Searched hist:"3 e401f7a2e5199151f735aee6a5c6b4776e6a35e" (Results 1 – 3 of 3) sorted by relevance
/openbmc/linux/arch/powerpc/kernel/ |
H A D | rtasd.c | diff 3e401f7a2e5199151f735aee6a5c6b4776e6a35e Tue Jun 20 17:08:30 CDT 2017 Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> powerpc: Only obtain cpu_hotplug_lock if called by rtasd
Calling arch_update_cpu_topology from a CPU hotplug state machine callback hits a deadlock because the function tries to get a read lock on cpu_hotplug_lock while the state machine still holds a write lock on it.
Since all callers of arch_update_cpu_topology except rtasd already hold cpu_hotplug_lock, this patch changes the function to use stop_machine_cpuslocked and creates a separate function for rtasd which still tries to obtain the lock.
Michael Bringmann investigated the bug and provided a detailed analysis of the deadlock on this previous RFC for an alternate solution:
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michael Bringmann <mwb@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1497996510-4032-1-git-send-email-bauerman@linux.vnet.ibm.com Link: https://patchwork.ozlabs.org/patch/771293/
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/openbmc/linux/arch/powerpc/include/asm/ |
H A D | topology.h | diff 3e401f7a2e5199151f735aee6a5c6b4776e6a35e Tue Jun 20 17:08:30 CDT 2017 Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> powerpc: Only obtain cpu_hotplug_lock if called by rtasd
Calling arch_update_cpu_topology from a CPU hotplug state machine callback hits a deadlock because the function tries to get a read lock on cpu_hotplug_lock while the state machine still holds a write lock on it.
Since all callers of arch_update_cpu_topology except rtasd already hold cpu_hotplug_lock, this patch changes the function to use stop_machine_cpuslocked and creates a separate function for rtasd which still tries to obtain the lock.
Michael Bringmann investigated the bug and provided a detailed analysis of the deadlock on this previous RFC for an alternate solution:
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michael Bringmann <mwb@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1497996510-4032-1-git-send-email-bauerman@linux.vnet.ibm.com Link: https://patchwork.ozlabs.org/patch/771293/
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/openbmc/linux/arch/powerpc/mm/ |
H A D | numa.c | diff 3e401f7a2e5199151f735aee6a5c6b4776e6a35e Tue Jun 20 17:08:30 CDT 2017 Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> powerpc: Only obtain cpu_hotplug_lock if called by rtasd
Calling arch_update_cpu_topology from a CPU hotplug state machine callback hits a deadlock because the function tries to get a read lock on cpu_hotplug_lock while the state machine still holds a write lock on it.
Since all callers of arch_update_cpu_topology except rtasd already hold cpu_hotplug_lock, this patch changes the function to use stop_machine_cpuslocked and creates a separate function for rtasd which still tries to obtain the lock.
Michael Bringmann investigated the bug and provided a detailed analysis of the deadlock on this previous RFC for an alternate solution:
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michael Bringmann <mwb@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1497996510-4032-1-git-send-email-bauerman@linux.vnet.ibm.com Link: https://patchwork.ozlabs.org/patch/771293/
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