Re: [Crash-utility] [PATCH] Handle blk_mq_ctx member changes for kernels v5.16-rc1~75^2~44
Hi Lianbo,
-----Original Message-----
Kernel commit <9a14d6ce4135> ("block: remove debugfs
blk_mq_ctx
dispatched/merged/completed attributes") removed the member
rq_dispatched and rq_completed from struct blk_mq_ctx. Without
this patch, crash will fail with the following error:
crash> dev -d
MAJOR GENDISK NAME REQUEST_QUEUE TOTAL ASYNC SYNC
dev: invalid structure member offset: blk_mq_ctx_rq_dispatched
FILE: dev.c LINE: 4229 FUNCTION: get_one_mctx_diskio()
Thank you for working on this.
IIUC, crash will need sbitmap functionality to support this fully.
Meanwhile, I think it's OK to skip the count, but it should say "actually
zero"
or "not supported" so that users can know it, for example:
crash> dev -d
MAJOR GENDISK NAME REQUEST_QUEUE TOTAL ASYNC SYNC
8 ffff92bbd102e400 sdb ffff92bbf04e3678 0 0 0
dev: sdb: Disk I/O statistics is not supported in this kernel
8 ffff92bbd1014400 sdc ffff92bbf04e26e8 0 0 0
dev: sdc: Disk I/O statistics is not supported in this kernel
11 ffff92c347da5e00 sr0 ffff92bbd9c3e528 0 0 0
253 ffff92bbca726e00 dm-0 ffff92bbcad7dd60 0 0 0
What do you think?
Thanks,
Kazu
Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com>
---
dev.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/dev.c b/dev.c
index effe789f38d8..dd21511e5dfc 100644
--- a/dev.c
+++ b/dev.c
@@ -4246,6 +4246,10 @@ get_mq_diskio(unsigned long q, unsigned long *mq_count)
unsigned long mctx_addr;
struct diskio tmp;
+ if (!MEMBER_EXISTS("blk_mq_ctx", "rq_dispatched") &&
+ !MEMBER_EXISTS("blk_mq_ctx", "rq_completed"))
+ return;
+
memset(&tmp, 0x00, sizeof(struct diskio));
readmem(q + OFFSET(request_queue_queue_ctx), KVADDR, &queue_ctx,
--
2.20.1