Messages in this thread | | | Subject | Re: [PATCH] proc/meminfo: add MemKernel counter | From | Konstantin Khlebnikov <> | Date | Wed, 22 May 2019 19:09:22 +0300 |
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On 22.05.2019 18:52, Michal Hocko wrote: > On Wed 22-05-19 17:40:09, Konstantin Khlebnikov wrote: >> Some kinds of kernel allocations are not accounted or not show in meminfo. >> For example vmalloc allocations are tracked but overall size is not shown >> for performance reasons. There is no information about network buffers. >> >> In most cases detailed statistics is not required. At first place we need >> information about overall kernel memory usage regardless of its structure. >> >> This patch estimates kernel memory usage by subtracting known sizes of >> free, anonymous, hugetlb and caches from total memory size: MemKernel = >> MemTotal - MemFree - Buffers - Cached - SwapCached - AnonPages - Hugetlb. > > Why do we need to export something that can be calculated in the > userspace trivially? Also is this really something the number really > meaningful? Say you have a driver that exports memory to the userspace > via mmap but that memory is not accounted. Is this really a kernel > memory? >
It may be trivial right now but not fixed. Adding new kinds of memory may change this definition. For example hypothetical 'GPU buffers' may be handled as 'userspace' memory.
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