Commit 911af505 introduced a bootmem warning.
From: Robin Holt
Date: Wed May 15 2013 - 03:57:49 EST
Paul,
When we boot Linus' current kernel we get the following warning early
in boot:
----------------------------------------------------------------------
[ 0.000000] Memory: 63081268k/99598336k available (4832k kernel code, 34651396k absent, 1865672k reserved, 6269k data,
1672k init)
[ 0.000000] Hierarchical RCU implementation.
[ 0.000000] RCU dyntick-idle grace-period acceleration is enabled.
[ 0.000000] RCU restricting CPUs from NR_CPUS=4096 to nr_cpu_ids=32.
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: at mm/nobootmem.c:215 ___alloc_bootmem_nopanic+0x79/0x82()
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-rc1-uv-hz100-rja+ #3
[ 0.000000] Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
[ 0.000000] 00000000000000d7 ffffffff81a01e38 ffffffff814a873c ffffffff81a01e78
[ 0.000000] ffffffff81045a7b ffffffff81ced5a2 0000000000000000 ffffffffffffffff
[ 0.000000] 0000000000000040 0000000000000200 0000000067da2bfc ffffffff81a01e88
[ 0.000000] Call Trace:
[ 0.000000] [<ffffffff814a873c>] dump_stack+0x19/0x1d
[ 0.000000] [<ffffffff81045a7b>] warn_slowpath_common+0x6b/0xa0
[ 0.000000] [<ffffffff81045ac5>] warn_slowpath_null+0x15/0x20
[ 0.000000] [<ffffffff81b1793a>] ___alloc_bootmem_nopanic+0x79/0x82
[ 0.000000] [<ffffffff81b17a59>] ___alloc_bootmem+0x11/0x3c
[ 0.000000] [<ffffffff81b17aa4>] __alloc_bootmem+0x10/0x12
[ 0.000000] [<ffffffff81b233a7>] alloc_bootmem_cpumask_var+0x1d/0x27
[ 0.000000] [<ffffffff81b1119b>] rcu_bootup_announce_oddness+0xd0/0x153
[ 0.000000] [<ffffffff81b11735>] rcu_init+0x1e/0x1e6
[ 0.000000] [<ffffffff81aedf2f>] start_kernel+0x1e6/0x43c
[ 0.000000] [<ffffffff81aedb3b>] ? repair_env_string+0x58/0x58
[ 0.000000] [<ffffffff81aed4d1>] x86_64_start_reservations+0x1b/0x32
[ 0.000000] [<ffffffff81aed612>] x86_64_start_kernel+0x12a/0x131
[ 0.000000] ---[ end trace c8b13488e92fad65 ]---
[ 0.000000] Experimental no-CBs for all CPUs
[ 0.000000] Experimental no-CBs CPUs: 0-31.
[ 0.000000] NO_HZ: Full dynticks CPUs: 1-31.
$ grep RCU .config
# RCU Subsystem
CONFIG_TREE_RCU=y
# CONFIG_PREEMPT_RCU is not set
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_USER_QS=y
CONFIG_RCU_FANOUT=64
CONFIG_RCU_FANOUT_LEAF=16
# CONFIG_RCU_FANOUT_EXACT is not set
CONFIG_RCU_FAST_NO_HZ=y
# CONFIG_TREE_RCU_TRACE is not set
CONFIG_RCU_NOCB_CPU=y
CONFIG_RCU_NOCB_CPU_ALL=y
# RCU Debugging
# CONFIG_SPARSE_RCU_POINTER is not set
# CONFIG_RCU_TORTURE_TEST is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=60
# CONFIG_RCU_CPU_STALL_INFO is not set
# CONFIG_RCU_TRACE is not set
$ git rev-parse HEAD
1f638766ffcd9f08209afcabb3e2df961552fe18
cca6f3931 (Paul E. McKenney 2012-05-08 21:00:28 -0700 86) if (nr_cpu_ids != NR_CPUS)
cca6f3931 (Paul E. McKenney 2012-05-08 21:00:28 -0700 87) printk(KERN_INFO "\tRCU restricting CPUs from NR_C
PUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids);
3fbfbf7a3 (Paul E. McKenney 2012-08-19 21:35:53 -0700 88) #ifdef CONFIG_RCU_NOCB_CPU
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 89) #ifndef CONFIG_RCU_NOCB_CPU_NONE
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 90) if (!have_rcu_nocb_mask) {
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 91) alloc_bootmem_cpumask_var(&rcu_nocb_mask);
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 92) have_rcu_nocb_mask = true;
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 93) }
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 94) #ifdef CONFIG_RCU_NOCB_CPU_ZERO
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 95) pr_info("\tExperimental no-CBs CPU 0\n");
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 96) cpumask_set_cpu(0, rcu_nocb_mask);
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 97) #endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 98) #ifdef CONFIG_RCU_NOCB_CPU_ALL
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 99) pr_info("\tExperimental no-CBs for all CPUs\n");
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 100) cpumask_setall(rcu_nocb_mask);
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 101) #endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */
911af505e (Paul E. McKenney 2013-02-11 10:23:27 -0800 102) #endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */
Thanks,
Robin Holt
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