On Thu, 2005-12-15 at 12:18 -0800, Andrew Morton wrote: > Andrew Morton <[email protected]> wrote: > > > > David Howells <[email protected]> wrote: > > > > > > So... Would you then object to an implementation of a mutex appearing in the > > > tree which semaphores that are being used as strict mutexes can be migrated > > > over to as the opportunity arises? > > > > That would be sane. > > > > But not very. > > Look at it from the POV of major architectures: there's no way the new > mutex code will be faster than down() and up(), so we're adding a bunch of > new tricky locking code which bloats the kernel and has to be understood > and debugged for no gain. I see it as a stepping stone for RT ;) > > And I don't buy the debuggability argument really. It'd be pretty simple > to add debug code to the existing semaphore code to trap non-mutex usages. > Then go through the few valid non-mutex users and do: > > #if debug > sem->this_is_not_a_mutex = 1; > #endif That just looks plain ugly. Still, if you want to keep the major archs unchanged (at least until RT is in!) then just add the following: #define mutex_lock(x) down(x) #define mutex_unlock(x) up(x) #define mutex_trylock(x) (!down_trylock(x)) /* see previous email! */ Then you can add your ugly patch ;) where on debug we define those declared with DEFINE_SEM(x) add the this_is_not_a_mutex = 1 -- Steve > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
- References:
- Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation
- From: Andrew Morton <[email protected]>
- Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation
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- Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation
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- Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation
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- [PATCH 1/19] MUTEX: Introduce simple mutex implementation
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