diff --git a/man2/mmap.2 b/man2/mmap.2 index d9df750c1..d91024ff5 100644 --- a/man2/mmap.2 +++ b/man2/mmap.2 @@ -138,8 +138,8 @@ In contrast when creating mapping of mapping type, the kernel verifies all passed flags are known and fails the mapping with .BR EOPNOTSUPP -otherwise. This mapping type is also required to be able to use some mapping -flags. +otherwise. +This mapping type is also required to be able to use some mapping flags. .TP .B MAP_PRIVATE Create a private copy-on-write mapping. @@ -434,16 +434,20 @@ support can later be transparently implemented for glibc. .BR MAP_SYNC " (since Linux 4.15)" This flags is available only with .B MAP_SHARED_VALIDATE -mapping type. Mappings of +mapping type. +Mappings of .B MAP_SHARED type will silently ignore this flag. -This flag is supported only for files supporting DAX (direct mapping of persistent -memory). For other files, creating mapping with this flag results in +This flag is supported only for files supporting DAX +(direct mapping of persistent memory). +For other files, creating mapping with this flag results in .B EOPNOTSUPP -error. Shared file mappings with this flag provide the guarantee that while -some memory is writeably mapped in the address space of the process, it will -be visible in the same file at the same offset even after the system crashes or -is rebooted. This allows users of such mappings to make data modifications +error. +Shared file mappings with this flag provide the guarantee that while +some memory is writeably mapped in the address space of the process, +it will be visible in the same file at the same offset even after +the system crashes or is rebooted. +This allows users of such mappings to make data modifications persistent in a more efficient way using appropriate CPU instructions. .TP .BR MAP_UNINITIALIZED " (since Linux 2.6.33)"