Currently, crash doesn't support to display disk I/O statistics
for blk-mq devices. For more details, please refer to the commit
98b417fc6346 ("Handle blk_mq_ctx member changes for kernels 5.16-rc1
and later").
Lets parse the bitmap in blk-mq layer to achieve it.
Signed-off-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
---
defs.h | 11 +++
dev.c | 244 +++++++++++++++++++++++++++++++++++++++++++++---------
symbols.c | 22 +++++
3 files changed, 238 insertions(+), 39 deletions(-)
diff --git a/defs.h b/defs.h
index c8444b4e54eb..2681586a33dc 100644
--- a/defs.h
+++ b/defs.h
@@ -2170,6 +2170,16 @@ struct offset_table { /* stash of commonly-used offsets */
long sbq_wait_state_wait;
long sbitmap_alloc_hint;
long sbitmap_round_robin;
+ long request_cmd_flags;
+ long request_q;
+ long request_state;
+ long request_queue_queue_hw_ctx;
+ long request_queue_nr_hw_queues;
+ long blk_mq_hw_ctx_tags;
+ long blk_mq_tags_bitmap_tags;
+ long blk_mq_tags_breserved_tags;
+ long blk_mq_tags_nr_reserved_tags;
+ long blk_mq_tags_rqs;
};
struct size_table { /* stash of commonly-used sizes */
@@ -2339,6 +2349,7 @@ struct size_table { /* stash of commonly-used sizes */
long sbitmap;
long sbitmap_queue;
long sbq_wait_state;
+ long blk_mq_tags;
};
struct array_table {
diff --git a/dev.c b/dev.c
index a493e51ac95c..4be4c96df8b0 100644
--- a/dev.c
+++ b/dev.c
@@ -4238,19 +4238,176 @@ get_one_mctx_diskio(unsigned long mctx, struct diskio *io)
io->write = (dispatch[1] - comp[1]);
}
+typedef bool (busy_tag_iter_fn)(ulong rq, void *data);
+
+struct mq_inflight {
+ ulong q;
+ struct diskio *dio;
+};
+
+struct bt_iter_data {
+ ulong tags;
+ uint reserved;
+ uint nr_reserved_tags;
+ busy_tag_iter_fn *fn;
+ void *data;
+};
+
+/*
+ * See the include/linux/blk_types.h and include/linux/blk-mq.h
+ */
+#define MQ_RQ_IN_FLIGHT 1
+#define REQ_OP_BITS 8
+#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
+
+static uint op_is_write(uint op)
+{
+ return (op & REQ_OP_MASK) & 1;
+}
+
+static bool mq_check_inflight(ulong rq, void *data)
+{
+ uint cmd_flags = 0, state = 0;
+ ulong addr = 0, queue = 0;
+ struct mq_inflight *mi = data;
+
+ if (!IS_KVADDR(rq))
+ return TRUE;
+
+ addr = rq + OFFSET(request_q);
+ if (!readmem(addr, KVADDR, &queue, sizeof(ulong), "request.q", RETURN_ON_ERROR))
+ return FALSE;
+
+ addr = rq + OFFSET(request_cmd_flags);
+ if (!readmem(addr, KVADDR, &cmd_flags, sizeof(uint), "request.cmd_flags", RETURN_ON_ERROR))
+ return FALSE;
+
+ addr = rq + OFFSET(request_state);
+ if (!readmem(addr, KVADDR, &state, sizeof(uint), "request.state", RETURN_ON_ERROR))
+ return FALSE;
+
+ if (queue == mi->q && state == MQ_RQ_IN_FLIGHT) {
+ if (op_is_write(cmd_flags))
+ mi->dio->write++;
+ else
+ mi->dio->read++;
+ }
+
+ return TRUE;
+}
+
+static bool bt_iter(uint bitnr, void *data)
+{
+ ulong addr = 0, rqs_addr = 0, rq = 0;
+ struct bt_iter_data *iter_data = data;
+ ulong tag = iter_data->tags;
+
+ if (!iter_data->reserved)
+ bitnr += iter_data->nr_reserved_tags;
+
+ /* rqs */
+ addr = tag + OFFSET(blk_mq_tags_rqs);
+ if (!readmem(addr, KVADDR, &rqs_addr, sizeof(void *), "blk_mq_tags.rqs", RETURN_ON_ERROR))
+ return FALSE;
+
+ addr = rqs_addr + bitnr * sizeof(ulong); /* rqs[bitnr] */
+ if (!readmem(addr, KVADDR, &rq, sizeof(ulong), "blk_mq_tags.rqs[]", RETURN_ON_ERROR))
+ return FALSE;
+
+ return iter_data->fn(rq, iter_data->data);
+}
+
+static void bt_for_each(ulong q, ulong tags, ulong sbq, uint reserved, uint nr_resvd_tags, struct diskio *dio)
+{
+ struct sbitmap_context sc = {0};
+ struct mq_inflight mi = {
+ .q = q,
+ .dio = dio,
+ };
+ struct bt_iter_data iter_data = {
+ .tags = tags,
+ .reserved = reserved,
+ .nr_reserved_tags = nr_resvd_tags,
+ .fn = mq_check_inflight,
+ .data = &mi,
+ };
+
+ sbitmap_context_load(sbq + OFFSET(sbitmap_queue_sb), &sc);
+ sbitmap_for_each_set(&sc, bt_iter, &iter_data);
+}
+
+static void queue_for_each_hw_ctx(ulong q, ulong *hctx, uint cnt, struct diskio *dio)
+{
+ uint i;
+
+ for (i = 0; i < cnt; i++) {
+ ulong addr = 0, tags = 0;
+ uint nr_reserved_tags = 0;
+
+ /* Tags owned by the block driver */
+ addr = hctx[i] + OFFSET(blk_mq_hw_ctx_tags);
+ if (!readmem(addr, KVADDR, &tags, sizeof(ulong),
+ "blk_mq_hw_ctx.tags", RETURN_ON_ERROR))
+ break;
+
+ addr = tags + OFFSET(blk_mq_tags_nr_reserved_tags);
+ if (!readmem(addr, KVADDR, &nr_reserved_tags, sizeof(uint),
+ "blk_mq_tags_nr_reserved_tags", RETURN_ON_ERROR))
+ break;
+
+ if (nr_reserved_tags) {
+ addr = tags + OFFSET(blk_mq_tags_breserved_tags);
+ bt_for_each(q, tags, addr, 1, nr_reserved_tags, dio);
+ }
+ addr = tags + OFFSET(blk_mq_tags_bitmap_tags);
+ bt_for_each(q, tags, addr, 0, nr_reserved_tags, dio);
+ }
+}
+
+static void get_mq_diskio_from_hw_queues(ulong q, struct diskio *dio)
+{
+ uint cnt = 0;
+ ulong addr = 0, hctx_addr = 0;
+ ulong *hctx_array = NULL;
+
+ addr = q + OFFSET(request_queue_nr_hw_queues);
+ readmem(addr, KVADDR, &cnt, sizeof(uint),
+ "request_queue.nr_hw_queues", FAULT_ON_ERROR);
+
+ addr = q + OFFSET(request_queue_queue_hw_ctx);
+ readmem(addr, KVADDR, &hctx_addr, sizeof(void *),
+ "request_queue.queue_hw_ctx", FAULT_ON_ERROR);
+
+ hctx_array = (ulong *)GETBUF(sizeof(void *) * cnt);
+ if (!hctx_array)
+ error(FATAL, "fail to get memory for the hctx_array\n");
+
+ if (!readmem(hctx_addr, KVADDR, hctx_array, sizeof(void *) * cnt,
+ "request_queue.queue_hw_ctx[]", RETURN_ON_ERROR)) {
+ FREEBUF(hctx_array);
+ return;
+ }
+
+ queue_for_each_hw_ctx(q, hctx_array, cnt, dio);
+
+ FREEBUF(hctx_array);
+}
+
static void
get_mq_diskio(unsigned long q, unsigned long *mq_count)
{
int cpu;
unsigned long queue_ctx;
unsigned long mctx_addr;
- struct diskio tmp;
+ struct diskio tmp = {0};
if (INVALID_MEMBER(blk_mq_ctx_rq_dispatched) ||
- INVALID_MEMBER(blk_mq_ctx_rq_completed))
+ INVALID_MEMBER(blk_mq_ctx_rq_completed)) {
+ get_mq_diskio_from_hw_queues(q, &tmp);
+ mq_count[0] = tmp.read;
+ mq_count[1] = tmp.write;
return;
-
- memset(&tmp, 0x00, sizeof(struct diskio));
+ }
readmem(q + OFFSET(request_queue_queue_ctx), KVADDR, &queue_ctx,
sizeof(ulong), "request_queue.queue_ctx",
@@ -4479,41 +4636,24 @@ display_one_diskio(struct iter *i, unsigned long gendisk, ulong flags)
&& (io.read + io.write == 0))
return;
- if (use_mq_interface(queue_addr) &&
- (INVALID_MEMBER(blk_mq_ctx_rq_dispatched) ||
- INVALID_MEMBER(blk_mq_ctx_rq_completed)))
- fprintf(fp, "%s%s%s %s%s%s%s %s%s%s",
- mkstring(buf0, 5, RJUST|INT_DEC, (char *)(unsigned long)major),
- space(MINSPACE),
- mkstring(buf1, VADDR_PRLEN, LJUST|LONG_HEX, (char *)gendisk),
- space(MINSPACE),
- mkstring(buf2, 10, LJUST, disk_name),
- space(MINSPACE),
- mkstring(buf3, VADDR_PRLEN <= 11 ? 11 : VADDR_PRLEN,
- LJUST|LONG_HEX, (char *)queue_addr),
- space(MINSPACE),
- mkstring(buf4, 17, RJUST, "(not supported)"),
- space(MINSPACE));
-
- else
- fprintf(fp, "%s%s%s %s%s%s%s %s%5d%s%s%s%s%s",
- mkstring(buf0, 5, RJUST|INT_DEC, (char *)(unsigned long)major),
- space(MINSPACE),
- mkstring(buf1, VADDR_PRLEN, LJUST|LONG_HEX, (char *)gendisk),
- space(MINSPACE),
- mkstring(buf2, 10, LJUST, disk_name),
- space(MINSPACE),
- mkstring(buf3, VADDR_PRLEN <= 11 ? 11 : VADDR_PRLEN,
- LJUST|LONG_HEX, (char *)queue_addr),
- space(MINSPACE),
- io.read + io.write,
- space(MINSPACE),
- mkstring(buf4, 5, RJUST|INT_DEC,
- (char *)(unsigned long)io.read),
- space(MINSPACE),
- mkstring(buf5, 5, RJUST|INT_DEC,
- (char *)(unsigned long)io.write),
- space(MINSPACE));
+ fprintf(fp, "%s%s%s %s%s%s%s %s%5d%s%s%s%s%s",
+ mkstring(buf0, 5, RJUST|INT_DEC, (char *)(unsigned long)major),
+ space(MINSPACE),
+ mkstring(buf1, VADDR_PRLEN, LJUST|LONG_HEX, (char *)gendisk),
+ space(MINSPACE),
+ mkstring(buf2, 10, LJUST, disk_name),
+ space(MINSPACE),
+ mkstring(buf3, VADDR_PRLEN <= 11 ? 11 : VADDR_PRLEN,
+ LJUST|LONG_HEX, (char *)queue_addr),
+ space(MINSPACE),
+ io.read + io.write,
+ space(MINSPACE),
+ mkstring(buf4, 5, RJUST|INT_DEC,
+ (char *)(unsigned long)io.read),
+ space(MINSPACE),
+ mkstring(buf5, 5, RJUST|INT_DEC,
+ (char *)(unsigned long)io.write),
+ space(MINSPACE));
if (VALID_MEMBER(request_queue_in_flight)) {
if (!use_mq_interface(queue_addr)) {
@@ -4597,6 +4737,9 @@ void diskio_init(void)
MEMBER_OFFSET_INIT(kobject_entry, "kobject", "entry");
MEMBER_OFFSET_INIT(kset_list, "kset", "list");
MEMBER_OFFSET_INIT(request_list_count, "request_list", "count");
+ MEMBER_OFFSET_INIT(request_cmd_flags, "request", "cmd_flags");
+ MEMBER_OFFSET_INIT(request_q, "request", "q");
+ MEMBER_OFFSET_INIT(request_state, "request", "state");
MEMBER_OFFSET_INIT(request_queue_in_flight, "request_queue",
"in_flight");
if (MEMBER_EXISTS("request_queue", "rq"))
@@ -4608,10 +4751,33 @@ void diskio_init(void)
"mq_ops");
ANON_MEMBER_OFFSET_INIT(request_queue_queue_ctx,
"request_queue", "queue_ctx");
+ MEMBER_OFFSET_INIT(request_queue_queue_hw_ctx,
+ "request_queue", "queue_hw_ctx");
+ MEMBER_OFFSET_INIT(request_queue_nr_hw_queues,
+ "request_queue", "nr_hw_queues");
MEMBER_OFFSET_INIT(blk_mq_ctx_rq_dispatched, "blk_mq_ctx",
"rq_dispatched");
MEMBER_OFFSET_INIT(blk_mq_ctx_rq_completed, "blk_mq_ctx",
"rq_completed");
+ MEMBER_OFFSET_INIT(blk_mq_hw_ctx_tags, "blk_mq_hw_ctx", "tags");
+ MEMBER_OFFSET_INIT(blk_mq_tags_bitmap_tags, "blk_mq_tags",
+ "bitmap_tags");
+ MEMBER_OFFSET_INIT(blk_mq_tags_breserved_tags, "blk_mq_tags",
+ "breserved_tags");
+ MEMBER_OFFSET_INIT(blk_mq_tags_nr_reserved_tags, "blk_mq_tags",
+ "nr_reserved_tags");
+ MEMBER_OFFSET_INIT(blk_mq_tags_rqs, "blk_mq_tags", "rqs");
+ STRUCT_SIZE_INIT(blk_mq_tags, "blk_mq_tags");
+ STRUCT_SIZE_INIT(sbitmap, "sbitmap");
+ STRUCT_SIZE_INIT(sbitmap_word, "sbitmap_word");
+ MEMBER_OFFSET_INIT(sbitmap_word_word, "sbitmap_word", "word");
+ MEMBER_OFFSET_INIT(sbitmap_word_cleared, "sbitmap_word", "cleared");
+ MEMBER_OFFSET_INIT(sbitmap_depth, "sbitmap", "depth");
+ MEMBER_OFFSET_INIT(sbitmap_shift, "sbitmap", "shift");
+ MEMBER_OFFSET_INIT(sbitmap_map_nr, "sbitmap", "map_nr");
+ MEMBER_OFFSET_INIT(sbitmap_map, "sbitmap", "map");
+ MEMBER_OFFSET_INIT(sbitmap_queue_sb, "sbitmap_queue", "sb");
+
}
MEMBER_OFFSET_INIT(subsys_private_klist_devices, "subsys_private",
"klist_devices");
diff --git a/symbols.c b/symbols.c
index 5d12a021c769..c1f09556d710 100644
--- a/symbols.c
+++ b/symbols.c
@@ -10385,6 +10385,12 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(kset_list));
fprintf(fp, " request_list_count: %ld\n",
OFFSET(request_list_count));
+ fprintf(fp, " request_cmd_flags: %ld\n",
+ OFFSET(request_cmd_flags));
+ fprintf(fp, " request_q: %ld\n",
+ OFFSET(request_q));
+ fprintf(fp, " request_state: %ld\n",
+ OFFSET(request_state));
fprintf(fp, " request_queue_in_flight: %ld\n",
OFFSET(request_queue_in_flight));
fprintf(fp, " request_queue_rq: %ld\n",
@@ -10393,10 +10399,25 @@ dump_offset_table(char *spec, ulong makestruct)
OFFSET(request_queue_mq_ops));
fprintf(fp, " request_queue_queue_ctx: %ld\n",
OFFSET(request_queue_queue_ctx));
+ fprintf(fp, " request_queue_queue_hw_ctx: %ld\n",
+ OFFSET(request_queue_queue_hw_ctx));
+ fprintf(fp, " request_queue_nr_hw_queues: %ld\n",
+ OFFSET(request_queue_nr_hw_queues));
fprintf(fp, " blk_mq_ctx_rq_dispatched: %ld\n",
OFFSET(blk_mq_ctx_rq_dispatched));
fprintf(fp, " blk_mq_ctx_rq_completed: %ld\n",
OFFSET(blk_mq_ctx_rq_completed));
+ fprintf(fp, " blk_mq_hw_ctx_tags: %ld\n",
+ OFFSET(blk_mq_hw_ctx_tags));
+ fprintf(fp, " blk_mq_tags_bitmap_tags: %ld\n",
+ OFFSET(blk_mq_tags_bitmap_tags));
+ fprintf(fp, " blk_mq_tags_breserved_tags: %ld\n",
+ OFFSET(blk_mq_tags_breserved_tags));
+ fprintf(fp, " blk_mq_tags_nr_reserved_tags: %ld\n",
+ OFFSET(blk_mq_tags_nr_reserved_tags));
+ fprintf(fp, " blk_mq_tags_rqs: %ld\n",
+ OFFSET(blk_mq_tags_rqs));
+
fprintf(fp, " subsys_private_klist_devices: %ld\n",
OFFSET(subsys_private_klist_devices));
fprintf(fp, " subsystem_kset: %ld\n",
@@ -11003,6 +11024,7 @@ dump_offset_table(char *spec, ulong makestruct)
fprintf(fp, " sbitmap: %ld\n", SIZE(sbitmap));
fprintf(fp, " sbitmap_queue: %ld\n", SIZE(sbitmap_queue));
fprintf(fp, " sbq_wait_state: %ld\n", SIZE(sbq_wait_state));
+ fprintf(fp, " blk_mq_tags: %ld\n", SIZE(blk_mq_tags));
fprintf(fp, "\n array_table:\n");
/*
--
2.20.1
--
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