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Diffstat (limited to 'Documentation/memory-barriers.txt')
| -rw-r--r-- | Documentation/memory-barriers.txt | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index eaabc3134294..ff07cd3b2f82 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1935,6 +1935,20 @@ There are some more advanced barrier functions: relaxed I/O accessors and the Documentation/DMA-API.txt file for more information on consistent memory. + (*) pmem_wmb(); + + This is for use with persistent memory to ensure that stores for which + modifications are written to persistent storage reached a platform + durability domain. + + For example, after a non-temporal write to pmem region, we use pmem_wmb() + to ensure that stores have reached a platform durability domain. This ensures + that stores have updated persistent storage before any data access or + data transfer caused by subsequent instructions is initiated. This is + in addition to the ordering done by wmb(). + + For load from persistent memory, existing read memory barriers are sufficient + to ensure read ordering. =============================== IMPLICIT KERNEL MEMORY BARRIERS |