Messages in this thread | | | Date | Tue, 22 Aug 2000 12:19:39 -0400 | From | "Eric S. Raymond" <> | Subject | Re: [PATCH] Re: Move of input drivers, some word needed from you |
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Linus Torvalds <torvalds@transmeta.com>: > It is NOT true that "shared code means less bugs". People, wake up!
You've ignored what I see as Rogier's main point. It's not "shared code means less bugs" per se, it's "shared code means better test coverage".
Think of each user as testing testing a semi-random sample of the driver's state space for correctness. Then coverage on each line of driver code is proportional to the number of users per driver.
Sharing code is a way to increase the test population for the shared parts, which increases expected test coverage on the shared parts, which is good. It's especially good because the shared parts tend to have subtler bug signatures than the unshared parts (data structure corruption is harder to diagnose than a device lockup), so the better test coverage happens exactly where it's most needed.
Clean APIs also reduce bugs, of course, but that effect is orthogonal to the one Rogier was trying to describe. IMHO, we should strive for both. -- <a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a>
"...quemadmodum gladius neminem occidit, occidentis telum est." [...a sword never kills anybody; it's a tool in the killer's hand.] -- (Lucius Annaeus) Seneca "the Younger" (ca. 4 BC-65 AD), - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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