eb0f407a2b
PF_NOFS is a per-process debug flag which is set in current->flags to detect when a process is performing an unsafe allocation. All tasks with PF_NOFS set must strictly use KM_PUSHPAGE for allocations because if they enter direct reclaim and initiate I/O they may deadlock. When debugging is disabled, any incorrect usage will be detected and a call stack with a warning will be printed to the console. The flags will then be automatically corrected to allow for safe execution. If debugging is enabled this will be treated as a fatal condition. To avoid any risk of conflicting with the existing PF_ flags. The PF_NOFS bit shadows the rarely used PF_MUTEX_TESTER bit. Only when CONFIG_RT_MUTEX_TESTER is not set, and we know this bit is unused, will the PF_NOFS bit be valid. Happily, most existing distributions ship a kernel with CONFIG_RT_MUTEX_TESTER disabled. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The Solaris Porting Layer (SPL) is a Linux kernel module which provides many of the Solaris kernel APIs. This shim layer makes it possible to run Solaris kernel code in the Linux kernel with relatively minimal modification. This can be particularly useful when you want to track upstream Solaris development closely and don’t want the overhead of maintaining a large patch which converts Solaris primitives to Linux primitives.
To build packages for your distribution:
$ ./configure
$ make pkg
To copy the kernel code inside your kernel source tree for builtin compilation:
$ ./configure --enable-linux-builtin --with-linux=/usr/src/linux-...
$ ./copy-builtin /usr/src/linux-...
Full documentation for building, configuring, and using the SPL can be found at: http://zfsonlinux.org