From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hidetoshi Seto Date: Tue, 16 Oct 2007 13:41:48 +0000 Subject: [PATCH 9/9] ia64: VIRT_CPU_ACCOUNTING (accurate cpu time accounting) Message-Id: <4714BF9C.6090308@jp.fujitsu.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org > [9/9] ia64_acct_get_vtime.patch Now all check points are ready. We already cumulate cycles for stime/utime on kernel entrance/exit, so what we need to do is reflecting them into stime/utime of the thread, after translating cycles to nsec. As I already mentioned, this reflection are required to be done in: - context switch - account_system_vtime() - irq_enter - irq_exit - softirq entrance - softirq exit >From these points, we add calls of followings: 　account_system_time() 　account_user_time() to reflect the state-transition based cpu time. And beside of this, we delete these calls from timer_interrupt not to reflect the tick-sampling based cpu time. After all, we get feature of VIRT_CPU_ACCOUNTING on ia64. Thanks, H.Seto Signed-off-by: Hidetoshi Seto --- arch/ia64/kernel/time.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 42 insertions(+), 5 deletions(-) Index: linux-2.6.23/arch/ia64/kernel/time.c =================================--- linux-2.6.23.orig/arch/ia64/kernel/time.c +++ linux-2.6.23/arch/ia64/kernel/time.c @@ -64,9 +64,32 @@ #include #include +#define cycle_to_cputime(cyc) \ + (cputime_t)(((cyc)*local_cpu_data->nsec_per_cyc) >> IA64_NSEC_PER_CYC_SHIFT) + void ia64_account_on_switch(struct task_struct *prev, struct task_struct *next) { + struct thread_info *pi = task_thread_info(prev); + struct thread_info *ni = task_thread_info(next); + unsigned long flags; + __u64 now; + + local_irq_save(flags); + + now = ia64_get_itc(); + + account_system_time(prev, 0, + cycle_to_cputime(pi->ac_stime + (now - pi->ac_stamp))); + pi->ac_stime = 0; + + if (pi->ac_utime) { + account_user_time(prev, cycle_to_cputime(pi->ac_utime)); + pi->ac_utime = 0; + } + + pi->ac_stamp = ni->ac_stamp = now; + local_irq_restore(flags); } /* @@ -75,7 +98,26 @@ */ void account_system_vtime(struct task_struct *tsk) { + struct thread_info *ti = task_thread_info(tsk); + unsigned long flags; + __u64 now; + + local_irq_save(flags); + + now = ia64_get_itc(); + + account_system_time(tsk, 0, + cycle_to_cputime(ti->ac_stime + (now - ti->ac_stamp))); + ti->ac_stime = 0; + + if (ti->ac_utime) { + account_user_time(tsk, cycle_to_cputime(ti->ac_utime)); + ti->ac_utime = 0; + } + + ti->ac_stamp = now; + local_irq_restore(flags); } /* @@ -87,11 +129,6 @@ struct task_struct *p = current; int cpu = smp_processor_id(); - /* Note: this timer irq context must be accounted for as well. */ - if (user_tick) - account_user_time(p, jiffies_to_cputime(1)); - else - account_system_time(p, HARDIRQ_OFFSET, jiffies_to_cputime(1)); run_local_timers(); if (rcu_pending(cpu)) rcu_check_callbacks(cpu, user_tick);