Messages in this thread | | | Subject | Re: [PATCH] mm/hugetlb: suppress wrong warning info when alloc gigantic page | From | David Hildenbrand <> | Date | Thu, 4 Mar 2021 18:21:54 +0100 |
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On 04.03.21 18:20, Mike Kravetz wrote: > On 3/4/21 1:35 AM, David Hildenbrand wrote: >> On 19.02.21 20:14, Mike Kravetz wrote: >>> On 2/19/21 4:39 AM, Chen Wandun wrote: >>>> If hugetlb_cma is enabled, it will skip boot time allocation >>>> when allocating gigantic page, that doesn't means allocation >>>> failure, so suppress this warning info. >>>> >>> >>> Normally the addition of warning messages is discouraged. However, in >>> this case the additional message provides value. Why? >>> >>> Prior to the commit cf11e85fc08c, one could have a kernel command line >>> that contains: >>> >>> hugepagesz=1G hugepages=16 >>> >>> This would allocate 16 1G pages at boot time. >>> >>> After the commit, someone could specify a command line containing: >>> >>> hugepagesz=1G hugepages=16 hugetlb_cma=16G >>> >>> In this case, 16G of CMA will be reserved for 1G huge page allocations >>> after boot time. The parameter 'hugepages=16' is ignored, and the warning >>> message is logged. The warning message should only be logged when the >>> kernel parameter 'hugepages=' is ignored. >>> >>> IMO, it make sense to log a warning if ignoring a user specified parameter. >>> The user should not be attempting boot time allocation and CMA reservation >>> for 1G pages. >>> >>> I do not think we should drop the warning as the it tells the user thay >>> have specified two incompatible allocation options. >>> >> >> I agree. It has value. >> > > Hi David, > > Sorry my above reply was too quick as I did not take a close look at > the code/patch. See, > > https://lore.kernel.org/mm-commits/YDAbeDsG7GhV6s6B@carbon.dhcp.thefacebook.com/ > > This patch is actually in Andrew's tree. >
Oh, I missed that discussion - thanks for the pointer!
-- Thanks,
David / dhildenb
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