Re: [PATCH 1/2] block: add blk_default_io_timeout() for avoiding task hung in sync IO

[Ming Lei <ming.lei@redhat.com>]

On Wed, Apr 29, 2020 at 08:08:03PM -0700, Bart Van Assche wrote:
> On 2020-04-28 18:17, Ming Lei wrote:
> > On Tue, Apr 28, 2020 at 07:19:33AM -0700, Bart Van Assche wrote:
> >> On 2020-04-28 00:46, Ming Lei wrote:
> >>> +/*
> >>> + * Used in sync IO for avoiding to triger task hung warning, which may
> >>> + * cause system panic or reboot.
> >>> + */
> >>> +static inline unsigned long blk_default_io_timeout(void)
> >>> +{
> >>> +	return sysctl_hung_task_timeout_secs * (HZ / 2);
> >>> +}
> >>> +
> >>>  #endif
> >>
> >> This function is only used inside the block layer. Has it been
> >> considered to move this function from the public block layer API into a
> >> private header file, e.g. block/blk.h?
> > 
> > Please look at the commit log or the 2nd patch, and the helper will be
> > used in 2nd patch in dio code.
> 
> Has it been considered to use the expression
> "sysctl_hung_task_timeout_secs * (HZ / 2)" directly instead of wrapping
> that expression in a function? I think using the expression directly may
> be more clear. Additionally, it is slightly confusing that the function
> name starts with "blk_" but that nothing in the implementation of that
> function is specific to the block layer.

Fine, will do it in V2.

thanks,
Ming