[dpdk-dev] [PATCH v5] eal: fix allocating all free hugepages

[Sergio Gonzalez Monroy]

On 31/05/2016 04:37, Jianfeng Tan wrote:
> EAL memory init allocates all free hugepages of the whole system,
> which seen from sysfs, even when applications do not ask so many.
> When there is a limitation on how many hugepages an application can
> use (such as cgroup.hugetlb), or hugetlbfs is specified with an
> option of size (exceeding the quota of the fs), it just fails to
> start even there are enough hugepages allocated.
>
> To fix above issue, this patch:
>   - Changes the logic to continue memory init to see if hugetlb
>     requirement of application can be addressed by already allocated
>     hugepages.
>   - To make sure each hugepage is allocated successfully, we add a
>     recover mechanism, which relies on a mem access to fault-in
>     hugepages, and if it fails with SIGBUS, recover to previously
>     saved stack environment with siglongjmp().
>
> For the case of CONFIG_RTE_EAL_SINGLE_FILE_SEGMENTS (enabled by
> default when compiling IVSHMEM target), it's indispensable to
> mapp all free hugepages in the system. Under this case, it fails
> to start when allocating fails.
>
> Test example:
>    a. cgcreate -g hugetlb:/test-subgroup
>    b. cgset -r hugetlb.1GB.limit_in_bytes=2147483648 test-subgroup
>    c. cgexec -g hugetlb:test-subgroup \
>            ./examples/helloworld/build/helloworld -c 0x2 -n 4
>
>         
> Fixes: af75078fece ("first public release")
>
> Signed-off-by: Jianfeng Tan<jianfeng.tan at intel.com>
> Acked-by: Neil Horman<nhorman at tuxdriver.com>
> ---
> v5:
>   - Make this method as default instead of using an option.
>   - When SIGBUS is triggered in the case of RTE_EAL_SINGLE_FILE_SEGMENTS,
>     just return error.
>   - Add prefix "huge_" to newly added function and static variables.
>   - Move the internal_config.memory assignment after the page allocations.
> v4:
>   - Change map_all_hugepages to return unsigned instead of int.
> v3:
>   - Reword commit message to include it fixes the hugetlbfs quota issue.
>   - setjmp -> sigsetjmp.
>   - Fix RTE_LOG complaint from ERR to DEBUG as it does not mean init error
>     so far.
>   - Fix the second map_all_hugepages's return value check.
> v2:
>   - Address the compiling error by move setjmp into a wrap method.
>
>   lib/librte_eal/linuxapp/eal/eal.c        |  20 -----
>   lib/librte_eal/linuxapp/eal/eal_memory.c | 138 ++++++++++++++++++++++++++++---
>   2 files changed, 125 insertions(+), 33 deletions(-)
>

Acked-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy at intel.com>