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| author | Alistair Popple <alistair@popple.id.au> | 2018-04-17 12:11:29 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-19 14:58:10 +0300 |
| commit | 99c3ce33a00bc40cb218af770ef00c82c8044c36 (patch) | |
| tree | 08501a4dc643b4eae539121bebcefe5e9d1565f9 /arch/powerpc/platforms/powernv/npu-dma.c | |
| parent | d69ccc00c497a4d81fca2dca9bda9f7799971b38 (diff) | |
| download | linux-99c3ce33a00bc40cb218af770ef00c82c8044c36.tar.xz | |
powerpc/powernv/npu: Add a debugfs setting to change ATSD threshold
The threshold at which it becomes more efficient to coalesce a range
of ATSDs into a single per-PID ATSD is currently not well understood
due to a lack of real-world work loads. This patch adds a debugfs
parameter allowing the threshold to be altered at runtime in order to
aid future development and refinement of the value.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/powernv/npu-dma.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/npu-dma.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c index 8cdf91f5d3a4..458315319bd3 100644 --- a/arch/powerpc/platforms/powernv/npu-dma.c +++ b/arch/powerpc/platforms/powernv/npu-dma.c @@ -17,7 +17,9 @@ #include <linux/pci.h> #include <linux/memblock.h> #include <linux/iommu.h> +#include <linux/debugfs.h> +#include <asm/debugfs.h> #include <asm/tlb.h> #include <asm/powernv.h> #include <asm/reg.h> @@ -44,7 +46,8 @@ static DEFINE_SPINLOCK(npu_context_lock); * entire TLB on the GPU for the given PID rather than each specific address in * the range. */ -#define ATSD_THRESHOLD (2*1024*1024) +static uint64_t atsd_threshold = 2 * 1024 * 1024; +static struct dentry *atsd_threshold_dentry; /* * Other types of TCE cache invalidation are not functional in the @@ -683,7 +686,7 @@ static void pnv_npu2_mn_invalidate_range(struct mmu_notifier *mn, struct npu_context *npu_context = mn_to_npu_context(mn); unsigned long address; - if (end - start > ATSD_THRESHOLD) { + if (end - start > atsd_threshold) { /* * Just invalidate the entire PID if the address range is too * large. @@ -958,6 +961,11 @@ int pnv_npu2_init(struct pnv_phb *phb) static int npu_index; uint64_t rc = 0; + if (!atsd_threshold_dentry) { + atsd_threshold_dentry = debugfs_create_x64("atsd_threshold", + 0600, powerpc_debugfs_root, &atsd_threshold); + } + phb->npu.nmmu_flush = of_property_read_bool(phb->hose->dn, "ibm,nmmu-flush"); for_each_child_of_node(phb->hose->dn, dn) { |