diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/DMA-attributes.txt | 17 | ||||
-rw-r--r-- | Documentation/RCU/lockdep-splat.txt | 2 | ||||
-rw-r--r-- | Documentation/dev-tools/kmemleak.rst | 9 | ||||
-rw-r--r-- | Documentation/filesystems/autofs4-mount-control.txt | 71 | ||||
-rw-r--r-- | Documentation/filesystems/autofs4.txt | 8 | ||||
-rw-r--r-- | Documentation/kernel-parameters.txt | 50 |
6 files changed, 109 insertions, 48 deletions
diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index 2d455a5..98bf7ac 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -126,3 +126,20 @@ means that we won't try quite as hard to get them. NOTE: At the moment DMA_ATTR_ALLOC_SINGLE_PAGES is only implemented on ARM, though ARM64 patches will likely be posted soon. + +DMA_ATTR_NO_WARN +---------------- + +This tells the DMA-mapping subsystem to suppress allocation failure reports +(similarly to __GFP_NOWARN). + +On some architectures allocation failures are reported with error messages +to the system logs. Although this can help to identify and debug problems, +drivers which handle failures (eg, retry later) have no problems with them, +and can actually flood the system logs with error messages that aren't any +problem at all, depending on the implementation of the retry mechanism. + +So, this provides a way for drivers to avoid those error messages on calls +where allocation failures are not a problem, and shouldn't bother the logs. + +NOTE: At the moment DMA_ATTR_NO_WARN is only implemented on PowerPC. diff --git a/Documentation/RCU/lockdep-splat.txt b/Documentation/RCU/lockdep-splat.txt index bf90611..238e9f6 100644 --- a/Documentation/RCU/lockdep-splat.txt +++ b/Documentation/RCU/lockdep-splat.txt @@ -57,7 +57,7 @@ Call Trace: [<ffffffff817db154>] kernel_thread_helper+0x4/0x10 [<ffffffff81066430>] ? finish_task_switch+0x80/0x110 [<ffffffff817d9c04>] ? retint_restore_args+0xe/0xe - [<ffffffff81097510>] ? __init_kthread_worker+0x70/0x70 + [<ffffffff81097510>] ? __kthread_init_worker+0x70/0x70 [<ffffffff817db150>] ? gs_change+0xb/0xb Line 2776 of block/cfq-iosched.c in v3.0-rc5 is as follows: diff --git a/Documentation/dev-tools/kmemleak.rst b/Documentation/dev-tools/kmemleak.rst index 1788722..b2391b8 100644 --- a/Documentation/dev-tools/kmemleak.rst +++ b/Documentation/dev-tools/kmemleak.rst @@ -162,6 +162,15 @@ See the include/linux/kmemleak.h header for the functions prototype. - ``kmemleak_alloc_recursive`` - as kmemleak_alloc but checks the recursiveness - ``kmemleak_free_recursive`` - as kmemleak_free but checks the recursiveness +The following functions take a physical address as the object pointer +and only perform the corresponding action if the address has a lowmem +mapping: + +- ``kmemleak_alloc_phys`` +- ``kmemleak_free_part_phys`` +- ``kmemleak_not_leak_phys`` +- ``kmemleak_ignore_phys`` + Dealing with false positives/negatives -------------------------------------- diff --git a/Documentation/filesystems/autofs4-mount-control.txt b/Documentation/filesystems/autofs4-mount-control.txt index aff2211..50a3e01 100644 --- a/Documentation/filesystems/autofs4-mount-control.txt +++ b/Documentation/filesystems/autofs4-mount-control.txt @@ -179,8 +179,19 @@ struct autofs_dev_ioctl { * including this struct */ __s32 ioctlfd; /* automount command fd */ - __u32 arg1; /* Command parameters */ - __u32 arg2; + union { + struct args_protover protover; + struct args_protosubver protosubver; + struct args_openmount openmount; + struct args_ready ready; + struct args_fail fail; + struct args_setpipefd setpipefd; + struct args_timeout timeout; + struct args_requester requester; + struct args_expire expire; + struct args_askumount askumount; + struct args_ismountpoint ismountpoint; + }; char path[0]; }; @@ -192,8 +203,8 @@ optionally be used to check a specific mount corresponding to a given mount point file descriptor, and when requesting the uid and gid of the last successful mount on a directory within the autofs file system. -The fields arg1 and arg2 are used to communicate parameters and results of -calls made as described below. +The union is used to communicate parameters and results of calls made +as described below. The path field is used to pass a path where it is needed and the size field is used account for the increased structure length when translating the @@ -245,9 +256,9 @@ AUTOFS_DEV_IOCTL_PROTOVER_CMD and AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD Get the major and minor version of the autofs4 protocol version understood by loaded module. This call requires an initialized struct autofs_dev_ioctl with the ioctlfd field set to a valid autofs mount point descriptor -and sets the requested version number in structure field arg1. These -commands return 0 on success or one of the negative error codes if -validation fails. +and sets the requested version number in version field of struct args_protover +or sub_version field of struct args_protosubver. These commands return +0 on success or one of the negative error codes if validation fails. AUTOFS_DEV_IOCTL_OPENMOUNT and AUTOFS_DEV_IOCTL_CLOSEMOUNT @@ -256,9 +267,9 @@ AUTOFS_DEV_IOCTL_OPENMOUNT and AUTOFS_DEV_IOCTL_CLOSEMOUNT Obtain and release a file descriptor for an autofs managed mount point path. The open call requires an initialized struct autofs_dev_ioctl with the path field set and the size field adjusted appropriately as well -as the arg1 field set to the device number of the autofs mount. The -device number can be obtained from the mount options shown in -/proc/mounts. The close call requires an initialized struct +as the devid field of struct args_openmount set to the device number of +the autofs mount. The device number can be obtained from the mount options +shown in /proc/mounts. The close call requires an initialized struct autofs_dev_ioct with the ioctlfd field set to the descriptor obtained from the open call. The release of the file descriptor can also be done with close(2) so any open descriptors will also be closed at process exit. @@ -272,10 +283,10 @@ AUTOFS_DEV_IOCTL_READY_CMD and AUTOFS_DEV_IOCTL_FAIL_CMD Return mount and expire result status from user space to the kernel. Both of these calls require an initialized struct autofs_dev_ioctl with the ioctlfd field set to the descriptor obtained from the open -call and the arg1 field set to the wait queue token number, received -by user space in the foregoing mount or expire request. The arg2 field -is set to the status to be returned. For the ready call this is always -0 and for the fail call it is set to the errno of the operation. +call and the token field of struct args_ready or struct args_fail set +to the wait queue token number, received by user space in the foregoing +mount or expire request. The status field of struct args_fail is set to +the errno of the operation. It is set to 0 on success. AUTOFS_DEV_IOCTL_SETPIPEFD_CMD @@ -290,9 +301,10 @@ mount be catatonic (see next call). The call requires an initialized struct autofs_dev_ioctl with the ioctlfd field set to the descriptor obtained from the open call and -the arg1 field set to descriptor of the pipe. On success the call -also sets the process group id used to identify the controlling process -(eg. the owning automount(8) daemon) to the process group of the caller. +the pipefd field of struct args_setpipefd set to descriptor of the pipe. +On success the call also sets the process group id used to identify the +controlling process (eg. the owning automount(8) daemon) to the process +group of the caller. AUTOFS_DEV_IOCTL_CATATONIC_CMD @@ -323,9 +335,8 @@ mount on the given path dentry. The call requires an initialized struct autofs_dev_ioctl with the path field set to the mount point in question and the size field adjusted -appropriately as well as the arg1 field set to the device number of the -containing autofs mount. Upon return the struct field arg1 contains the -uid and arg2 the gid. +appropriately. Upon return the uid field of struct args_requester contains +the uid and gid field the gid. When reconstructing an autofs mount tree with active mounts we need to re-connect to mounts that may have used the original process uid and @@ -343,8 +354,9 @@ this ioctl is called until no further expire candidates are found. The call requires an initialized struct autofs_dev_ioctl with the ioctlfd field set to the descriptor obtained from the open call. In addition an immediate expire, independent of the mount timeout, can be -requested by setting the arg1 field to 1. If no expire candidates can -be found the ioctl returns -1 with errno set to EAGAIN. +requested by setting the how field of struct args_expire to 1. If no +expire candidates can be found the ioctl returns -1 with errno set to +EAGAIN. This call causes the kernel module to check the mount corresponding to the given ioctlfd for mounts that can be expired, issues an expire @@ -357,7 +369,8 @@ Checks if an autofs mount point is in use. The call requires an initialized struct autofs_dev_ioctl with the ioctlfd field set to the descriptor obtained from the open call and -it returns the result in the arg1 field, 1 for busy and 0 otherwise. +it returns the result in the may_umount field of struct args_askumount, +1 for busy and 0 otherwise. AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD @@ -369,12 +382,12 @@ The call requires an initialized struct autofs_dev_ioctl. There are two possible variations. Both use the path field set to the path of the mount point to check and the size field adjusted appropriately. One uses the ioctlfd field to identify a specific mount point to check while the other -variation uses the path and optionally arg1 set to an autofs mount type. -The call returns 1 if this is a mount point and sets arg1 to the device -number of the mount and field arg2 to the relevant super block magic -number (described below) or 0 if it isn't a mountpoint. In both cases -the the device number (as returned by new_encode_dev()) is returned -in field arg1. +variation uses the path and optionally in.type field of struct args_ismountpoint +set to an autofs mount type. The call returns 1 if this is a mount point +and sets out.devid field to the device number of the mount and out.magic +field to the relevant super block magic number (described below) or 0 if +it isn't a mountpoint. In both cases the the device number (as returned +by new_encode_dev()) is returned in out.devid field. If supplied with a file descriptor we're looking for a specific mount, not necessarily at the top of the mounted stack. In this case the path diff --git a/Documentation/filesystems/autofs4.txt b/Documentation/filesystems/autofs4.txt index 39d02e1..8fac3fe 100644 --- a/Documentation/filesystems/autofs4.txt +++ b/Documentation/filesystems/autofs4.txt @@ -203,9 +203,9 @@ initiated or is being considered, otherwise it returns 0. Mountpoint expiry ----------------- -The VFS has a mechansim for automatically expiring unused mounts, +The VFS has a mechanism for automatically expiring unused mounts, much as it can expire any unused dentry information from the dcache. -This is guided by the MNT_SHRINKABLE flag. This only applies to +This is guided by the MNT_SHRINKABLE flag. This only applies to mounts that were created by `d_automount()` returning a filesystem to be mounted. As autofs doesn't return such a filesystem but leaves the mounting to the automount daemon, it must involve the automount daemon @@ -298,7 +298,7 @@ remove directories and symlinks using normal filesystem operations. autofs knows whether a process requesting some operation is the daemon or not based on its process-group id number (see getpgid(1)). -When an autofs filesystem it mounted the pgid of the mounting +When an autofs filesystem is mounted the pgid of the mounting processes is recorded unless the "pgrp=" option is given, in which case that number is recorded instead. Any request arriving from a process in that process group is considered to come from the daemon. @@ -450,7 +450,7 @@ Commands are: numbers for existing filesystems can be found in `/proc/self/mountinfo`. - **AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD**: same as `close(ioctlfd)`. -- **AUTOFS_DEV_IOCTL_SETPIPEFD_CMD**: if the filesystem is in +- **AUTOFS_DEV_IOCTL_SETPIPEFD_CMD**: if the filesystem is in catatonic mode, this can provide the write end of a new pipe in `arg1` to re-establish communication with a daemon. The process group of the calling process is used to identify the diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 705fb91..a1489e1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -33,6 +33,37 @@ can also be entered as Double-quotes can be used to protect spaces in values, e.g.: param="spaces in here" +cpu lists: +---------- + +Some kernel parameters take a list of CPUs as a value, e.g. isolcpus, +nohz_full, irqaffinity, rcu_nocbs. The format of this list is: + + <cpu number>,...,<cpu number> + +or + + <cpu number>-<cpu number> + (must be a positive range in ascending order) + +or a mixture + +<cpu number>,...,<cpu number>-<cpu number> + +Note that for the special case of a range one can split the range into equal +sized groups and for each group use some amount from the beginning of that +group: + + <cpu number>-cpu number>:<used size>/<group size> + +For example one can add to the command line following parameter: + + isolcpus=1,2,10-20,100-2000:2/25 + +where the final item represents CPUs 100,101,125,126,150,151,... + + + This document may not be entirely up to date and comprehensive. The command "modinfo -p ${modulename}" shows a current list of all parameters of a loadable module. Loadable modules, after being loaded into the running kernel, also @@ -1789,13 +1820,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See Documentation/filesystems/nfs/nfsroot.txt. irqaffinity= [SMP] Set the default irq affinity mask - Format: - <cpu number>,...,<cpu number> - or - <cpu number>-<cpu number> - (must be a positive range in ascending order) - or a mixture - <cpu number>,...,<cpu number>-<cpu number> + The argument is a cpu list, as described above. irqfixup [HW] When an interrupt is not handled search all handlers @@ -1812,13 +1837,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: <RDP>,<reset>,<pci_scan>,<verbosity> isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. - Format: - <cpu number>,...,<cpu number> - or - <cpu number>-<cpu number> - (must be a positive range in ascending order) - or a mixture - <cpu number>,...,<cpu number>-<cpu number> + The argument is a cpu list, as described above. This option can be used to specify one or more CPUs to isolate from the general SMP balancing and scheduling @@ -2680,6 +2699,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Default: on nohz_full= [KNL,BOOT] + The argument is a cpu list, as described above. In kernels built with CONFIG_NO_HZ_FULL=y, set the specified list of CPUs whose tick will be stopped whenever possible. The boot CPU will be forced outside @@ -3285,6 +3305,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See Documentation/blockdev/ramdisk.txt. rcu_nocbs= [KNL] + The argument is a cpu list, as described above. + In kernels built with CONFIG_RCU_NOCB_CPU=y, set the specified list of CPUs to be no-callback CPUs. Invocation of these CPUs' RCU callbacks will |