Date: Tue, 12 May 1998 18:21:30 +1000 From: Bruce Evans <bde@zeta.org.au> To: freebsd-bugs@FreeBSD.ORG, Tor.Egge@idi.ntnu.no Subject: Re: kern/6587: SMP idle cpl breaks signal forwarding Message-ID: <199805120821.SAA27380@godzilla.zeta.org.au>
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> Having a shared AST flag in an SMP configuration is wrong. > This is one of the bad side effects. I think never setting it in cpl might be best. The swi_ast_phantom code should handle unexpected swi_ast's. This is probably an optimization, even in the UP case - swi_ast's are relatively rare, and phantom ones would still be relatively rarer (new ones would only occur when there is certain interrupt handling between the setting of SWI_AST in ipending and return to user mode), so testing the RPL bits in the trap frame should be cheaper than toggling SWI_AST in cpl for every syscall. The shared AST flag in ipending may be correct even for SMP. It gets multiplexed by trap(). Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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