Date: Wed, 25 Apr 2007 16:50:13 +0400 From: "Artem Kuchin" <matrix@itlegion.ru> To: "Richard Tector" <richardtector@thekeelecentre.com> Cc: freebsd-stable@freebsd.org Subject: Re: Top not showing 4 cpus on 2 xeons with HT Message-ID: <026301c78738$460bdf50$0c00a8c0@Artem> References: <00e301c7872d$03e1db80$0c00a8c0@Artem> <462F3E60.7010109@thekeelecentre.com>
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Richard Tector wrote: > Artem Kuchin wrote: >> I am just wondering if it is normal. >> I have two xeon processors with HT on each of them. >> When loading kernel says that 4 cpu's are found, >> but when i do top i can see only 0 or 2 in the C >> column. never 1 or 3. Is it normal? >> >> FreeBSD 6.2-STABLE (cvsed 1 day ago) > If I remember correctly, HT is disabled by default for security > reasons but there should be a sysctl to enable it. I believe there is > also a paper by Colin Percival on the issue. ahh, heck, i'll take my chances. I've read the paper and the attack seem to me almost unreal. Also, everybody is in the jail on the server. > Note that in a lot of common loads, the use of HT with the standard > scheduler does not yield any real benefits. Hmm. I just turned it on and already see that hosts are running generally faster (it is a hosting server, 100+ site). No numbers though. It just *SEEMS* faster. Anyway, it cannot make thing slower for sure, or can it? -- Regards, Artem
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