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

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File 0014-AIO-Reduce-number-of-threads-for-32.patch of Package qemu (Revision 52b49f754e5d32d08da8baeea29762c2)

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From f15645e3c37bbb274a4c0edbbec9cac7386ec660 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);

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File 0014-AIO-Reduce-number-of-threads-for-32.patch of Package qemu (Revision 52b49f754e5d32d08da8baeea29762c2)

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