On Wed, 2026-07-01 at 08:57 -0400, Steven Rostedt wrote: > On Wed, 1 Jul 2026 06:11:37 +0000 > Peter Wang (王信友) <[email protected]> wrote: > > > However, I am curious: if the HBA is removed, implying that the > > storage would become unusable, might the system encounter an > > I/O hang or shutdown, potentially preventing its detection? > > Perhaps it's a theoretical issue that would not manifest > > in a real-world situation? > > Note, it doesn't necessarily mean that the device itself was removed. > The > issue is that a pointer to an allocated descriptor is saved in the > ring buffer. > > Maybe once the device is created it will never go way. But what > happens if > for some reason the descriptor is freed and reallocated? Now the old > descriptor pointer is still in the ring buffer. > > What in the logic guarantees that the pointer will never be freed? > > And lets say there is an issue and the hba is freed and you debug > this by > dumping the trace buffer via ftrace_dump_on_oops. Now the dump itself > may > crash and you don't have a way to debug what happened. > > One other point that causes issues here. It makes user space tracing > useless. Try tracing this with "trace-cmd record". These events will > not be > able to be parsed. > > -- Steve >
Hi Steven, Thank you for the detailed explanation. I have no further questions. Thanks Peter
