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path: root/include/linux/cpu.h
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2005-11-28[PATCH] clean up lock_cpu_hotplug() in cpufreqAshok Raj
There are some callers in cpufreq hotplug notify path that the lowest function calls lock_cpu_hotplug(). The lock is already held during cpu_up() and cpu_down() calls when the notify calls are broadcast to registered clients. Ideally if possible, we could disable_preempt() at the highest caller and make sure we dont sleep in the path down in cpufreq->driver_target() calls but the calls are so intertwined and cumbersome to cleanup. Hence we consistently use lock_cpu_hotplug() and unlock_cpu_hotplug() in all places. - Removed export of cpucontrol semaphore and made it static. - removed explicit uses of up/down with lock_cpu_hotplug() so we can keep track of the the callers in same thread context and just keep refcounts without calling a down() that causes a deadlock. - Removed current_in_hotplug() uses - Removed PF_HOTPLUG_CPU in sched.h introduced for the current_in_hotplug() temporary workaround. Tested with insmod of cpufreq_stat.ko, and logical online/offline to make sure we dont have any hang situations. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Cc: Zwane Mwaikambo <zwane@linuxpower.ca> Cc: Shaohua Li <shaohua.li@intel.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09[PATCH] cpu hotplug: fix locking in cpufreq driversAshok Raj
When calling target drivers to set frequency, we take cpucontrol lock. When we modified the code to accomodate CPU hotplug, there was an attempt to take a double lock of cpucontrol leading to a deadlock. Since the current thread context is already holding the cpucontrol lock, we dont need to make another attempt to acquire it. Now we leave a trace in current->flags indicating current thread already is under cpucontrol lock held, so we dont attempt to do this another time. Thanks to Andrew Morton for the beating:-) From: Brice Goglin <Brice.Goglin@ens-lyon.org> Build fix (akpm: this patch is still unpleasant. Ashok continues to look for a cleaner solution, doesn't he? ;)) Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] introduce get_cpu_sysdev() to retrieve a sysfs entry for a cpu.Ashok Raj
Some modules creating sysfs entries under /sys/devices/system/cpu/cpuX/ need to know the parent sysfs entry to make devices under them. This will just return the sysfs entry for a given cpu. sysfs entries showing under each cpu sysfs can be easily created if such entries can be created by registering a sysfs driver for cpuclass. The issue is when the entry is created the CPU may not be online, hence we would need to defer the creation until the online notification comes. Current users: cache entries for Intel CPU's and cpufreq subsystem. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Zwane Mwaikambo <zwane@holomorphy.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-02[PATCH] remove driverfs references from include/linux/cpu.h and ↵Rolf Eike Beer
net/sunrpc/rpc_pipe.c This patch is against 2.6.10, but still applies cleanly. It's just s/driverfs/sysfs/ in these two files. Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] make smp_prepare_cpu to a weak functionAshok Raj
I really wish smp_prepare_cpu() would disappear eventually. In the interim this is ideally a weak function, so we dont end up changing several places to define this dummy in headers. Today since the dummy declaration is done only in drivers/base/cpu.c but the function is called in kernel/power/smp.c i get undefined reference in my cpu hotplug code for x86_64 under development. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!