Messages in this thread | | | Date | Tue, 21 Jun 2011 01:01:17 +0800 | From | Cong Wang <> | Subject | Re: [PATCH 1/3] mm: completely disable THP by transparent_hugepage=never |
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于 2011年06月21日 00:50, Andrea Arcangeli 写道: > On Tue, Jun 21, 2011 at 12:34:28AM +0800, Amerigo Wang wrote: >> transparent_hugepage=never should mean to disable THP completely, >> otherwise we don't have a way to disable THP completely. >> The design is broken. > > We want to allow people to boot with transparent_hugepage=never but to > still allow people to enable it later at runtime. Not sure why you > find it broken... Your patch is just crippling down the feature with > no gain. There is absolutely no gain to disallow root to enable THP > later at runtime with sysfs, root can enable it anyway by writing into > /dev/mem.
What can I do if I don't want to see THP at all? I mean the same behavior as when my CPU doesn't have PSE.
With this patch, there is no even /sys/kernel/vm/transparent_hugepage/ exists.
> > Unless you're root and you enable it, it's completely disabled, so I > don't see what you mean it's not completely disabled. Not even > khugepaged is started, try to grep of khugepaged... (that wouldn't be > the same with ksm where ksm daemon runs even when it's off for no > gain, but I explicitly solved the locking so khugepaged will go away > when enabled=never and return when enabled=always).
Without this patch, THP is still initialized (although khugepaged is not started), that is what I don't want to see when I pass "transparent_hugepage=never", because "never" for me means THP is totally unseen, even not initialized.
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