Messages in this thread Patch in this message | | | From | Srikar Dronamraju <> | Subject | [PATCH v5 08/10] powerpc/smp: Allocate cpumask only after searching thread group | Date | Mon, 10 Aug 2020 12:48:32 +0530 |
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If allocated earlier and the search fails, then cpu_l1_cache_map cpumask is unnecessarily cleared. However cpu_l1_cache_map can be allocated / cleared after we search thread group.
Please note CONFIG_CPUMASK_OFFSTACK is not set on Powerpc. Hence cpumask allocated by zalloc_cpumask_var_node is never freed.
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Valentin Schneider <valentin.schneider@arm.com> Cc: Jordan Niethe <jniethe5@gmail.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog v4 ->v5: Updated commit msg on why cpumask need not be freed. (Michael Ellerman)
arch/powerpc/kernel/smp.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 7403fdcf3821..0536ac06876b 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -789,10 +789,6 @@ static int init_cpu_l1_cache_map(int cpu) if (err) goto out; - zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu), - GFP_KERNEL, - cpu_to_node(cpu)); - cpu_group_start = get_cpu_thread_group_start(cpu, &tg); if (unlikely(cpu_group_start == -1)) { @@ -801,6 +797,9 @@ static int init_cpu_l1_cache_map(int cpu) goto out; } + zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu), + GFP_KERNEL, cpu_to_node(cpu)); + for (i = first_thread; i < first_thread + threads_per_core; i++) { int i_group_start = get_cpu_thread_group_start(i, &tg); -- 2.18.2
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