Messages in this thread | | | Date | Sun, 4 Jan 2004 12:43:56 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: BUG in x86 do_page_fault? [was Re: in_atomic doesn't count local_irq_disable?] |
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On Sun, 4 Jan 2004, Pavel Machek wrote: > > > > Please don't do this, it will result in some _really_ nasty problems with > > X and other programs that potentially disable interrupts in user > > space. > > If user program causes page fault with interrupts disabled, it is > certainly buggy, right?
No.
It may do a best-effort thing. It may also do a best-_performance_ thing, in leaving interrupts disabled over a piece of code that doesn't care, knowing that disabling interrupts is expensive. Or it may just be a simple case of simplicity: disable interrupts over the whole region, knowing that only a part of it matters.
It by no means is automatically a bug. And it unquestionably _does_ happen. We used to warn about it. We stopped.
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