The patch titled
task IO accounting: correctly account threads IO statistics
has been added to the -mm tree. Its filename is
task-io-accounting-correctly-account-threads-io-statistics.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: task IO accounting: correctly account threads IO statistics
From: Andrea Righi <righi.andrea@xxxxxxxxx>
Oleg Nesterov points out that we should check that the task is still alive
before we iterate over the threads. This patch includes a fixup for this.
Also simplify do_io_accounting() implementation.
Signed-off-by: Andrea Righi <righi.andrea@xxxxxxxxx>
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/base.c | 56 ++++++++++++++++++-----------------------------
1 file changed, 22 insertions(+), 34 deletions(-)
diff -puN fs/proc/base.c~task-io-accounting-correctly-account-threads-io-statistics fs/proc/base.c
--- a/fs/proc/base.c~task-io-accounting-correctly-account-threads-io-statistics
+++ a/fs/proc/base.c
@@ -2406,35 +2406,18 @@ static int do_io_accounting(struct task_
u64 rchar, wchar, syscr, syscw;
struct task_io_accounting ioac;
- if (!whole) {
- rchar = task->rchar;
- wchar = task->wchar;
- syscr = task->syscr;
- syscw = task->syscw;
- memcpy(&ioac, &task->ioac, sizeof(ioac));
- } else {
- unsigned long flags;
- struct task_struct *t = task;
- rchar = wchar = syscr = syscw = 0;
- memset(&ioac, 0, sizeof(ioac));
-
- rcu_read_lock();
- do {
- rchar += t->rchar;
- wchar += t->wchar;
- syscr += t->syscr;
- syscw += t->syscw;
+ rchar = task->rchar;
+ wchar = task->wchar;
+ syscr = task->syscr;
+ syscw = task->syscw;
+ memcpy(&ioac, &task->ioac, sizeof(ioac));
- ioac.read_bytes += t->ioac.read_bytes;
- ioac.write_bytes += t->ioac.write_bytes;
- ioac.cancelled_write_bytes +=
- t->ioac.cancelled_write_bytes;
- t = next_thread(t);
- } while (t != task);
- rcu_read_unlock();
+ if (whole) {
+ unsigned long flags;
if (lock_task_sighand(task, &flags)) {
struct signal_struct *sig = task->signal;
+ struct task_struct *t = task;
rchar += sig->rchar;
wchar += sig->wchar;
@@ -2445,11 +2428,20 @@ static int do_io_accounting(struct task_
ioac.write_bytes += sig->ioac.write_bytes;
ioac.cancelled_write_bytes +=
sig->ioac.cancelled_write_bytes;
-
+ while_each_thread(task, t) {
+ rchar += t->rchar;
+ wchar += t->wchar;
+ syscr += t->syscr;
+ syscw += t->syscw;
+
+ ioac.read_bytes += t->ioac.read_bytes;
+ ioac.write_bytes += t->ioac.write_bytes;
+ ioac.cancelled_write_bytes +=
+ t->ioac.cancelled_write_bytes;
+ }
unlock_task_sighand(task, &flags);
}
}
-
return sprintf(buffer,
"rchar: %llu\n"
"wchar: %llu\n"
@@ -2458,13 +2450,9 @@ static int do_io_accounting(struct task_
"read_bytes: %llu\n"
"write_bytes: %llu\n"
"cancelled_write_bytes: %llu\n",
- (unsigned long long)rchar,
- (unsigned long long)wchar,
- (unsigned long long)syscr,
- (unsigned long long)syscw,
- (unsigned long long)ioac.read_bytes,
- (unsigned long long)ioac.write_bytes,
- (unsigned long long)ioac.cancelled_write_bytes);
+ rchar, wchar, syscr, syscw,
+ ioac.read_bytes, ioac.write_bytes,
+ ioac.cancelled_write_bytes);
}
static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
_
Patches currently in -mm which might be from righi.andrea@xxxxxxxxx are
origin.patch
task-io-accounting-correctly-account-threads-io-statistics.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
