File 0014-AIO-Reduce-number-of-threads-for-32.patch of Package qemu

Overview Repositories Revisions Requests Users Attributes Meta

File 0014-AIO-Reduce-number-of-threads-for-32.patch of Package qemu (Revision 0333c837007b9797db4f85403e322be2)

Currently displaying revision 0333c837007b9797db4f85403e322be2 , Show latest

From c82a9a0340bc03bc4aa4fe1cf2d667617371f558 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Wed, 14 Jan 2015 01:32:11 +0100
Subject: [PATCH] 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 <agraf@suse.de>
---
 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 610646d131..2e34e9846d 100644
--- a/util/thread-pool.c
+++ b/util/thread-pool.c
@@ -308,7 +308,12 @@ 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);

Places

File 0014-AIO-Reduce-number-of-threads-for-32.patch of Package qemu (Revision 0333c837007b9797db4f85403e322be2)

Places