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/include/linux/sched.h b/include/linux/sched.h
index f59318a..034c1ca 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -505,10 +505,7 @@
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
unsigned long inblock, oublock, cinblock, coublock;
-#ifdef CONFIG_TASK_XACCT
- u64 rchar, wchar, syscr, syscw;
-#endif
- struct task_io_accounting ioac;
+ struct proc_io_accounting ioac;
/*
* Cumulative ns of scheduled CPU time for dead threads in the
@@ -1256,11 +1253,7 @@
unsigned long ptrace_message;
siginfo_t *last_siginfo; /* For ptrace use. */
-#ifdef CONFIG_TASK_XACCT
-/* i/o counters(bytes read/written, #syscalls */
- u64 rchar, wchar, syscr, syscw;
-#endif
- struct task_io_accounting ioac;
+ struct proc_io_accounting ioac;
#if defined(CONFIG_TASK_XACCT)
u64 acct_rss_mem1; /* accumulated rss usage */
u64 acct_vm_mem1; /* accumulated virtual memory usage */
@@ -2190,22 +2183,22 @@
#ifdef CONFIG_TASK_XACCT
static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
{
- tsk->rchar += amt;
+ tsk->ioac.chr.rchar += amt;
}
static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
{
- tsk->wchar += amt;
+ tsk->ioac.chr.wchar += amt;
}
static inline void inc_syscr(struct task_struct *tsk)
{
- tsk->syscr++;
+ tsk->ioac.chr.syscr++;
}
static inline void inc_syscw(struct task_struct *tsk)
{
- tsk->syscw++;
+ tsk->ioac.chr.syscw++;
}
#else
static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
diff --git a/include/linux/task_io_accounting.h b/include/linux/task_io_accounting.h
index 44d00e9..165390f 100644
--- a/include/linux/task_io_accounting.h
+++ b/include/linux/task_io_accounting.h
@@ -1,5 +1,5 @@
/*
- * task_io_accounting: a structure which is used for recording a single task's
+ * proc_io_accounting: a structure which is used for recording a single task's
* IO statistics.
*
* Don't include this header file directly - it is designed to be dragged in via
@@ -8,6 +8,22 @@
* Blame akpm@osdl.org for all this.
*/
+#ifdef CONFIG_TASK_XACCT
+struct task_chr_io_accounting {
+ /* bytes read */
+ u64 rchar;
+ /* bytes written */
+ u64 wchar;
+ /* # of read syscalls */
+ u64 syscr;
+ /* # of write syscalls */
+ u64 syscw;
+};
+#else /* CONFIG_TASK_XACCT */
+struct task_chr_io_accounting {
+};
+#endif /* CONFIG_TASK_XACCT */
+
#ifdef CONFIG_TASK_IO_ACCOUNTING
struct task_io_accounting {
/*
@@ -31,7 +47,12 @@
*/
u64 cancelled_write_bytes;
};
-#else
+#else /* CONFIG_TASK_IO_ACCOUNTING */
struct task_io_accounting {
};
-#endif
+#endif /* CONFIG_TASK_IO_ACCOUNTING */
+
+struct proc_io_accounting {
+ struct task_chr_io_accounting chr;
+ struct task_io_accounting blk;
+};
diff --git a/include/linux/task_io_accounting_ops.h b/include/linux/task_io_accounting_ops.h
index ff46c6f..e6f958e 100644
--- a/include/linux/task_io_accounting_ops.h
+++ b/include/linux/task_io_accounting_ops.h
@@ -9,7 +9,7 @@
#ifdef CONFIG_TASK_IO_ACCOUNTING
static inline void task_io_account_read(size_t bytes)
{
- current->ioac.read_bytes += bytes;
+ current->ioac.blk.read_bytes += bytes;
}
/*
@@ -18,12 +18,12 @@
*/
static inline unsigned long task_io_get_inblock(const struct task_struct *p)
{
- return p->ioac.read_bytes >> 9;
+ return p->ioac.blk.read_bytes >> 9;
}
static inline void task_io_account_write(size_t bytes)
{
- current->ioac.write_bytes += bytes;
+ current->ioac.blk.write_bytes += bytes;
}
/*
@@ -32,17 +32,25 @@
*/
static inline unsigned long task_io_get_oublock(const struct task_struct *p)
{
- return p->ioac.write_bytes >> 9;
+ return p->ioac.blk.write_bytes >> 9;
}
static inline void task_io_account_cancelled_write(size_t bytes)
{
- current->ioac.cancelled_write_bytes += bytes;
+ current->ioac.blk.cancelled_write_bytes += bytes;
}
-static inline void task_io_accounting_init(struct task_struct *tsk)
+static inline void task_io_accounting_init(struct proc_io_accounting *ioac)
{
- memset(&tsk->ioac, 0, sizeof(tsk->ioac));
+ memset(ioac, 0, sizeof(*ioac));
+}
+
+static inline void task_blk_io_accounting_add(struct proc_io_accounting *dst,
+ struct proc_io_accounting *src)
+{
+ dst->blk.read_bytes += src->blk.read_bytes;
+ dst->blk.write_bytes += src->blk.write_bytes;
+ dst->blk.cancelled_write_bytes += src->blk.cancelled_write_bytes;
}
#else
@@ -69,9 +77,37 @@
{
}
-static inline void task_io_accounting_init(struct task_struct *tsk)
+static inline void task_io_accounting_init(struct proc_io_accounting *ioac)
{
}
-#endif /* CONFIG_TASK_IO_ACCOUNTING */
-#endif /* __TASK_IO_ACCOUNTING_OPS_INCLUDED */
+static inline void task_blk_io_accounting_add(struct proc_io_accounting *dst,
+ struct proc_io_accounting *src)
+{
+}
+
+#endif /* CONFIG_TASK_IO_ACCOUNTING */
+
+#ifdef CONFIG_TASK_XACCT
+static inline void task_chr_io_accounting_add(struct proc_io_accounting *dst,
+ struct proc_io_accounting *src)
+{
+ dst->chr.rchar += src->chr.rchar;
+ dst->chr.wchar += src->chr.wchar;
+ dst->chr.syscr += src->chr.syscr;
+ dst->chr.syscw += src->chr.syscw;
+}
+#else
+static inline void task_chr_io_accounting_add(struct proc_io_accounting *dst,
+ struct proc_io_accounting *src)
+{
+}
+#endif /* CONFIG_TASK_XACCT */
+
+static inline void task_io_accounting_add(struct proc_io_accounting *dst,
+ struct proc_io_accounting *src)
+{
+ task_chr_io_accounting_add(dst, src);
+ task_blk_io_accounting_add(dst, src);
+}
+#endif /* __TASK_IO_ACCOUNTING_OPS_INCLUDED */