From: Peter Zijlstra <peterz@infradead.org>
To: Feng Tang <feng.tang@intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
"H . Peter Anvin" <hpa@linux.intel.com>,
Yinghai Lu <yinghai@kernel.org>,
Dave Hansen <dave.hansen@intel.com>,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH] x86, mm: Reserver some memory for bootmem allocator for NO_BOOTMEM
Date: Thu, 30 Aug 2018 12:44:02 +0200 [thread overview]
Message-ID: <20180830104401.GZ24124@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180830090319.985-1-feng.tang@intel.com>
On Thu, Aug 30, 2018 at 05:03:19PM +0800, Feng Tang wrote:
> We hit a kernel panic when enabling earlycon for a platform, the
> call trace is:
>
> panic+0xd2/0x220
> __alloc_bootmem+0x31/0x34
> spp_getpage+0x60/0x8a
> fill_pte+0x71/0x130
> __set_pte_vaddr+0x1d/0x50
> set_pte_vaddr+0x3c/0x60
> __native_set_fixmap+0x23/0x30
> native_set_fixmap+0x30/0x40
> setup_earlycon+0x1e0/0x32f
> param_setup_earlycon+0x13/0x22
> do_early_param+0x5b/0x90
> parse_args+0x1f7/0x300
> parse_early_options+0x24/0x28
> parse_early_param+0x65/0x73
> setup_arch+0x31e/0x9f1
> start_kernel+0x58/0x44e
>
> The root cause is that when CONFIG_NO_BOOTMEM=y, before
> e820__memblock_setup() is called there is no memory for bootmem
> to allocate,
Which you bloody well asked for by using NO_BOOTMEM=y.
Going down this route; adding hacks for every little thing that does
want bootmem, completely defeats the purpose.
If anything, make the earlycon thing depend on NO_BOOTMEM=n. That also
solves your problem. No earlycon, no panic.
next prev parent reply other threads:[~2018-08-30 10:44 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-30 9:03 [PATCH] x86, mm: Reserver some memory for bootmem allocator for NO_BOOTMEM Feng Tang
2018-08-30 10:44 ` Peter Zijlstra [this message]
2018-08-30 11:12 ` Michal Hocko
2018-08-30 11:54 ` Thomas Gleixner
2018-08-30 12:49 ` Michal Hocko
2018-08-30 12:59 ` Feng Tang
2018-08-30 13:05 ` Thomas Gleixner
2018-08-30 13:19 ` Feng Tang
2018-08-30 13:25 ` Thomas Gleixner
2018-08-30 13:55 ` Feng Tang
2018-08-31 6:15 ` Feng Tang
2018-08-31 11:33 ` Thomas Gleixner
2018-08-31 13:36 ` Feng Tang
2018-09-07 8:17 ` Feng Tang
2018-09-07 10:52 ` Thomas Gleixner
2018-09-10 9:39 ` Feng Tang
2018-09-10 9:53 ` Thomas Gleixner
2018-09-11 6:14 ` Feng Tang
2018-09-15 10:29 ` Thomas Gleixner
2018-09-15 16:47 ` Feng Tang
2018-09-15 17:28 ` Thomas Gleixner
2018-09-16 14:35 ` Feng Tang
2018-09-16 14:43 ` Thomas Gleixner
2018-09-16 15:06 ` Feng Tang
2018-09-17 7:01 ` Feng Tang
2018-09-17 7:01 ` Thomas Gleixner
2018-08-30 12:09 ` Peter Zijlstra
2018-08-30 12:39 ` Michal Hocko
2018-08-30 12:43 ` Feng Tang
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