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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2017-08-07 15:16:15 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-08-09 15:09:35 +0200 |
| commit | 3f4298427ad521fdc74fb991b17d84959513218a (patch) | |
| tree | c4a9cff2e5ac1261c745b74dc3a70a644fd448bd /arch/s390 | |
| parent | s390/cpcmd,vmcp: avoid GFP_DMA allocations (diff) | |
| download | linux-3f4298427ad521fdc74fb991b17d84959513218a.tar.xz linux-3f4298427ad521fdc74fb991b17d84959513218a.zip | |
s390/vmcp: make use of contiguous memory allocator
If memory is fragmented it is unlikely that large order memory
allocations succeed. This has been an issue with the vmcp device
driver since a long time, since it requires large physical contiguous
memory ares for large responses.
To hopefully resolve this issue make use of the contiguous memory
allocator (cma). This patch adds a vmcp specific vmcp cma area with a
default size of 4MB. The size can be changed either via the
VMCP_CMA_SIZE config option at compile time or with the "vmcp_cma"
kernel parameter (e.g. "vmcp_cma=16m").
For any vmcp response buffers larger than 16k memory from the cma area
will be allocated. If such an allocation fails, there is a fallback to
the buddy allocator.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/setup.h | 6 | ||||
| -rw-r--r-- | arch/s390/kernel/setup.c | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h index 61da4bd6edad..490e035b3716 100644 --- a/arch/s390/include/asm/setup.h +++ b/arch/s390/include/asm/setup.h @@ -108,6 +108,12 @@ extern void pfault_fini(void); #define pfault_fini() do { } while (0) #endif /* CONFIG_PFAULT */ +#ifdef CONFIG_VMCP +void vmcp_cma_reserve(void); +#else +static inline void vmcp_cma_reserve(void) { } +#endif + void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault); void cmma_init(void); diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index a50238e17867..164a1e16b53e 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -925,6 +925,7 @@ void __init setup_arch(char **cmdline_p) setup_memory_end(); setup_memory(); dma_contiguous_reserve(memory_end); + vmcp_cma_reserve(); check_initrd(); reserve_crashkernel(); |