Changes since 12/7/05
- removed __attribute((unused)) qualifiers from timespec vars (dave hansen)
- use existing timestamping function do_posix_clock_monotonic_gettime() (jay lan)
Changes since 11/14/05
- use nanosecond resolution, adjusted wall clock time for timestamps
instead of sched_clock (akpm, andi, marcelo)
- collect stats only if delay accounting enabled (parag)
- stats collected for delays in all userspace-initiated block I/O
including fsync/fdatasync but not counting waits for async block io events.
11/14/05: First post
delayacct-blkio.patch
Record time spent by a task waiting for completion of
userspace initiated synchronous block I/O. This can help
determine the right I/O priority for the task.
Signed-off-by: Shailabh Nagar <[email protected]>
fs/buffer.c | 6 ++++++
fs/read_write.c | 10 +++++++++-
include/linux/delayacct.h | 4 ++++
include/linux/sched.h | 2 ++
kernel/delayacct.c | 16 ++++++++++++++++
mm/filemap.c | 10 +++++++++-
mm/memory.c | 17 +++++++++++++++--
7 files changed, 61 insertions(+), 4 deletions(-)
Index: linux-2.6.15-rc7/include/linux/sched.h
===================================================================
--- linux-2.6.15-rc7.orig/include/linux/sched.h
+++ linux-2.6.15-rc7/include/linux/sched.h
@@ -546,6 +546,8 @@ struct task_delay_info {
spinlock_t lock;
/* Add stats in pairs: uint64_t delay, uint32_t count */
+ uint64_t blkio_delay; /* wait for sync block io completion */
+ uint32_t blkio_count;
};
#endif
Index: linux-2.6.15-rc7/fs/read_write.c
===================================================================
--- linux-2.6.15-rc7.orig/fs/read_write.c
+++ linux-2.6.15-rc7/fs/read_write.c
@@ -14,6 +14,8 @@
#include <linux/security.h>
#include <linux/module.h>
#include <linux/syscalls.h>
+#include <linux/time.h>
+#include <linux/delayacct.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -224,8 +226,14 @@ ssize_t do_sync_read(struct file *filp,
(ret = filp->f_op->aio_read(&kiocb, buf, len, kiocb.ki_pos)))
wait_on_retry_sync_kiocb(&kiocb);
- if (-EIOCBQUEUED == ret)
+ if (-EIOCBQUEUED == ret) {
+ struct timespec start, end;
+
+ do_posix_clock_monotonic_gettime(&start);
ret = wait_on_sync_kiocb(&kiocb);
+ do_posix_clock_monotonic_gettime(&end);
+ delayacct_blkio(&start, &end);
+ }
*ppos = kiocb.ki_pos;
return ret;
}
Index: linux-2.6.15-rc7/mm/filemap.c
===================================================================
--- linux-2.6.15-rc7.orig/mm/filemap.c
+++ linux-2.6.15-rc7/mm/filemap.c
@@ -28,6 +28,8 @@
#include <linux/blkdev.h>
#include <linux/security.h>
#include <linux/syscalls.h>
+#include <linux/time.h>
+#include <linux/delayacct.h>
#include "filemap.h"
/*
* FIXME: remove all knowledge of the buffer layer from the core VM
@@ -1062,8 +1064,14 @@ generic_file_read(struct file *filp, cha
init_sync_kiocb(&kiocb, filp);
ret = __generic_file_aio_read(&kiocb, &local_iov, 1, ppos);
- if (-EIOCBQUEUED == ret)
+ if (-EIOCBQUEUED == ret) {
+ struct timespec start, end;
+
+ do_posix_clock_monotonic_gettime(&start);
ret = wait_on_sync_kiocb(&kiocb);
+ do_posix_clock_monotonic_gettime(&end);
+ delayacct_blkio(&start, &end);
+ }
return ret;
}
Index: linux-2.6.15-rc7/mm/memory.c
===================================================================
--- linux-2.6.15-rc7.orig/mm/memory.c
+++ linux-2.6.15-rc7/mm/memory.c
@@ -48,6 +48,8 @@
#include <linux/rmap.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/delayacct.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
@@ -2170,11 +2172,22 @@ static inline int handle_pte_fault(struc
old_entry = entry = *pte;
if (!pte_present(entry)) {
if (pte_none(entry)) {
+ int ret;
+ struct timespec start, end;
+
if (!vma->vm_ops || !vma->vm_ops->nopage)
return do_anonymous_page(mm, vma, address,
pte, pmd, write_access);
- return do_no_page(mm, vma, address,
- pte, pmd, write_access);
+
+ if (vma->vm_file)
+ do_posix_clock_monotonic_gettime(&start);
+ ret = do_no_page(mm, vma, address,
+ pte, pmd, write_access);
+ if (vma->vm_file) {
+ do_posix_clock_monotonic_gettime(&end);
+ delayacct_blkio(&start, &end);
+ }
+ return ret;
}
if (pte_file(entry))
return do_file_page(mm, vma, address,
Index: linux-2.6.15-rc7/fs/buffer.c
===================================================================
--- linux-2.6.15-rc7.orig/fs/buffer.c
+++ linux-2.6.15-rc7/fs/buffer.c
@@ -41,6 +41,8 @@
#include <linux/bitops.h>
#include <linux/mpage.h>
#include <linux/bit_spinlock.h>
+#include <linux/time.h>
+#include <linux/delayacct.h>
static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
static void invalidate_bh_lrus(void);
@@ -337,6 +339,7 @@ static long do_fsync(unsigned int fd, in
struct file * file;
struct address_space *mapping;
int ret, err;
+ struct timespec start, end;
ret = -EBADF;
file = fget(fd);
@@ -349,6 +352,7 @@ static long do_fsync(unsigned int fd, in
goto out_putf;
}
+ do_posix_clock_monotonic_gettime(&start);
mapping = file->f_mapping;
current->flags |= PF_SYNCWRITE;
@@ -371,6 +375,8 @@ static long do_fsync(unsigned int fd, in
out_putf:
fput(file);
out:
+ do_posix_clock_monotonic_gettime(&end);
+ delayacct_blkio(&start, &end);
return ret;
}
Index: linux-2.6.15-rc7/include/linux/delayacct.h
===================================================================
--- linux-2.6.15-rc7.orig/include/linux/delayacct.h
+++ linux-2.6.15-rc7/include/linux/delayacct.h
@@ -19,8 +19,12 @@
#ifdef CONFIG_TASK_DELAY_ACCT
extern int delayacct_on; /* Delay accounting turned on/off */
extern void delayacct_tsk_init(struct task_struct *tsk);
+extern void delayacct_blkio(struct timespec *start, struct timespec *end);
#else
static inline void delayacct_tsk_init(struct task_struct *tsk)
{}
+static inline void delayacct_blkio(struct timespec *start, struct timespec *end)
+{}
+
#endif /* CONFIG_TASK_DELAY_ACCT */
#endif /* _LINUX_TASKDELAYS_H */
Index: linux-2.6.15-rc7/kernel/delayacct.c
===================================================================
--- linux-2.6.15-rc7.orig/kernel/delayacct.c
+++ linux-2.6.15-rc7/kernel/delayacct.c
@@ -12,6 +12,7 @@
*/
#include <linux/sched.h>
+#include <linux/time.h>
int delayacct_on=1; /* Delay accounting turned on/off */
@@ -34,3 +35,18 @@ static int __init delayacct_init(void)
return 0;
}
core_initcall(delayacct_init);
+
+inline void delayacct_blkio(struct timespec *start, struct timespec *end)
+{
+ unsigned long long delay;
+
+ if (!delayacct_on)
+ return;
+
+ delay = timespec_diff_ns(start, end);
+
+ spin_lock(¤t->delays.lock);
+ current->delays.blkio_delay += delay;
+ current->delays.blkio_count++;
+ spin_unlock(¤t->delays.lock);
+}
-
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