linux/kernel/acct.c, branch v2.6.18.7

[PATCH] Fix sighand->siglock usage in kernel/acct.c

2006-07-15T04:53:54Z

IRQs must be disabled before taking ->siglock. Noticed by lockdep. Signed-off-by: OGAWA Hirofumi Cc: Arjan van de Ven Cc: Ingo Molnar Cc: "Eric W. Biederman" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36Z

Signed-off-by: Jörn Engel Signed-off-by: Adrian Bunk

[PATCH] fix kernel-doc in kernel/ dir

2006-06-28T00:32:39Z

Fix kernel-doc parameters in kernel/ Warning(/var/linsrc/linux-2617-g9//kernel/auditsc.c:1376): No description found for parameter 'u_abs_timeout' Warning(/var/linsrc/linux-2617-g9//kernel/auditsc.c:1420): No description found for parameter 'u_msg_prio' Warning(/var/linsrc/linux-2617-g9//kernel/auditsc.c:1420): No description found for parameter 'u_abs_timeout' Warning(/var/linsrc/linux-2617-g9//kernel/acct.c:526): No description found for parameter 'pacct' Signed-off-by: Randy Dunlap Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] kernel/acct: fix function definition

2006-06-28T00:32:35Z

kernel/acct.c:579:19: warning: non-ANSI function declaration of function 'acct_process' Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] pacct: none-delayed process accounting accumulation

2006-06-25T17:01:25Z

In current 2.6.17 implementation, signal_struct refered from task_struct is used for per-process data structure. The pacct facility also uses it as a per-process data structure to store stime, utime, minflt, majflt. But those members are saved in __exit_signal(). It's too late. For example, if some threads exits at same time, pacct facility has a possibility to drop accountings for a part of those threads. (see, the following 'The results of original 2.6.17 kernel') I think accounting information should be completely collected into the per-process data structure before writing out an accounting record. This patch fixes this matter. Accumulation of stime, utime, minflt and majflt are done before generating accounting record. [mingo@elte.hu: fix acct_collect() siglock bug found by lockdep] Signed-off-by: KaiGai Kohei Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] pacct: avoidance to refer the last thread as a representation of the process

2006-06-25T17:01:25Z

When pacct facility generate an 'ac_flag' field in accounting record, it refers a task_struct of the thread which died last in the process. But any other task_structs are ignored. Therefore, pacct facility drops ASU flag even if root-privilege operations are used by any other threads except the last one. In addition, AFORK flag is always set when the thread of group-leader didn't die last, although this process has called execve() after fork(). We have a same matter in ac_exitcode. The recorded ac_exitcode is an exit code of the last thread in the process. There is a possibility this exitcode is not the group leader's one.

[PATCH] pacct: add pacct_struct to fix some pacct bugs.

2006-06-25T17:01:25Z

The pacct facility need an i/o operation when an accounting record is generated. There is a possibility to wake OOM killer up. If OOM killer is activated, it kills some processes to make them release process memory regions. But acct_process() is called in the killed processes context before calling exit_mm(), so those processes cannot release own memory. In the results, any processes stop in this point and it finally cause a system stall.

[PATCH] Remove unecessary NULL check in kernel/acct.c

2006-06-25T17:01:09Z

copy_process() appears to be the only caller of acct_clear_integrals() and does not pass in NULL task pointers. Remove the unecessary check. Signed-off-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry

2006-06-23T14:42:45Z

Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells Acked-by: Al Viro Cc: Nathan Scott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix pacct bug in multithreading case.

2006-03-31T20:18:54Z

I noticed a bug on the process accounting facility. In multi-threading process, some data would be recorded incorrectly when the group_leader dies earlier than one or more threads. The attached patch fixes this problem. See below. 'bugacct' is a test program that create a worker thread after 4 seconds sleeping, then the group_leader dies soon. The worker thread consume CPU/Memory for 6 seconds, then exit. We can estimate 10 seconds as etime and 6 seconds as stime + utime. This is a sample program which the group_leader dies earlier than other threads. The results of same binary execution on different kernel are below. -- accounted records -------------------- | btime | utime | stime | etime | minflt | majflt | comm | original | 13:16:40 | 0.00 | 0.00 | 6.10 | 171 | 0 | bugacct | patched | 13:20:21 | 5.83 | 0.18 | 10.03 | 32776 | 0 | bugacct | (*) bugacct allocates 128MB memory, thus 128MB / 4KB = 32768 of minflt is appropriate. -- Test results in original kernel ------ $ date; time -p ./bugacct Tue Mar 28 13:16:36 JST 2006 <- But pacct said btime is 13:16:40 real 10.11 <- But pacct said etime is 6.10 user 5.96 <- But pacct said utime is 0.00 sys 0.14 <- But pacct said stime is 0.00 $ -- Test results in patched kernel ------- $ date; time -p ./bugacct Tue Mar 28 13:20:21 JST 2006 real 10.04 user 5.83 sys 0.19 $ In the original 2.6.16 kernel, pacct records btime, utime, stime, etime and minflt incorrectly. In my opinion, this problem is caused by an assumption that group_leader dies last. The following section calculates process running time for etime and btime. But it means running time of the thread that dies last, not process. The start_time of the first thread in the process (group_leader) should be reduced from uptime to calculate etime and btime correctly. ---- do_acct_process() in kernel/acct.c: /* calculate run_time in nsec*/ do_posix_clock_monotonic_gettime(&uptime); run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec; run_time -= (u64)current->start_time.tv_sec*NSEC_PER_SEC + current->start_time.tv_nsec; ---- The following section calculates stime and utime of the process. But it might count the utime and stime of the group_leader duplicatly and ignore the utime and stime of the thread dies last, when one or more threads remain after group_leader dead. The ac_utime should be calculated as the sum of the signal->utime and utime of the thread dies last. The ac_stime should be done also. ---- do_acct_process() in kernel/acct.c: jiffies = cputime_to_jiffies(cputime_add(current->group_leader->utime, current->signal->utime)); ac.ac_utime = encode_comp_t(jiffies_to_AHZ(jiffies)); jiffies = cputime_to_jiffies(cputime_add(current->group_leader->stime, current->signal->stime)); ac.ac_stime = encode_comp_t(jiffies_to_AHZ(jiffies)); ---- The part of the minflt/majflt calculation has same problem. This patch solves those problems, I think. Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds