forked from Minki/linux
mainlining shenanigans
1383cb8103
When a system is under memory presure (high usage with fragments), the original 256KB ICM chunk allocations will likely trigger kernel memory management to enter slow path doing memory compact/migration ops in order to complete high order memory allocations. When that happens, user processes calling uverb APIs may get stuck for more than 120s easily even though there are a lot of free pages in smaller chunks available in the system. Syslog: ... Dec 10 09:04:51 slcc03db02 kernel: [397078.572732] INFO: task oracle_205573_e:205573 blocked for more than 120 seconds. ... With 4KB ICM chunk size on x86_64 arch, the above issue is fixed. However in order to support smaller ICM chunk size, we need to fix another issue in large size kcalloc allocations. E.g. Setting log_num_mtt=30 requires 1G mtt entries. With the 4KB ICM chunk size, each ICM chunk can only hold 512 mtt entries (8 bytes for each mtt entry). So we need a 16MB allocation for a table->icm pointer array to hold 2M pointers which can easily cause kcalloc to fail. The solution is to use kvzalloc to replace kcalloc which will fall back to vmalloc automatically if kmalloc fails. Signed-off-by: Qing Huang <qing.huang@oracle.com> Acked-by: Daniel Jurgens <danielj@mellanox.com> Reviewed-by: Zhu Yanjun <yanjun.zhu@oracle.com> Reviewed-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| certs | ||
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| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.