From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Cc: anju@linux.vnet.ibm.com, paulus@samba.org, gpiccoli@linux.vnet.ibm.com
Subject: Re: powerpc/perf: Fix IMC allocation routine
Date: Wed, 1 Nov 2017 16:17:42 +1100 (AEDT) [thread overview]
Message-ID: <3yRc122gtGz9t2m@ozlabs.org> (raw)
In-Reply-To: <20171019194133.27485-1-gpiccoli@linux.vnet.ibm.com>
On Thu, 2017-10-19 at 19:41:33 UTC, "Guilherme G. Piccoli" wrote:
> When setting nr_cpus=1, we observed a crash in IMC code during boot
> due to a missing allocation: basically, IMC code is taking the number
> of threads into account in imc_mem_init() and if we manually set
> nr_cpus for a value that is not multiple of the number of threads per
> core, an integer division in that function will discard the decimal
> portion, leading IMC to not allocate one mem_info struct. This causes
> a NULL pointer dereference later, on is_core_imc_mem_inited().
>
> This patch just rounds that division up, fixing the bug.
>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/0b167f11085a34281349f395d20005
cheers
prev parent reply other threads:[~2017-11-01 5:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 19:41 [PATCH] powerpc/perf: Fix IMC allocation routine Guilherme G. Piccoli
2017-10-24 8:34 ` Anju T Sudhakar
2017-10-24 12:17 ` Guilherme G. Piccoli
2017-11-01 5:17 ` Michael Ellerman [this message]
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