task IO accounting: improve code readability
Put all i/o statistics in struct proc_io_accounting and use inline functions to
initialize and increment statistics, removing a lot of single variable
assignments.
This also reduces the kernel size as following (with CONFIG_TASK_XACCT=y and
CONFIG_TASK_IO_ACCOUNTING=y).
text data bss dec hex filename
11651 0 0 11651 2d83 kernel/exit.o.before
11619 0 0 11619 2d63 kernel/exit.o.after
10886 132 136 11154 2b92 kernel/fork.o.before
10758 132 136 11026 2b12 kernel/fork.o.after
3082029 807968 4818600 8708597 84e1f5 vmlinux.o.before
3081869 807968 4818600 8708437 84e155 vmlinux.o.after
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index 0caf590..eb4d647 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -121,18 +121,7 @@
sig->nivcsw += tsk->nivcsw;
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
-#ifdef CONFIG_TASK_XACCT
- sig->rchar += tsk->rchar;
- sig->wchar += tsk->wchar;
- sig->syscr += tsk->syscr;
- sig->syscw += tsk->syscw;
-#endif /* CONFIG_TASK_XACCT */
-#ifdef CONFIG_TASK_IO_ACCOUNTING
- sig->ioac.read_bytes += tsk->ioac.read_bytes;
- sig->ioac.write_bytes += tsk->ioac.write_bytes;
- sig->ioac.cancelled_write_bytes +=
- tsk->ioac.cancelled_write_bytes;
-#endif /* CONFIG_TASK_IO_ACCOUNTING */
+ task_io_accounting_add(&sig->ioac, &tsk->ioac);
sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
sig = NULL; /* Marker for below. */
}
@@ -1363,21 +1352,8 @@
psig->coublock +=
task_io_get_oublock(p) +
sig->oublock + sig->coublock;
-#ifdef CONFIG_TASK_XACCT
- psig->rchar += p->rchar + sig->rchar;
- psig->wchar += p->wchar + sig->wchar;
- psig->syscr += p->syscr + sig->syscr;
- psig->syscw += p->syscw + sig->syscw;
-#endif /* CONFIG_TASK_XACCT */
-#ifdef CONFIG_TASK_IO_ACCOUNTING
- psig->ioac.read_bytes +=
- p->ioac.read_bytes + sig->ioac.read_bytes;
- psig->ioac.write_bytes +=
- p->ioac.write_bytes + sig->ioac.write_bytes;
- psig->ioac.cancelled_write_bytes +=
- p->ioac.cancelled_write_bytes +
- sig->ioac.cancelled_write_bytes;
-#endif /* CONFIG_TASK_IO_ACCOUNTING */
+ task_io_accounting_add(&psig->ioac, &p->ioac);
+ task_io_accounting_add(&psig->ioac, &sig->ioac);
spin_unlock_irq(&p->parent->sighand->siglock);
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 5e050c1..8214ba7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -806,12 +806,7 @@
sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
-#ifdef CONFIG_TASK_XACCT
- sig->rchar = sig->wchar = sig->syscr = sig->syscw = 0;
-#endif
-#ifdef CONFIG_TASK_IO_ACCOUNTING
- memset(&sig->ioac, 0, sizeof(sig->ioac));
-#endif
+ task_io_accounting_init(&sig->ioac);
sig->sum_sched_runtime = 0;
INIT_LIST_HEAD(&sig->cpu_timers[0]);
INIT_LIST_HEAD(&sig->cpu_timers[1]);
@@ -994,13 +989,7 @@
p->last_switch_timestamp = 0;
#endif
-#ifdef CONFIG_TASK_XACCT
- p->rchar = 0; /* I/O counter: bytes read */
- p->wchar = 0; /* I/O counter: bytes written */
- p->syscr = 0; /* I/O counter: read syscalls */
- p->syscw = 0; /* I/O counter: write syscalls */
-#endif
- task_io_accounting_init(p);
+ task_io_accounting_init(&p->ioac);
acct_clear_integrals(p);
p->it_virt_expires = cputime_zero;
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 3da47cc..f9cd256 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -94,14 +94,14 @@
stats->hiwater_vm = mm->hiwater_vm * PAGE_SIZE / KB;
mmput(mm);
}
- stats->read_char = p->rchar;
- stats->write_char = p->wchar;
- stats->read_syscalls = p->syscr;
- stats->write_syscalls = p->syscw;
+ stats->read_char = p->ioac.chr.rchar;
+ stats->write_char = p->ioac.chr.wchar;
+ stats->read_syscalls = p->ioac.chr.syscr;
+ stats->write_syscalls = p->ioac.chr.syscw;
#ifdef CONFIG_TASK_IO_ACCOUNTING
- stats->read_bytes = p->ioac.read_bytes;
- stats->write_bytes = p->ioac.write_bytes;
- stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes;
+ stats->read_bytes = p->ioac.blk.read_bytes;
+ stats->write_bytes = p->ioac.blk.write_bytes;
+ stats->cancelled_write_bytes = p->ioac.blk.cancelled_write_bytes;
#else
stats->read_bytes = 0;
stats->write_bytes = 0;