diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 3 | ||||
| -rw-r--r-- | Documentation/powerpc/firmware-assisted-dump.txt | 23 | ||||
| -rw-r--r-- | Documentation/vm/transhuge.txt | 10 |
3 files changed, 21 insertions, 15 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 94dd27ef4a76..f42b90687d40 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -694,8 +694,7 @@ struct address_space_operations { write_end: After a successful write_begin, and data copy, write_end must be called. len is the original len passed to write_begin, and copied - is the amount that was able to be copied (copied == len is always true - if write_begin was called with the AOP_FLAG_UNINTERRUPTIBLE flag). + is the amount that was able to be copied. The filesystem must take care of unlocking the page and releasing it refcount, and updating i_size. diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt index 19b1e3d09a19..9cabaf8a207e 100644 --- a/Documentation/powerpc/firmware-assisted-dump.txt +++ b/Documentation/powerpc/firmware-assisted-dump.txt @@ -55,10 +55,14 @@ as follows: booted with restricted memory. By default, the boot memory size will be the larger of 5% of system RAM or 256MB. Alternatively, user can also specify boot memory size - through boot parameter 'fadump_reserve_mem=' which will - override the default calculated size. Use this option - if default boot memory size is not sufficient for second - kernel to boot successfully. + through boot parameter 'crashkernel=' which will override + the default calculated size. Use this option if default + boot memory size is not sufficient for second kernel to + boot successfully. For syntax of crashkernel= parameter, + refer to Documentation/kdump/kdump.txt. If any offset is + provided in crashkernel= parameter, it will be ignored + as fadump reserves memory at end of RAM for boot memory + dump preservation in case of a crash. -- After the low memory (boot memory) area has been saved, the firmware will reset PCI and other hardware state. It will @@ -158,13 +162,16 @@ How to enable firmware-assisted dump (fadump): 1. Set config option CONFIG_FA_DUMP=y and build kernel. 2. Boot into linux kernel with 'fadump=on' kernel cmdline option. -3. Optionally, user can also set 'fadump_reserve_mem=' kernel cmdline +3. Optionally, user can also set 'crashkernel=' kernel cmdline to specify size of the memory to reserve for boot memory dump preservation. -NOTE: If firmware-assisted dump fails to reserve memory then it will - fallback to existing kdump mechanism if 'crashkernel=' option - is set at kernel cmdline. +NOTE: 1. 'fadump_reserve_mem=' parameter has been deprecated. Instead + use 'crashkernel=' to specify size of the memory to reserve + for boot memory dump preservation. + 2. If firmware-assisted dump fails to reserve memory then it + will fallback to existing kdump mechanism if 'crashkernel=' + option is set at kernel cmdline. Sysfs/debugfs files: ------------ diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt index cd28d5ee5273..4dde03b44ad1 100644 --- a/Documentation/vm/transhuge.txt +++ b/Documentation/vm/transhuge.txt @@ -266,7 +266,7 @@ for each mapping. The number of file transparent huge pages mapped to userspace is available by reading ShmemPmdMapped and ShmemHugePages fields in /proc/meminfo. -To identify what applications are mapping file transparent huge pages, it +To identify what applications are mapping file transparent huge pages, it is necessary to read /proc/PID/smaps and count the FileHugeMapped fields for each mapping. @@ -292,7 +292,7 @@ thp_collapse_alloc_failed is incremented if khugepaged found a range the allocation. thp_file_alloc is incremented every time a file huge page is successfully -i allocated. + allocated. thp_file_mapped is incremented every time a file huge page is mapped into user address space. @@ -501,7 +501,7 @@ scanner can get reference to a page is get_page_unless_zero(). All tail pages have zero ->_refcount until atomic_add(). This prevents the scanner from getting a reference to the tail page up to that point. After the -atomic_add() we don't care about the ->_refcount value. We already known how +atomic_add() we don't care about the ->_refcount value. We already known how many references should be uncharged from the head page. For head page get_page_unless_zero() will succeed and we don't mind. It's @@ -519,8 +519,8 @@ comes. Splitting will free up unused subpages. Splitting the page right away is not an option due to locking context in the place where we can detect partial unmap. It's also might be -counterproductive since in many cases partial unmap unmap happens during -exit(2) if an THP crosses VMA boundary. +counterproductive since in many cases partial unmap happens during exit(2) if +a THP crosses a VMA boundary. Function deferred_split_huge_page() is used to queue page for splitting. The splitting itself will happen when we get memory pressure via shrinker |