Re: [Crash-utility] [PATCH v2 1/2] Support for "dev -d|-D" options by parsing bitmap in blk-mq layer

Currently, crash doesn't support to display disk I/O statistics for blk-mq devices. For more details, please refer to the following 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(a)redhat.com&gt; --- defs.h | 12 +++ dev.c | 292 ++++++++++++++++++++++++++++++++++++++++++++++-------- symbols.c | 24 +++++ 3 files changed, 289 insertions(+), 39 deletions(-) diff --git a/defs.h b/defs.h index ecbced24d2e3..c1626bc79d59 100644 --- a/defs.h +++ b/defs.h @@ -2170,6 +2170,17 @@ struct offset_table { /* stash of commonly-used offsets */ long sbq_wait_state_wait; long sbitmap_alloc_hint; long sbitmap_round_robin; + long request_q; + long request_cmd_flags; + long request_queue_queue_hw_ctx; + long request_queue_nr_hw_queues; + long blk_mq_hw_ctx_tags; + long blk_mq_hw_ctx_sched_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; + long blk_mq_tags_static_rqs; }; struct size_table { /* stash of commonly-used sizes */ @@ -2339,6 +2350,7 @@ 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..7e0b3d27888d 100644 --- a/dev.c +++ b/dev.c @@ -4238,19 +4238,216 @@ get_one_mctx_diskio(unsigned long mctx, struct diskio *io) io->write = (dispatch[1] - comp[1]); } +typedef uint (busy_tag_iter_fn)(ulong rq, void *data); + +struct bt_iter_data { + ulong q; + struct diskio *dio; +}; + +struct bt_tags_iter_data { + ulong tags; + uint flags; + uint nr_reserved_tags; + busy_tag_iter_fn *fn; + void *data; +}; + +static uint op_is_write(uint op) +{ +#define REQ_OP_BITS 8 +#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1) + + return (op & REQ_OP_MASK) & 1; +} + +static uint calculate_disk_io(ulong rq, void *data) +{ + uint cmd_flags = 0; + ulong addr = 0, queue = 0; + struct bt_iter_data *iter = data; + + if (!IS_KVADDR(rq)) + return 1; + + addr = rq + OFFSET(request_q); + if (!readmem(addr, KVADDR, &queue, sizeof(ulong), "request.q", RETURN_ON_ERROR)) + return 0; + + addr = rq + OFFSET(request_cmd_flags); + if (!readmem(addr, KVADDR, &cmd_flags, sizeof(uint), "request.cmd_flags", RETURN_ON_ERROR)) + return 0; + + if (queue == iter->q) { + if (op_is_write(cmd_flags)) + iter->dio->write++; + else + iter->dio->read++; + } + + return 1; +} + +static bool bt_tags_iter(uint bitnr, void *data) +{ + uint ret = 0; + ulong addr = 0, rqs_addr = 0, rq = 0; + struct bt_tags_iter_data *tag_iter = data; + ulong tag = tag_iter->tags; + + if (!tag_iter->flags) + bitnr += tag_iter->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 ret; + addr = rqs_addr + bitnr * sizeof(ulong); /* rqs[bitnr] */ + if (!readmem(addr, KVADDR, &rq, sizeof(ulong), "blk_mq_tags.rqs[]", RETURN_ON_ERROR)) + return ret; + ret = tag_iter->fn(rq, tag_iter->data); + if (!ret) + return ret; +

+ /* static_rqs */ + ret = 0; + addr = tag + OFFSET(blk_mq_tags_static_rqs); + if (!readmem(addr, KVADDR, &rqs_addr, sizeof(void *), "blk_mq_tags.static_rqs", RETURN_ON_ERROR)) + return ret; + addr = rqs_addr + bitnr * sizeof(ulong); /* static_rqs[bitnr] */ + if (!readmem(addr, KVADDR, &rq, sizeof(ulong), "blk_mq_tags.static_rqs[]", RETURN_ON_ERROR)) + return ret; + ret = tag_iter->fn(rq, tag_iter->data); + + return ret;

+} + +static void bt_tags_for_each(ulong q, ulong tags, ulong sbq, uint flags, uint nr_resvd_tags, struct diskio *dio) +{ + struct sbitmap_context sc = {0}; + struct diskio tmp = {0}; + struct bt_iter_data iter_data = { + .q = q, + .dio = &tmp, + }; + struct bt_tags_iter_data tags_iter_data = { + .tags = tags, + .flags = flags, + .nr_reserved_tags = nr_resvd_tags, + .fn = calculate_disk_io, + .data = &iter_data, + }; + + sbitmap_context_load(sbq + OFFSET(sbitmap_queue_sb), &sc); + sbitmap_for_each_set(&sc, bt_tags_iter, &tags_iter_data); + + dio->read = tmp.read; + dio->write = tmp.write; +} + +static void queue_for_each_hw_ctx(ulong q, ulong *hctx, uint cnt, struct diskio *dio) +{ + uint i; + struct diskio tmp = {0}; + + if (!hctx || !dio) + error(FATAL, "%s: Invalid parameter.\n", __func__); + + for (i = 0; i < cnt; i++) { + ulong addr = 0, tags = 0, sched_tags = 0; + uint nr_reserved_tags = 0; + + if (!IS_KVADDR(hctx[i])) + continue; + + /* 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_tags_for_each(q, tags, addr, 1, nr_reserved_tags, &tmp); + } + addr = tags + OFFSET(blk_mq_tags_bitmap_tags); + bt_tags_for_each(q, tags, addr, 0, nr_reserved_tags, &tmp); +

+ /* Tags owned by I/O scheduler */ + addr = hctx[i] + OFFSET(blk_mq_hw_ctx_sched_tags); + if (!readmem(addr, KVADDR, &sched_tags, sizeof(ulong), + "blk_mq_hw_ctx.sched_tags", RETURN_ON_ERROR)) + break; + + addr = sched_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 = sched_tags + OFFSET(blk_mq_tags_breserved_tags); + bt_tags_for_each(q, sched_tags, addr, 1, nr_reserved_tags, &tmp); + } + addr = sched_tags + OFFSET(blk_mq_tags_bitmap_tags); + bt_tags_for_each(q, sched_tags, addr, 0, nr_reserved_tags, &tmp);

+ } + + dio->read = tmp.read; + dio->write = tmp.write; +} + +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; + struct diskio tmp = {0}; + + 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, &tmp); + dio->read = tmp.read; + dio->write = tmp.write; + + 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 +4676,24 @@ 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)) { @@ -4603,15 +4783,49 @@ void diskio_init(void) MEMBER_OFFSET_INIT(request_queue_rq, "request_queue", "rq"); else MEMBER_OFFSET_INIT(request_queue_rq, "request_queue", "root_rl");

+ if (MEMBER_EXISTS("request", "q")) + MEMBER_OFFSET_INIT(request_q, "request", "q"); + if (MEMBER_EXISTS("request", "cmd_flags")) + MEMBER_OFFSET_INIT(request_cmd_flags, "request", "cmd_flags");

if (MEMBER_EXISTS("request_queue", "mq_ops")) { MEMBER_OFFSET_INIT(request_queue_mq_ops, "request_queue", "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_hw_ctx_sched_tags, "blk_mq_hw_ctx", + "sched_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"); + MEMBER_OFFSET_INIT(blk_mq_tags_static_rqs, "blk_mq_tags", + "static_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_depth, "sbitmap_word", "depth"); + 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 bfe506388fa3..c432469671a4 100644 --- a/symbols.c +++ b/symbols.c @@ -10385,6 +10385,10 @@ dump_offset_table(char *spec, ulong makestruct) OFFSET(kset_list)); fprintf(fp, " request_list_count: %ld\n", OFFSET(request_list_count)); + fprintf(fp, " request_q: %ld\n", + OFFSET(request_q)); + fprintf(fp, " request_cmd_flags: %ld\n", + OFFSET(request_cmd_flags)); fprintf(fp, " request_queue_in_flight: %ld\n", OFFSET(request_queue_in_flight)); fprintf(fp, " request_queue_rq: %ld\n", @@ -10393,10 +10397,29 @@ 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_hw_ctx_sched_tags: %ld\n", + OFFSET(blk_mq_hw_ctx_sched_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, " blk_mq_tags_static_rqs: %ld\n", + OFFSET(blk_mq_tags_static_rqs));

+ fprintf(fp, " subsys_private_klist_devices: %ld\n", OFFSET(subsys_private_klist_devices)); fprintf(fp, " subsystem_kset: %ld\n", @@ -11003,6 +11026,7 @@ 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));