diff options
| author | Baolin Wang <baolin.wang@linux.alibaba.com> | 2021-11-05 13:41:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 13:30:39 -0700 |
| commit | 38e719ab26735aa2c5d9d422fc4b741cbd36e700 (patch) | |
| tree | 0259e625d5c1c364b3f42a4936ee8f94b9fd1506 /Documentation | |
| parent | 12b613206474cea36671d6e3a7be7d1db7eb8741 (diff) | |
hugetlb: support node specified when using cma for gigantic hugepages
Now the size of CMA area for gigantic hugepages runtime allocation is
balanced for all online nodes, but we also want to specify the size of
CMA per-node, or only one node in some cases, which are similar with
patch [1].
For example, on some multi-nodes systems, each node's memory can be
different, allocating the same size of CMA for each node is not suitable
for the low-memory nodes. Meanwhile some workloads like DPDK mentioned
by Zhenguo in patch [1] only need hugepages in one node.
On the other hand, we have some machines with multiple types of memory,
like DRAM and PMEM (persistent memory). On this system, we may want to
specify all the hugepages only on DRAM node, or specify the proportion
of DRAM node and PMEM node, to tuning the performance of the workloads.
Thus this patch adds node format for 'hugetlb_cma' parameter to support
specifying the size of CMA per-node. An example is as follows:
hugetlb_cma=0:5G,2:5G
which means allocating 5G size of CMA area on node 0 and node 2
respectively. And the users should use the node specific sysfs file to
allocate the gigantic hugepages if specified the CMA size on that node.
Link: https://lkml.kernel.org/r/20211005054729.86457-1-yaozhenguo1@gmail.com [1]
Link: https://lkml.kernel.org/r/bb790775ca60bb8f4b26956bb3f6988f74e075c7.1634261144.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 43dc35fe5bc0..e7f7904edf20 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1587,8 +1587,10 @@ registers. Default set by CONFIG_HPET_MMAP_DEFAULT. hugetlb_cma= [HW,CMA] The size of a CMA area used for allocation - of gigantic hugepages. - Format: nn[KMGTPE] + of gigantic hugepages. Or using node format, the size + of a CMA area per node can be specified. + Format: nn[KMGTPE] or (node format) + <node>:nn[KMGTPE][,<node>:nn[KMGTPE]] Reserve a CMA area of given size and allocate gigantic hugepages using the CMA allocator. If enabled, the |