From f95ae4415ecbbb21d7095d4c6730be32c60182a0 Mon Sep 17 00:00:00 2001 From: Anders Roxell Date: Fri, 7 Dec 2018 10:17:47 +0100 Subject: [PATCH] dma-debug: fix soft lockup when a lot of debug are enabled When running a kernel in qemu with enough debugging options (slub-debug, ftrace, kcov, kasan, ubsan, ...) enabled together, that results in a slow initcall. So a 'watchdog: BUG: soft lockup' happens: [ 44.105619] Call trace: [ 44.106709] __slab_alloc+0x70/0x88 [ 44.107757] kmem_cache_alloc_trace+0x13c/0x590 [ 44.108764] prealloc_memory+0xb8/0x240 [ 44.109768] dma_debug_init+0x174/0x1f0 [ 44.110725] do_one_initcall+0x430/0x8b0 [ 44.111719] do_initcall_level+0x548/0x5b4 [ 44.112672] do_initcalls+0x28/0x4c [ 44.113628] do_basic_setup+0x34/0x3c [ 44.114559] kernel_init_freeable+0x194/0x24c [ 44.115570] kernel_init+0x24/0x18c [ 44.116498] ret_from_fork+0x10/0x18 Rework to call cond_resched(), in the function prealloc_memory()'s for-loop. Co-developed-by: Arnd Bergmann Signed-off-by: Arnd Bergmann Signed-off-by: Anders Roxell --- kernel/dma/debug.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 231ca4628062..2abdc265aec4 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -767,6 +767,7 @@ static int prealloc_memory(u32 num_entries) int i; for (i = 0; i < num_entries; ++i) { + cond_resched(); entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) goto out_err; -- 2.19.2