On Tue, Oct 04, 2022 at 03:25:37AM -0300, Leonardo Bras wrote:
> Currently pcrypt_aead_init_tfm() will pick callback cpus (ctx->cb_cpu)
> from any online cpus. Later padata_reorder() will queue_work_on() the
> chosen cb_cpu.
>
> This is undesired if the chosen cb_cpu is listed as isolated (i.e. using
> isolcpus=... kernel parameter), since the work queued will interfere with
> the workload on the isolated cpu.
>
> Make sure isolated cpus are not used for pcrypt.
>
> Signed-off-by: Leonardo Bras <leobras@xxxxxxxxxx>
> ---
> crypto/pcrypt.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
> index 9d10b846ccf73..9017d08c91a8d 100644
> --- a/crypto/pcrypt.c
> +++ b/crypto/pcrypt.c
> @@ -16,6 +16,7 @@
> #include <linux/kobject.h>
> #include <linux/cpu.h>
> #include <crypto/pcrypt.h>
> +#include <linux/sched/isolation.h>
>
> static struct padata_instance *pencrypt;
> static struct padata_instance *pdecrypt;
> @@ -175,13 +176,16 @@ static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
> struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst);
> struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
> struct crypto_aead *cipher;
> + struct cpumask non_isolated;
> +
> + cpumask_and(&non_isolated, cpu_online_mask, housekeeping_cpumask(HK_TYPE_DOMAIN));
Since certain systems do not use isolcpus=domain, so please use a flag
that is setup by nohz_full=, for example HK_FLAG_MISC:
static int __init housekeeping_nohz_full_setup(char *str)
{
unsigned long flags;
flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |
HK_FLAG_MISC | HK_FLAG_KTHREAD;
return housekeeping_setup(str, flags);
}
__setup("nohz_full=", housekeeping_nohz_full_setup);
Also, shouldnt you use cpumask_t ?
Looks good otherwise.
Thanks!
>
> cpu_index = (unsigned int)atomic_inc_return(&ictx->tfm_count) %
> - cpumask_weight(cpu_online_mask);
> + cpumask_weight(&non_isolated);
>
> - ctx->cb_cpu = cpumask_first(cpu_online_mask);
> + ctx->cb_cpu = cpumask_first(&non_isolated);
> for (cpu = 0; cpu < cpu_index; cpu++)
> - ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
> + ctx->cb_cpu = cpumask_next(ctx->cb_cpu, &non_isolated);
>
> cipher = crypto_spawn_aead(&ictx->spawn);
>
> --
> 2.37.3
>
>
