Re: [Crash-utility] [PATCH v2] Fix for mm_struct.rss_stat conversion into percpu_counter

Date: Thu, 15 Dec 2022 02:31:38 +0000 From: HAGIO KAZUHITO(?????) <k-hagio-ab(a)nec.com&gt; To: &quot;crash-utility(a)redhat.com&quot; <crash-utility(a)redhat.com&gt; Subject: [Crash-utility] [PATCH v2] Fix for mm_struct.rss_stat conversion into percpu_counter Message-ID: <1671071492-12338-1-git-send-email-k-hagio-ab(a)nec.com&gt; Content-Type: text/plain; charset="iso-2022-jp" Kernel commit f1a7941243c1 ("mm: convert mm's rss stats into percpu_counter"), which is contained in Linux 6.2-rc1 and later kernels, changed mm_struct.rss_stat from struct mm_rss_stat into an array of struct percpu_counter. Without the patch, "ps" and several commands fail with the following error message: ps: invalid structure member offset: mm_rss_stat_count FILE: memory.c LINE: 4724 FUNCTION: get_task_mem_usage() Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- v1 -> v2 - Fix broken indent - Update commit log Hi Lianbo, I've updated the patch as the kernel patch is merged into the mainline. And the indent issue is fixed with this patch?

defs.h | 3 +++ kernel.c | 2 ++ memory.c | 14 +++++++++++++- symbols.c | 6 ++++-- tools.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/defs.h b/defs.h index afdcf6c4ac20..005b79cf9e74 100644 --- a/defs.h +++ b/defs.h @@ -2181,6 +2181,7 @@ struct offset_table { /* stash of commonly-used offsets */ long blk_mq_tags_nr_reserved_tags; long blk_mq_tags_rqs; long request_queue_hctx_table; + long percpu_counter_counters; }; struct size_table { /* stash of commonly-used sizes */ @@ -2351,6 +2352,7 @@ struct size_table { /* stash of commonly-used sizes */ long sbitmap_queue; long sbq_wait_state; long blk_mq_tags; + long percpu_counter; }; struct array_table { @@ -5305,6 +5307,7 @@ struct rb_node *rb_right(struct rb_node *, struct rb_node *); struct rb_node *rb_left(struct rb_node *, struct rb_node *); struct rb_node *rb_next(struct rb_node *); struct rb_node *rb_last(struct rb_root *); +long percpu_counter_sum_positive(ulong fbc); /* * symbols.c diff --git a/kernel.c b/kernel.c index aa030e8097ea..a42e6ad7d78c 100644 --- a/kernel.c +++ b/kernel.c @@ -316,6 +316,8 @@ kernel_init() } MEMBER_OFFSET_INIT(percpu_counter_count, "percpu_counter", "count"); + MEMBER_OFFSET_INIT(percpu_counter_counters, "percpu_counter", "counters"); + STRUCT_SIZE_INIT(percpu_counter, "percpu_counter"); if (STRUCT_EXISTS("runqueue")) { rqstruct = "runqueue"; diff --git a/memory.c b/memory.c index 9c15c1b745ef..dc658bc14c33 100644 --- a/memory.c +++ b/memory.c @@ -4713,7 +4713,7 @@ 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)) { + if (VALID_MEMBER(mm_struct_rss_stat) && VALID_MEMBER(mm_rss_stat_count)) { long anonpages, filepages, count; anonpages = tt->anonpages; @@ -4737,6 +4737,18 @@ get_task_mem_usage(ulong task, struct task_mem_usage *tm) (anonpages * sizeof(long))); if (count > 0) rss += count; + + } else if (VALID_MEMBER(mm_struct_rss_stat)) { + /* Linux v6.2: struct percpu_counter rss_stat[NR_MM_COUNTERS] */ + ulong fbc; + + fbc = tc->mm_struct + OFFSET(mm_struct_rss_stat) + + (tt->filepages * SIZE(percpu_counter)); + rss += percpu_counter_sum_positive(fbc); + + fbc = tc->mm_struct + OFFSET(mm_struct_rss_stat) + + (tt->anonpages * SIZE(percpu_counter)); + rss += percpu_counter_sum_positive(fbc); } /* Check whether SPLIT_RSS_COUNTING is enabled */ diff --git a/symbols.c b/symbols.c index 42c4eb400044..e279cfa68490 100644 --- a/symbols.c +++ b/symbols.c @@ -10633,8 +10633,8 @@ dump_offset_table(char *spec, ulong makestruct) OFFSET(ktime_t_nsec)); fprintf(fp, " atomic_t_counter: %ld\n", OFFSET(atomic_t_counter)); - fprintf(fp, " percpu_counter_count: %ld\n", - OFFSET(percpu_counter_count)); + fprintf(fp, " percpu_counter_count: %ld\n", OFFSET(percpu_counter_count)); + fprintf(fp, " percpu_counter_counters: %ld\n", OFFSET(percpu_counter_counters)); fprintf(fp, " sk_buff_head_next: %ld\n", OFFSET(sk_buff_head_next)); fprintf(fp, " sk_buff_head_qlen: %ld\n", @@ -11028,6 +11028,8 @@ dump_offset_table(char *spec, ulong makestruct) fprintf(fp, " sbq_wait_state: %ld\n", SIZE(sbq_wait_state)); fprintf(fp, " blk_mq_tags: %ld\n", SIZE(blk_mq_tags)); + fprintf(fp, " percpu_counter: %ld\n", SIZE(percpu_counter)); + fprintf(fp, "\n array_table:\n"); /* * Use get_array_length() for those fields not set up at init-time; diff --git a/tools.c b/tools.c index 39306c18c98f..5f86771f5327 100644 --- a/tools.c +++ b/tools.c @@ -6902,3 +6902,31 @@ rb_last(struct rb_root *root) return node; } + +long +percpu_counter_sum_positive(ulong fbc) +{ + int i, count; + ulong addr; + long ret; + + if (INVALID_MEMBER(percpu_counter_count)) + return 0; + + readmem(fbc + OFFSET(percpu_counter_count), KVADDR, &ret, + sizeof(long long), "percpu_counter.count", FAULT_ON_ERROR); + + if (INVALID_MEMBER(percpu_counter_counters)) /* !CONFIG_SMP */ + return (ret < 0) ? 0 : ret; + + readmem(fbc + OFFSET(percpu_counter_counters), KVADDR, &addr, + sizeof(void *), "percpu_counter.counters", FAULT_ON_ERROR); + + for (i = 0; i < kt->cpus; i++) { + readmem(addr + kt->__per_cpu_offset[i], KVADDR, &count, + sizeof(int), "percpu_counter.counters count", FAULT_ON_ERROR); + ret += count; + } + + return (ret < 0) ? 0 : ret; +} -- 2.31.1