Re: staging: r8188eu: how to handle nested mutex under spinlock

[Pavel Skripkin]

Hi David,

On 4/4/22 11:50, David Laight wrote:
> > > 		while (pwrpriv->bInSuspend &&
> >
> > I've looked into what gcc11 produced from this function and looks like
> > my compiler is smart enough to not cache that value, but I am afraid not
> > all compilers are that smart.
>
> The compiler can't cache the value because of the function call.

Hm, I am a newbie in compilers, so can you, please, explain (or give a 
link to any resource where I can read about it) how function call here 
prevent caching.

IIUC compiler generates code that works well in scope of single-threaded 
application, so why can't compiler cache that value instead of accessing 
memory on each iteration... Isn't register access a way faster than even 
cache hit?


Thanks!

With regards,
Pavel Skripkin

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