diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2023-01-25 12:23:46 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-01-28 15:32:36 -0800 |
| commit | c91d713630848460de8669e6570307b7e559863b (patch) | |
| tree | feeb34b196684b0b3f1ba09cacadc03ed93a920d /drivers/nvdimm/nd.h | |
| parent | fb6df4366f86dd252bfa3049edffa52d17e7b895 (diff) | |
nvdimm: Support sizeof(struct page) > MAX_STRUCT_PAGE_SIZE
Commit 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE")
...updated MAX_STRUCT_PAGE_SIZE to account for sizeof(struct page)
potentially doubling in the case of CONFIG_KMSAN=y. Unfortunately this
doubles the amount of capacity stolen from user addressable capacity for
everyone, regardless of whether they are using the debug option. Revert
that change, mandate that MAX_STRUCT_PAGE_SIZE never exceed 64, but
allow for debug scenarios to proceed with creating debug sized page maps
with a compile option to support debug scenarios.
Note that this only applies to cases where the page map is permanent,
i.e. stored in a reservation of the pmem itself ("--map=dev" in "ndctl
create-namespace" terms). For the "--map=mem" case, since the allocation
is ephemeral for the lifespan of the namespace, there are no explicit
restriction. However, the implicit restriction, of having enough
available "System RAM" to store the page map for the typically large
pmem, still applies.
Fixes: 6e9f05dc66f9 ("libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE")
Cc: <stable@vger.kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Link: https://lore.kernel.org/r/167467815773.463042.7022545814443036382.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/nd.h')
| -rw-r--r-- | drivers/nvdimm/nd.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index 85ca5b4da3cf..ec5219680092 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -652,7 +652,7 @@ void devm_namespace_disable(struct device *dev, struct nd_namespace_common *ndns); #if IS_ENABLED(CONFIG_ND_CLAIM) /* max struct page size independent of kernel config */ -#define MAX_STRUCT_PAGE_SIZE 128 +#define MAX_STRUCT_PAGE_SIZE 64 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap); #else static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, |