From 0e0af57e0e91b304f36b7d1dba859e3c04094273 Mon Sep 17 00:00:00 2001 From: "Dr. Thomas Orgis" Date: Fri, 29 Apr 2022 14:38:03 -0700 Subject: taskstats: version 12 with thread group and exe info The task exit struct needs some crucial information to be able to provide an enhanced version of process and thread accounting. This change provides: 1. ac_tgid in additon to ac_pid 2. thread group execution walltime in ac_tgetime 3. flag AGROUP in ac_flag to indicate the last task in a thread group / process 4. device ID and inode of task's /proc/self/exe in ac_exe_dev and ac_exe_inode 5. tools/accounting/procacct as demonstrator When a task exits, taskstats are reported to userspace including the task's pid and ppid, but without the id of the thread group this task is part of. Without the tgid, the stats of single tasks cannot be correlated to each other as a thread group (process). The taskstats documentation suggests that on process exit a data set consisting of accumulated stats for the whole group is produced. But such an additional set of stats is only produced for actually multithreaded processes, not groups that had only one thread, and also those stats only contain data about delay accounting and not the more basic information about CPU and memory resource usage. Adding the AGROUP flag to be set when the last task of a group exited enables determination of process end also for single-threaded processes. My applicaton basically does enhanced process accounting with summed cputime, biggest maxrss, tasks per process. The data is not available with the traditional BSD process accounting (which is not designed to be extensible) and the taskstats interface allows more efficient on-the-fly grouping and summing of the stats, anyway, without intermediate disk writes. Furthermore, I do carry statistics on which exact program binary is used how often with associated resources, getting a picture on how important which parts of a collection of installed scientific software in different versions are, and how well they put load on the machine. This is enabled by providing information on /proc/self/exe for each task. I assume the two 64-bit fields for device ID and inode are more appropriate than the possibly large resolved path to keep the data volume down. Add the tgid to the stats to complete task identification, the flag AGROUP to mark the last task of a group, the group wallclock time, and inode-based identification of the associated executable file. Add tools/accounting/procacct.c as a simplified fork of getdelays.c to demonstrate process and thread accounting. [thomas.orgis@uni-hamburg.de: fix version number in comment] Link: https://lkml.kernel.org/r/20220405003601.7a5f6008@plasteblaster Link: https://lkml.kernel.org/r/20220331004106.64e5616b@plasteblaster Signed-off-by: Dr. Thomas Orgis Reviewed-by: Ismael Luceno Cc: Balbir Singh Cc: Eric W. Biederman Cc: xu xin Cc: Yang Yang Signed-off-by: Andrew Morton --- include/uapi/linux/acct.h | 3 ++- include/uapi/linux/taskstats.h | 24 +++++++++++++++++++++--- 2 files changed, 23 insertions(+), 4 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/acct.h b/include/uapi/linux/acct.h index 985b89068591..0e591152aa8a 100644 --- a/include/uapi/linux/acct.h +++ b/include/uapi/linux/acct.h @@ -103,12 +103,13 @@ struct acct_v3 /* * accounting flags */ - /* bit set when the process ... */ + /* bit set when the process/task ... */ #define AFORK 0x01 /* ... executed fork, but did not exec */ #define ASU 0x02 /* ... used super-user privileges */ #define ACOMPAT 0x04 /* ... used compatibility mode (VAX only not used) */ #define ACORE 0x08 /* ... dumped core */ #define AXSIG 0x10 /* ... was killed by a signal */ +#define AGROUP 0x20 /* ... was the last task of the process (task group) */ #if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN) #define ACCT_BYTEORDER 0x80 /* accounting file is big endian */ diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h index 12327d32378f..736154171489 100644 --- a/include/uapi/linux/taskstats.h +++ b/include/uapi/linux/taskstats.h @@ -34,7 +34,7 @@ */ -#define TASKSTATS_VERSION 11 +#define TASKSTATS_VERSION 12 #define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN * in linux/sched.h */ @@ -48,7 +48,8 @@ struct taskstats { __u32 ac_exitcode; /* Exit status */ /* The accounting flags of a task as defined in - * Defined values are AFORK, ASU, ACOMPAT, ACORE, and AXSIG. + * Defined values are AFORK, ASU, ACOMPAT, ACORE, AXSIG, and AGROUP. + * (AGROUP since version 12). */ __u8 ac_flag; /* Record flags */ __u8 ac_nice; /* task_nice */ @@ -173,9 +174,26 @@ struct taskstats { /* v10: 64-bit btime to avoid overflow */ __u64 ac_btime64; /* 64-bit begin time */ - /* Delay waiting for memory compact */ + /* v11: Delay waiting for memory compact */ __u64 compact_count; __u64 compact_delay_total; + + /* v12 begin */ + __u32 ac_tgid; /* thread group ID */ + /* Thread group walltime up to now. This is total process walltime if + * AGROUP flag is set. + */ + __u64 ac_tgetime __attribute__((aligned(8))); + /* Lightweight information to identify process binary files. + * This leaves userspace to match this to a file system path, using + * MAJOR() and MINOR() macros to identify a device and mount point, + * the inode to identify the executable file. This is /proc/self/exe + * at the end, so matching the most recent exec(). Values are zero + * for kernel threads. + */ + __u64 ac_exe_dev; /* program binary device ID */ + __u64 ac_exe_inode; /* program binary inode number */ + /* v12 end */ }; -- cgit v1.2.3-59-g8ed1b From c9b516f16be5896a3d798f8efb03acbd2ceec715 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Thu, 12 May 2022 20:38:36 -0700 Subject: ELF, uapi: fixup ELF_ST_TYPE definition This is very theoretical compile failure: ELF_ST_TYPE(st_info = A) Cast will bind first and st_info will stop being lvalue: error: lvalue required as left operand of assignment Given that the only use of this macro is ELF_ST_TYPE(sym->st_info) where st_info is "unsigned char" I've decided to remove cast especially given that companion macro ELF_ST_BIND doesn't use cast. Link: https://lkml.kernel.org/r/Ymv7G1BeX4kt3obz@localhost.localdomain Signed-off-by: Alexey Dobriyan Acked-by: Kees Cook Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton --- include/uapi/linux/elf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 787c657bfae8..237f21a5e0f6 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -134,7 +134,7 @@ typedef __s64 Elf64_Sxword; #define STT_TLS 6 #define ELF_ST_BIND(x) ((x) >> 4) -#define ELF_ST_TYPE(x) (((unsigned int) x) & 0xf) +#define ELF_ST_TYPE(x) ((x) & 0xf) #define ELF32_ST_BIND(x) ELF_ST_BIND(x) #define ELF32_ST_TYPE(x) ELF_ST_TYPE(x) #define ELF64_ST_BIND(x) ELF_ST_BIND(x) -- cgit v1.2.3-59-g8ed1b