87 lines
2.6 KiB
Diff
87 lines
2.6 KiB
Diff
From 74fe453f2b5ddf1e1571d006d486cb214817a0ed Mon Sep 17 00:00:00 2001
|
|
From: Lianbo Jiang <lijiang@redhat.com>
|
|
Date: Wed, 9 Nov 2022 14:21:57 +0800
|
|
Subject: [PATCH 28/28] Fix for "ps/vm" commands to display correct %MEM and
|
|
RSS values
|
|
|
|
The ps/vm commands may print the bogus value of the %MEM and RSS, the
|
|
reason is that the counter of rss stat is updated in asynchronous manner
|
|
and may become negative, when the SPLIT_RSS_COUNTING is enabled in kernel.
|
|
|
|
As a result, crash will read it from memory and convert from negative to
|
|
unsigned long integer, eventually it overflows and gets a big integer. For
|
|
example:
|
|
|
|
crash> ps 1393
|
|
PID PPID CPU TASK ST %MEM VSZ RSS COMM
|
|
1393 1 24 ffff9584bb542100 RU 541298032135.9 4132 18014398509481908 enlinuxpc64
|
|
^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^
|
|
|
|
This is unexpected, crash needs to correct its value for this case.
|
|
|
|
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
|
|
---
|
|
memory.c | 23 ++++++++++++++++++-----
|
|
1 file changed, 18 insertions(+), 5 deletions(-)
|
|
|
|
diff --git a/memory.c b/memory.c
|
|
index ddbf458277f0..2167281b6039 100644
|
|
--- a/memory.c
|
|
+++ b/memory.c
|
|
@@ -4714,18 +4714,29 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm)
|
|
* Latest kernels have mm_struct.mm_rss_stat[].
|
|
*/
|
|
if (VALID_MEMBER(mm_struct_rss_stat)) {
|
|
- long anonpages, filepages;
|
|
+ long anonpages, filepages, count;
|
|
|
|
anonpages = tt->anonpages;
|
|
filepages = tt->filepages;
|
|
- rss += LONG(tt->mm_struct +
|
|
+ count = LONG(tt->mm_struct +
|
|
OFFSET(mm_struct_rss_stat) +
|
|
OFFSET(mm_rss_stat_count) +
|
|
(filepages * sizeof(long)));
|
|
- rss += LONG(tt->mm_struct +
|
|
+
|
|
+ /*
|
|
+ * The counter is updated in asynchronous manner
|
|
+ * and may become negative, see:
|
|
+ * include/linux/mm.h: get_mm_counter()
|
|
+ */
|
|
+ if (count > 0)
|
|
+ rss += count;
|
|
+
|
|
+ count = LONG(tt->mm_struct +
|
|
OFFSET(mm_struct_rss_stat) +
|
|
OFFSET(mm_rss_stat_count) +
|
|
(anonpages * sizeof(long)));
|
|
+ if (count > 0)
|
|
+ rss += count;
|
|
}
|
|
|
|
/* Check whether SPLIT_RSS_COUNTING is enabled */
|
|
@@ -4769,7 +4780,8 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm)
|
|
RETURN_ON_ERROR))
|
|
continue;
|
|
|
|
- rss_cache += sync_rss;
|
|
+ if (sync_rss > 0)
|
|
+ rss_cache += sync_rss;
|
|
|
|
/* count 1 -> anonpages */
|
|
if (!readmem(first->task +
|
|
@@ -4782,7 +4794,8 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm)
|
|
RETURN_ON_ERROR))
|
|
continue;
|
|
|
|
- rss_cache += sync_rss;
|
|
+ if (sync_rss > 0)
|
|
+ rss_cache += sync_rss;
|
|
|
|
if (first == last)
|
|
break;
|
|
--
|
|
2.37.1
|
|
|