Re: [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 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