From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- drivers/xen/manage.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/xen/manage.c') diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 5d42d55e299b..2ac4440e7b08 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -3,6 +3,7 @@ */ #include #include +#include #include #include #include -- cgit v1.2.2 From 3fc1f1e27a5b807791d72e5d992aa33b668a6626 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 6 May 2010 18:49:20 +0200 Subject: stop_machine: reimplement using cpu_stop Reimplement stop_machine using cpu_stop. As cpu stoppers are guaranteed to be available for all online cpus, stop_machine_create/destroy() are no longer necessary and removed. With resource management and synchronization handled by cpu_stop, the new implementation is much simpler. Asking the cpu_stop to execute the stop_cpu() state machine on all online cpus with cpu hotplug disabled is enough. stop_machine itself doesn't need to manage any global resources anymore, so all per-instance information is rolled into struct stop_machine_data and the mutex and all static data variables are removed. The previous implementation created and destroyed RT workqueues as necessary which made stop_machine() calls highly expensive on very large machines. According to Dimitri Sivanich, preventing the dynamic creation/destruction makes booting faster more than twice on very large machines. cpu_stop resources are preallocated for all online cpus and should have the same effect. Signed-off-by: Tejun Heo Acked-by: Rusty Russell Acked-by: Peter Zijlstra Cc: Oleg Nesterov Cc: Dimitri Sivanich --- drivers/xen/manage.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) (limited to 'drivers/xen/manage.c') diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 2ac4440e7b08..8943b8ccee1a 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -80,12 +80,6 @@ static void do_suspend(void) shutting_down = SHUTDOWN_SUSPEND; - err = stop_machine_create(); - if (err) { - printk(KERN_ERR "xen suspend: failed to setup stop_machine %d\n", err); - goto out; - } - #ifdef CONFIG_PREEMPT /* If the kernel is preemptible, we need to freeze all the processes to prevent them from being in the middle of a pagetable update @@ -93,7 +87,7 @@ static void do_suspend(void) err = freeze_processes(); if (err) { printk(KERN_ERR "xen suspend: freeze failed %d\n", err); - goto out_destroy_sm; + goto out; } #endif @@ -136,12 +130,8 @@ out_resume: out_thaw: #ifdef CONFIG_PREEMPT thaw_processes(); - -out_destroy_sm: -#endif - stop_machine_destroy(); - out: +#endif shutting_down = SHUTDOWN_INVALID; } #endif /* CONFIG_PM_SLEEP */ -- cgit v1.2.2 From f3bc3189a001ec85c7b1119ad4aa5e39eea0f05e Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 24 May 2010 14:33:41 -0700 Subject: xen: fix build when SYSRQ is disabled Fix build error when CONFIG_MAGIC_SYSRQ is not enabled: drivers/xen/manage.c:223: error: implicit declaration of function 'handle_sysrq' Signed-off-by: Randy Dunlap Acked-by: Jeremy Fitzhardinge Cc: Chris Wright Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/xen/manage.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'drivers/xen/manage.c') diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 8943b8ccee1a..07e857b0de13 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -185,6 +185,7 @@ static void shutdown_handler(struct xenbus_watch *watch, kfree(str); } +#ifdef CONFIG_MAGIC_SYSRQ static void sysrq_handler(struct xenbus_watch *watch, const char **vec, unsigned int len) { @@ -214,15 +215,16 @@ static void sysrq_handler(struct xenbus_watch *watch, const char **vec, handle_sysrq(sysrq_key, NULL); } -static struct xenbus_watch shutdown_watch = { - .node = "control/shutdown", - .callback = shutdown_handler -}; - static struct xenbus_watch sysrq_watch = { .node = "control/sysrq", .callback = sysrq_handler }; +#endif + +static struct xenbus_watch shutdown_watch = { + .node = "control/shutdown", + .callback = shutdown_handler +}; static int setup_shutdown_watcher(void) { @@ -234,11 +236,13 @@ static int setup_shutdown_watcher(void) return err; } +#ifdef CONFIG_MAGIC_SYSRQ err = register_xenbus_watch(&sysrq_watch); if (err) { printk(KERN_ERR "Failed to set sysrq watcher\n"); return err; } +#endif return 0; } -- cgit v1.2.2