_fn, pool); QLIST_INIT(&pool->head);