| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <1259894705.2076.1249.camel@pasglop>
Date: Fri, 04 Dec 2009 13:45:05 +1100
From: Benjamin Herrenschmidt <benh@...nel.crashing.org>
To: arun@...ux.vnet.ibm.com
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Ingo Molnar <mingo@...e.hu>,
Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
Dipankar Sarma <dipankar@...ibm.com>,
Balbir Singh <balbir@...ibm.com>,
Venkatesh Pallipadi <venkatesh.pallipadi@...el.com>,
linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
linux-arch@...r.kernel.org, linux-acpi@...r.kernel.org
Subject: Re: [v10 PATCH 6/9]: pSeries/cpuidle: refactor pseries idle loops
On Wed, 2009-12-02 at 15:31 +0530, Arun R Bharadwaj wrote:
> * Arun R Bharadwaj <arun@...ux.vnet.ibm.com> [2009-12-02 15:24:27]:
>
> This patch removes the routines, pseries_shared_idle_sleep and
> pseries_dedicated_idle_sleep, since this is implemented as a part
> of arch/powerpc/platform/pseries/processor_idle.c
>
> Also, similar to x86, call cpuidle_idle_call from cpu_idle() idle
> loop instead of ppc_md.power_save.
Tentative NAK... you remove the code before you put a replacement in, or
did I miss something ?
IE. That patch breaks Idle on all powerpc platform it would think..
Cheers,
Ben.
>
> Signed-off-by: Arun R Bharadwaj <arun@...ux.vnet.ibm.com>
> ---
> arch/powerpc/kernel/idle.c | 58 ++++++++++-----------
> arch/powerpc/platforms/pseries/setup.c | 89 ---------------------------------
> 2 files changed, 30 insertions(+), 117 deletions(-)
>
> Index: linux.trees.git/arch/powerpc/platforms/pseries/setup.c
> ===================================================================
> --- linux.trees.git.orig/arch/powerpc/platforms/pseries/setup.c
> +++ linux.trees.git/arch/powerpc/platforms/pseries/setup.c
> @@ -75,9 +75,6 @@ EXPORT_SYMBOL(CMO_PageSize);
>
> int fwnmi_active; /* TRUE if an FWNMI handler is present */
>
> -static void pseries_shared_idle_sleep(void);
> -static void pseries_dedicated_idle_sleep(void);
> -
> static struct device_node *pSeries_mpic_node;
>
> static void pSeries_show_cpuinfo(struct seq_file *m)
> @@ -297,18 +294,8 @@ static void __init pSeries_setup_arch(vo
> pSeries_nvram_init();
>
> /* Choose an idle loop */
> - if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
> + if (firmware_has_feature(FW_FEATURE_SPLPAR))
> vpa_init(boot_cpuid);
> - if (get_lppaca()->shared_proc) {
> - printk(KERN_DEBUG "Using shared processor idle loop\n");
> - ppc_md.power_save = pseries_shared_idle_sleep;
> - } else {
> - printk(KERN_DEBUG "Using dedicated idle loop\n");
> - ppc_md.power_save = pseries_dedicated_idle_sleep;
> - }
> - } else {
> - printk(KERN_DEBUG "Using default idle loop\n");
> - }
>
> if (firmware_has_feature(FW_FEATURE_LPAR))
> ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
> @@ -496,80 +483,6 @@ static int __init pSeries_probe(void)
> return 1;
> }
>
> -
> -DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
> -
> -static void pseries_dedicated_idle_sleep(void)
> -{
> - unsigned int cpu = smp_processor_id();
> - unsigned long start_snooze;
> - unsigned long in_purr, out_purr;
> -
> - /*
> - * Indicate to the HV that we are idle. Now would be
> - * a good time to find other work to dispatch.
> - */
> - get_lppaca()->idle = 1;
> - get_lppaca()->donate_dedicated_cpu = 1;
> - in_purr = mfspr(SPRN_PURR);
> -
> - /*
> - * We come in with interrupts disabled, and need_resched()
> - * has been checked recently. If we should poll for a little
> - * while, do so.
> - */
> - if (__get_cpu_var(smt_snooze_delay)) {
> - start_snooze = get_tb() +
> - __get_cpu_var(smt_snooze_delay) * tb_ticks_per_usec;
> - local_irq_enable();
> - set_thread_flag(TIF_POLLING_NRFLAG);
> -
> - while (get_tb() < start_snooze) {
> - if (need_resched() || cpu_is_offline(cpu))
> - goto out;
> - ppc64_runlatch_off();
> - HMT_low();
> - HMT_very_low();
> - }
> -
> - HMT_medium();
> - clear_thread_flag(TIF_POLLING_NRFLAG);
> - smp_mb();
> - local_irq_disable();
> - if (need_resched() || cpu_is_offline(cpu))
> - goto out;
> - }
> -
> - cede_processor();
> -
> -out:
> - HMT_medium();
> - out_purr = mfspr(SPRN_PURR);
> - get_lppaca()->wait_state_cycles += out_purr - in_purr;
> - get_lppaca()->donate_dedicated_cpu = 0;
> - get_lppaca()->idle = 0;
> -}
> -
> -static void pseries_shared_idle_sleep(void)
> -{
> - /*
> - * Indicate to the HV that we are idle. Now would be
> - * a good time to find other work to dispatch.
> - */
> - get_lppaca()->idle = 1;
> -
> - /*
> - * Yield the processor to the hypervisor. We return if
> - * an external interrupt occurs (which are driven prior
> - * to returning here) or if a prod occurs from another
> - * processor. When returning here, external interrupts
> - * are enabled.
> - */
> - cede_processor();
> -
> - get_lppaca()->idle = 0;
> -}
> -
> static int pSeries_pci_probe_mode(struct pci_bus *bus)
> {
> if (firmware_has_feature(FW_FEATURE_LPAR))
> Index: linux.trees.git/arch/powerpc/kernel/idle.c
> ===================================================================
> --- linux.trees.git.orig/arch/powerpc/kernel/idle.c
> +++ linux.trees.git/arch/powerpc/kernel/idle.c
> @@ -25,6 +25,7 @@
> #include <linux/cpu.h>
> #include <linux/sysctl.h>
> #include <linux/tick.h>
> +#include <linux/cpuidle.h>
>
> #include <asm/system.h>
> #include <asm/processor.h>
> @@ -46,6 +47,14 @@ static int __init powersave_off(char *ar
> }
> __setup("powersave=off", powersave_off);
>
> +#ifndef CONFIG_CPU_IDLE
> +void cpuidle_idle_call(void)
> +{
> + local_irq_enable();
> + cpu_relax();
> +}
> +#endif
> +
> /*
> * The body of the idle task.
> */
> @@ -60,35 +69,26 @@ void cpu_idle(void)
> while (!need_resched() && !cpu_should_die()) {
> ppc64_runlatch_off();
>
> - if (ppc_md.power_save) {
> - clear_thread_flag(TIF_POLLING_NRFLAG);
> - /*
> - * smp_mb is so clearing of TIF_POLLING_NRFLAG
> - * is ordered w.r.t. need_resched() test.
> - */
> - smp_mb();
> - local_irq_disable();
> -
> - /* Don't trace irqs off for idle */
> - stop_critical_timings();
> -
> - /* check again after disabling irqs */
> - if (!need_resched() && !cpu_should_die())
> - ppc_md.power_save();
> -
> - start_critical_timings();
> -
> - local_irq_enable();
> - set_thread_flag(TIF_POLLING_NRFLAG);
> -
> - } else {
> - /*
> - * Go into low thread priority and possibly
> - * low power mode.
> - */
> - HMT_low();
> - HMT_very_low();
> - }
> + clear_thread_flag(TIF_POLLING_NRFLAG);
> + /*
> + * smp_mb is so clearing of TIF_POLLING_NRFLAG
> + * is ordered w.r.t. need_resched() test.
> + */
> + smp_mb();
> + local_irq_disable();
> +
> + /* Don't trace irqs off for idle */
> + stop_critical_timings();
> +
> + /* check again after disabling irqs */
> + if (!need_resched() && !cpu_should_die())
> + cpuidle_idle_call();
> +
> + start_critical_timings();
> +
> + local_irq_enable();
> + set_thread_flag(TIF_POLLING_NRFLAG);
> +
> }
>
> HMT_medium();
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists