[Crash-utility] [PATCH] speed up "ps -r" by storing the length of rlim array
Without this patch, the "ps -r" command takes one minute or more per 1,000
tasks. The cause is that getting the length of {task,signal}_struct.rlim
array takes some time and it is done for each task.
This patch stores the value, and it will take only about 0.5 seconds per
1,000 tasks.
Signed-off-by: Kazuhito Hagio <k-hagio(a)ab.jp.nec.com>
---
defs.h | 2 ++
symbols.c | 8 ++++++++
task.c | 6 ++++--
3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/defs.h b/defs.h
index adddb9f..4b6ebc2 100644
--- a/defs.h
+++ b/defs.h
@@ -2191,6 +2191,8 @@ struct array_table {
int kmem_cache_cpu_slab;
int rt_prio_array_queue;
int height_to_maxnodes;
+ int task_struct_rlim;
+ int signal_struct_rlim;
};
/*
diff --git a/symbols.c b/symbols.c
index 638800a..e934e7f 100644
--- a/symbols.c
+++ b/symbols.c
@@ -8440,6 +8440,10 @@ builtin_array_length(char *s, int len, int *two_dim)
lenptr = &array_table.kmem_cache_cpu_slab;
else if (STREQ(s, "rt_prio_array.queue"))
lenptr = &array_table.rt_prio_array_queue;
+ else if (STREQ(s, "task_struct.rlim"))
+ lenptr = &array_table.task_struct_rlim;
+ else if (STREQ(s, "signal_struct.rlim"))
+ lenptr = &array_table.signal_struct_rlim;
if (!lenptr) /* not stored */
return(len);
@@ -10520,6 +10524,10 @@ dump_offset_table(char *spec, ulong makestruct)
ARRAY_LENGTH(kmem_cache_cpu_slab));
fprintf(fp, " rt_prio_array_queue: %d\n",
ARRAY_LENGTH(rt_prio_array_queue));
+ fprintf(fp, " task_struct_rlim: %d\n",
+ ARRAY_LENGTH(task_struct_rlim));
+ fprintf(fp, " signal_struct_rlim: %d\n",
+ ARRAY_LENGTH(signal_struct_rlim));
if (spec) {
int in_size_table, in_array_table, arrays, offsets, sizes;
diff --git a/task.c b/task.c
index 560adfa..2418e4c 100644
--- a/task.c
+++ b/task.c
@@ -4027,12 +4027,14 @@ show_task_rlimit(struct task_context *tc)
in_task_struct = in_signal_struct = FALSE;
if (VALID_MEMBER(task_struct_rlim)) {
- rlimit_index = get_array_length("task_struct.rlim", NULL, 0);
+ rlimit_index = (i = ARRAY_LENGTH(task_struct_rlim)) ?
+ i : get_array_length("task_struct.rlim", NULL, 0);
in_task_struct = TRUE;
} else if (VALID_MEMBER(signal_struct_rlim)) {
if (!VALID_MEMBER(task_struct_signal))
error(FATAL, "cannot determine rlimit array location\n");
- rlimit_index = get_array_length("signal_struct.rlim", NULL, 0);
+ rlimit_index = (i = ARRAY_LENGTH(signal_struct_rlim)) ?
+ i : get_array_length("signal_struct.rlim", NULL, 0);
in_signal_struct = TRUE;
}
--
1.8.3.1