diff options
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 45 | ||||
| -rw-r--r-- | init/do_mounts.c | 45 | ||||
| -rw-r--r-- | init/main.c | 2 |
3 files changed, 72 insertions, 20 deletions
diff --git a/init/Kconfig b/init/Kconfig index fed81b5..3ecd8a1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -470,6 +470,7 @@ config TREE_RCU config TREE_PREEMPT_RCU bool "Preemptible tree-based hierarchical RCU" depends on PREEMPT + select IRQ_WORK help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or @@ -527,13 +528,29 @@ config RCU_USER_QS config CONTEXT_TRACKING_FORCE bool "Force context tracking" depends on CONTEXT_TRACKING - default CONTEXT_TRACKING + default y if !NO_HZ_FULL help - Probe on user/kernel boundaries by default in order to - test the features that rely on it such as userspace RCU extended - quiescent states. - This test is there for debugging until we have a real user like the - full dynticks mode. + The major pre-requirement for full dynticks to work is to + support the context tracking subsystem. But there are also + other dependencies to provide in order to make the full + dynticks working. + + This option stands for testing when an arch implements the + context tracking backend but doesn't yet fullfill all the + requirements to make the full dynticks feature working. + Without the full dynticks, there is no way to test the support + for context tracking and the subsystems that rely on it: RCU + userspace extended quiescent state and tickless cputime + accounting. This option copes with the absence of the full + dynticks subsystem by forcing the context tracking on all + CPUs in the system. + + Say Y only if you're working on the developpement of an + architecture backend for the context tracking. + + Say N otherwise, this option brings an overhead that you + don't want in production. + config RCU_FANOUT int "Tree-based hierarchical RCU fanout value" @@ -1106,7 +1123,6 @@ config IPC_NS config USER_NS bool "User namespace" - depends on UIDGID_CONVERTED select UIDGID_STRICT_TYPE_CHECKS default n @@ -1140,20 +1156,8 @@ config NET_NS endif # NAMESPACES -config UIDGID_CONVERTED - # True if all of the selected software conmponents are known - # to have uid_t and gid_t converted to kuid_t and kgid_t - # where appropriate and are otherwise safe to use with - # the user namespace. - bool - default y - - # Filesystems - depends on XFS_FS = n - config UIDGID_STRICT_TYPE_CHECKS bool "Require conversions between uid/gids and their internal representation" - depends on UIDGID_CONVERTED default n help While the nececessary conversions are being added to all subsystems this option allows @@ -1598,7 +1602,7 @@ endchoice config SLUB_CPU_PARTIAL default y - depends on SLUB + depends on SLUB && SMP bool "SLUB per cpu partial cache" help Per cpu partial caches accellerate objects allocation and freeing @@ -1666,6 +1670,7 @@ config BASE_SMALL menuconfig MODULES bool "Enable loadable module support" + option modules help Kernel modules are small pieces of compiled code which can be inserted in the running kernel, rather than being diff --git a/init/do_mounts.c b/init/do_mounts.c index 816014c..a51cddc 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -26,6 +26,8 @@ #include <linux/async.h> #include <linux/fs_struct.h> #include <linux/slab.h> +#include <linux/ramfs.h> +#include <linux/shmem_fs.h> #include <linux/nfs_fs.h> #include <linux/nfs_fs_sb.h> @@ -588,3 +590,46 @@ out: sys_mount(".", "/", NULL, MS_MOVE, NULL); sys_chroot("."); } + +static bool is_tmpfs; +static struct dentry *rootfs_mount(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data) +{ + static unsigned long once; + void *fill = ramfs_fill_super; + + if (test_and_set_bit(0, &once)) + return ERR_PTR(-ENODEV); + + if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs) + fill = shmem_fill_super; + + return mount_nodev(fs_type, flags, data, fill); +} + +static struct file_system_type rootfs_fs_type = { + .name = "rootfs", + .mount = rootfs_mount, + .kill_sb = kill_litter_super, +}; + +int __init init_rootfs(void) +{ + int err = register_filesystem(&rootfs_fs_type); + + if (err) + return err; + + if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] && + (!root_fs_names || strstr(root_fs_names, "tmpfs"))) { + err = shmem_init(); + is_tmpfs = true; + } else { + err = init_ramfs_fs(); + } + + if (err) + unregister_filesystem(&rootfs_fs_type); + + return err; +} diff --git a/init/main.c b/init/main.c index 586cd33..63d3e8f 100644 --- a/init/main.c +++ b/init/main.c @@ -75,6 +75,7 @@ #include <linux/blkdev.h> #include <linux/elevator.h> #include <linux/sched_clock.h> +#include <linux/context_tracking.h> #include <linux/random.h> #include <asm/io.h> @@ -546,6 +547,7 @@ asmlinkage void __init start_kernel(void) idr_init_cache(); rcu_init(); tick_nohz_init(); + context_tracking_init(); radix_tree_init(); /* init some links before init_ISA_irqs() */ early_irq_init(); |