我已经配置了用于
Java的巨大页面,虽然我对/ proc / meminfo中的会计有疑问,但它似乎运行良好.为了显示
# grep HugePages /proc/meminfo AnonHugePages: 274432 kB HugePages_Total: 1008 HugePages_Free: 596 HugePages_Rsvd: 594 HugePages_Surp: 0
我的问题涉及“免费”和“Rsvd”号码 – 为什么它们不加起来总计1008？他们实际上加起来是1190.我在这里不理解什么？
解决方法
这是因为HugePages_rsvd基本上是从HugePages_Free中读取的.意思是,在596个免费的大页面中,有594个已被某些应用程序保留使用.那就是内核承诺这些594个大页面可用于该应用程序.
如果现在有3个大页面的请求,那么它将失败,因为只有2个可用于保留.将其视为malloc()调用,当您保留内存虚拟页面以考虑进程的VSZ时,但当进程实际使用它们时,它将成为进程的RSZ(运行集).
由于大页面总是驻留在主内存上,当应用程序请求它们时,内核会从空闲池中减少它并增加Rsvd计数器.
这是来自内核源代码. https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt
where:
HugePages_Total is the size of the pool of huge pages.
HugePages_Free is the number of huge pages in the pool that are not yet
allocated.
HugePages_Rsvd is short for "reserved," and is the number of huge pages for
which a commitment to allocate from the pool has been made,but no allocation has yet been made. Reserved huge pages
guarantee that an application will be able to allocate a
huge page from the pool of huge pages at fault time.
HugePages_Surp is short for "surplus," and is the number of huge pages in
the pool above the value in /proc/sys/vm/nr_hugepages. The
maximum number of surplus huge pages is controlled by
/proc/sys/vm/nr_overcommit_hugepages.
