From: Thomas Gleixner <tglx@linutronix.de>
To: Marcelo Tosatti <mtosatti@redhat.com>, linux-kernel@vger.kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>,
Juri Lelli <juri.lelli@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Leonardo Bras <leobras@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [patch 12/12] x86/cacheinfo.c: check for block interference CPUs
Date: Wed, 07 Feb 2024 13:41:36 +0100 [thread overview]
Message-ID: <87eddomoov.ffs@tglx> (raw)
In-Reply-To: <20240206185710.142514323@redhat.com>
On Tue, Feb 06 2024 at 15:49, Marcelo Tosatti wrote:
> @@ -396,6 +397,7 @@ static void amd_l3_disable_index(struct
> * disable index in all 4 subcaches
> */
> for (i = 0; i < 4; i++) {
> + int ret;
> u32 reg = idx | (i << 20);
>
> if (!nb->l3_cache.subcaches[i])
> @@ -409,6 +411,7 @@ static void amd_l3_disable_index(struct
> * is not sufficient.
> */
> ret = wbinvd_on_cpu(cpu);
> + WARN_ON(ret == -EPERM);
What? You create inconsistent state here.
> - amd_l3_disable_index(nb, cpu, slot, index);
> + ret = 0;
> + idx = block_interf_srcu_read_lock();
> +
> + if (block_interf_cpu(cpu))
> + ret = -EPERM;
> + else
> + amd_l3_disable_index(nb, cpu, slot, index);
> +
> + block_interf_srcu_read_unlock(idx);
Again. This is a root only operation.
This whole patch series is just voodoo programming with zero
justification for the mess it creates.
Thanks,
tglx
.
next prev parent reply other threads:[~2024-02-07 12:41 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-06 18:49 [patch 00/12] cpu isolation: infra to block interference to select CPUs Marcelo Tosatti
2024-02-06 18:49 ` [patch 01/12] cpu isolation: basic block interference infrastructure Marcelo Tosatti
2024-02-06 18:49 ` [patch 02/12] introduce smp_call_func_single_fail Marcelo Tosatti
2024-02-06 18:49 ` [patch 03/12] Introduce _fail variants of stop_machine functions Marcelo Tosatti
2024-02-06 18:49 ` [patch 04/12] clockevent unbind: use smp_call_func_single_fail Marcelo Tosatti
2024-02-07 11:55 ` Thomas Gleixner
2024-02-07 12:51 ` Marcelo Tosatti
2024-02-11 8:52 ` Thomas Gleixner
2024-02-14 18:58 ` Marcelo Tosatti
2024-02-06 18:49 ` [patch 05/12] timekeeping_notify: use stop_machine_fail when appropriate Marcelo Tosatti
2024-02-07 11:57 ` Thomas Gleixner
2024-02-07 12:58 ` Marcelo Tosatti
2024-02-08 15:23 ` Thomas Gleixner
2024-02-09 15:30 ` Marcelo Tosatti
2024-02-12 15:29 ` Thomas Gleixner
2024-02-06 18:49 ` [patch 06/12] perf_event_open: check for block interference CPUs Marcelo Tosatti
2024-02-06 18:49 ` [patch 07/12] mtrr_add_page/mtrr_del_page: " Marcelo Tosatti
2024-02-06 18:49 ` [patch 08/12] arm64 kernel/topology: use smp_call_function_single_fail Marcelo Tosatti
2024-02-06 18:49 ` [patch 09/12] AMD MCE: use smp_call_func_single_fail Marcelo Tosatti
2024-02-06 18:49 ` [patch 10/12] x86/mce/inject.c: fail if target cpu is block interference Marcelo Tosatti
2024-02-06 18:49 ` [patch 11/12] x86/resctrl: use smp_call_function_single_fail Marcelo Tosatti
2024-02-12 15:19 ` Thomas Gleixner
2024-02-14 18:59 ` Marcelo Tosatti
2024-02-06 18:49 ` [patch 12/12] x86/cacheinfo.c: check for block interference CPUs Marcelo Tosatti
2024-02-07 12:41 ` Thomas Gleixner [this message]
2024-02-07 13:10 ` Marcelo Tosatti
2024-02-07 13:16 ` Marcelo Tosatti
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