Messages in this thread | | | Date | Fri, 20 Sep 2002 15:43:47 +0400 | From | Oleg Drokin <> | Subject | Re: [patch] generic-pidhash-2.5.36-D4, BK-curr |
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Hello!
On Fri, Sep 20, 2002 at 11:40:16AM +0200, Ingo Molnar wrote: > > > + if (cmpxchg(&map->page, NULL, page)) > > > + free_page(page); > > Note that this piece breaks compilation for every arch that does not > > have cmpxchg implementation. > > This is the case with x86 (with CONFIG_X86_CMPXCHG undefined, e.g. i386), > > ARM, CRIS, m68k, MIPS, MIPS64, PARISC, s390, SH, sparc32, UML (for x86). > we need a cmpxchg() function in the generic library, using a spinlock.
But this is not safe for arches that provides SMP but does not provide cmpxchg in hadware, right? I mean it is only safe to use such spinlock-based function if all other places read and write this value via special functions that are also taking this spinlock. Do you think we can count on this?
Bye, Oleg - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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