diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/block/bfq-iosched.txt | 43 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/thermal/brcm,avs-tmon.txt | 20 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/thermal/imx-thermal.txt | 7 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/thermal/rockchip-thermal.txt | 1 | ||||
| -rw-r--r-- | Documentation/filesystems/cramfs.txt | 42 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 4 | ||||
| -rw-r--r-- | Documentation/gpu/todo.rst | 10 | ||||
| -rw-r--r-- | Documentation/power/runtime_pm.txt | 3 |
8 files changed, 118 insertions, 12 deletions
diff --git a/Documentation/block/bfq-iosched.txt b/Documentation/block/bfq-iosched.txt index 3d6951d63489..8d8d8f06cab2 100644 --- a/Documentation/block/bfq-iosched.txt +++ b/Documentation/block/bfq-iosched.txt @@ -20,12 +20,27 @@ for that device, by setting low_latency to 0. See Section 3 for details on how to configure BFQ for the desired tradeoff between latency and throughput, or on how to maximize throughput. -On average CPUs, the current version of BFQ can handle devices -performing at most ~30K IOPS; at most ~50 KIOPS on faster CPUs. As a -reference, 30-50 KIOPS correspond to very high bandwidths with -sequential I/O (e.g., 8-12 GB/s if I/O requests are 256 KB large), and -to 120-200 MB/s with 4KB random I/O. BFQ is currently being tested on -multi-queue devices too. +BFQ has a non-null overhead, which limits the maximum IOPS that a CPU +can process for a device scheduled with BFQ. To give an idea of the +limits on slow or average CPUs, here are, first, the limits of BFQ for +three different CPUs, on, respectively, an average laptop, an old +desktop, and a cheap embedded system, in case full hierarchical +support is enabled (i.e., CONFIG_BFQ_GROUP_IOSCHED is set), but +CONFIG_DEBUG_BLK_CGROUP is not set (Section 4-2): +- Intel i7-4850HQ: 400 KIOPS +- AMD A8-3850: 250 KIOPS +- ARM CortexTM-A53 Octa-core: 80 KIOPS + +If CONFIG_DEBUG_BLK_CGROUP is set (and of course full hierarchical +support is enabled), then the sustainable throughput with BFQ +decreases, because all blkio.bfq* statistics are created and updated +(Section 4-2). For BFQ, this leads to the following maximum +sustainable throughputs, on the same systems as above: +- Intel i7-4850HQ: 310 KIOPS +- AMD A8-3850: 200 KIOPS +- ARM CortexTM-A53 Octa-core: 56 KIOPS + +BFQ works for multi-queue devices too. The table of contents follow. Impatients can just jump to Section 3. @@ -500,6 +515,22 @@ BFQ-specific files is "blkio.bfq." or "io.bfq." For example, the group parameter to set the weight of a group with BFQ is blkio.bfq.weight or io.bfq.weight. +As for cgroups-v1 (blkio controller), the exact set of stat files +created, and kept up-to-date by bfq, depends on whether +CONFIG_DEBUG_BLK_CGROUP is set. If it is set, then bfq creates all +the stat files documented in +Documentation/cgroup-v1/blkio-controller.txt. If, instead, +CONFIG_DEBUG_BLK_CGROUP is not set, then bfq creates only the files +blkio.bfq.io_service_bytes +blkio.bfq.io_service_bytes_recursive +blkio.bfq.io_serviced +blkio.bfq.io_serviced_recursive + +The value of CONFIG_DEBUG_BLK_CGROUP greatly influences the maximum +throughput sustainable with bfq, because updating the blkio.bfq.* +stats is rather costly, especially for some of the stats enabled by +CONFIG_DEBUG_BLK_CGROUP. + Parameters to set ----------------- diff --git a/Documentation/devicetree/bindings/thermal/brcm,avs-tmon.txt b/Documentation/devicetree/bindings/thermal/brcm,avs-tmon.txt new file mode 100644 index 000000000000..9d43553a8d39 --- /dev/null +++ b/Documentation/devicetree/bindings/thermal/brcm,avs-tmon.txt @@ -0,0 +1,20 @@ +* Broadcom STB thermal management + +Thermal management core, provided by the AVS TMON hardware block. + +Required properties: +- compatible: must be "brcm,avs-tmon" and/or "brcm,avs-tmon-bcm7445" +- reg: address range for the AVS TMON registers +- interrupts: temperature monitor interrupt, for high/low threshold triggers +- interrupt-names: should be "tmon" +- interrupt-parent: the parent interrupt controller + +Example: + + thermal@f04d1500 { + compatible = "brcm,avs-tmon-bcm7445", "brcm,avs-tmon"; + reg = <0xf04d1500 0x28>; + interrupts = <0x6>; + interrupt-names = "tmon"; + interrupt-parent = <&avs_host_l2_intc>; + }; diff --git a/Documentation/devicetree/bindings/thermal/imx-thermal.txt b/Documentation/devicetree/bindings/thermal/imx-thermal.txt index 3c67bd50aa10..28be51afdb6a 100644 --- a/Documentation/devicetree/bindings/thermal/imx-thermal.txt +++ b/Documentation/devicetree/bindings/thermal/imx-thermal.txt @@ -7,10 +7,17 @@ Required properties: is higher than panic threshold, system will auto reboot by SRC module. - fsl,tempmon : phandle pointer to system controller that contains TEMPMON control registers, e.g. ANATOP on imx6q. +- nvmem-cells: A phandle to the calibration cells provided by ocotp. +- nvmem-cell-names: Should be "calib", "temp_grade". + +Deprecated properties: - fsl,tempmon-data : phandle pointer to fuse controller that contains TEMPMON calibration data, e.g. OCOTP on imx6q. The details about calibration data can be found in SoC Reference Manual. +Direct access to OCOTP via fsl,tempmon-data is incorrect on some newer chips +because it does not handle OCOTP clock requirements. + Optional properties: - clocks : thermal sensor's clock source. diff --git a/Documentation/devicetree/bindings/thermal/rockchip-thermal.txt b/Documentation/devicetree/bindings/thermal/rockchip-thermal.txt index e3a6234fb1ac..43d744e5305e 100644 --- a/Documentation/devicetree/bindings/thermal/rockchip-thermal.txt +++ b/Documentation/devicetree/bindings/thermal/rockchip-thermal.txt @@ -2,6 +2,7 @@ Required properties: - compatible : should be "rockchip,<name>-tsadc" + "rockchip,rv1108-tsadc": found on RV1108 SoCs "rockchip,rk3228-tsadc": found on RK3228 SoCs "rockchip,rk3288-tsadc": found on RK3288 SoCs "rockchip,rk3328-tsadc": found on RK3328 SoCs diff --git a/Documentation/filesystems/cramfs.txt b/Documentation/filesystems/cramfs.txt index 4006298f6707..8e19a53d648b 100644 --- a/Documentation/filesystems/cramfs.txt +++ b/Documentation/filesystems/cramfs.txt @@ -45,6 +45,48 @@ you can just change the #define in mkcramfs.c, so long as you don't mind the filesystem becoming unreadable to future kernels. +Memory Mapped cramfs image +-------------------------- + +The CRAMFS_MTD Kconfig option adds support for loading data directly from +a physical linear memory range (usually non volatile memory like Flash) +instead of going through the block device layer. This saves some memory +since no intermediate buffering is necessary to hold the data before +decompressing. + +And when data blocks are kept uncompressed and properly aligned, they will +automatically be mapped directly into user space whenever possible providing +eXecute-In-Place (XIP) from ROM of read-only segments. Data segments mapped +read-write (hence they have to be copied to RAM) may still be compressed in +the cramfs image in the same file along with non compressed read-only +segments. Both MMU and no-MMU systems are supported. This is particularly +handy for tiny embedded systems with very tight memory constraints. + +The location of the cramfs image in memory is system dependent. You must +know the proper physical address where the cramfs image is located and +configure an MTD device for it. Also, that MTD device must be supported +by a map driver that implements the "point" method. Examples of such +MTD drivers are cfi_cmdset_0001 (Intel/Sharp CFI flash) or physmap +(Flash device in physical memory map). MTD partitions based on such devices +are fine too. Then that device should be specified with the "mtd:" prefix +as the mount device argument. For example, to mount the MTD device named +"fs_partition" on the /mnt directory: + +$ mount -t cramfs mtd:fs_partition /mnt + +To boot a kernel with this as root filesystem, suffice to specify +something like "root=mtd:fs_partition" on the kernel command line. + + +Tools +----- + +A version of mkcramfs that can take advantage of the latest capabilities +described above can be found here: + +https://github.com/npitre/cramfs-tools + + For /usr/share/magic -------------------- diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 93e0a2404532..17bb4dc28fae 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -502,10 +502,6 @@ in your dentry operations instead. store it as cookie. -- [mandatory] - __fd_install() & fd_install() can now sleep. Callers should not - hold a spinlock or other resources that do not allow a schedule. --- -[mandatory] any symlink that might use page_follow_link_light/page_put_link() must have inode_nohighmem(inode) called before anything might start playing with its pagecache. No highmem pages should end up in the pagecache of such diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 96f8ec7dbe4e..36625aa66c27 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -409,5 +409,15 @@ those drivers as simple as possible, so lots of room for refactoring: Contact: Noralf Trønnes, Daniel Vetter +AMD DC Display Driver +--------------------- + +AMD DC is the display driver for AMD devices starting with Vega. There has been +a bunch of progress cleaning it up but there's still plenty of work to be done. + +See drivers/gpu/drm/amd/display/TODO for tasks. + +Contact: Harry Wentland, Alex Deucher + Outside DRM =========== diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 57af2f7963ee..937e33c46211 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -435,8 +435,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: PM status to 'suspended' and update its parent's counter of 'active' children as appropriate (it is only valid to use this function if 'power.runtime_error' is set or 'power.disable_depth' is greater than - zero); it will fail and return an error code if the device has a child - which is active and the 'power.ignore_children' flag is unset + zero) bool pm_runtime_active(struct device *dev); - return true if the device's runtime PM status is 'active' or its |