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path: root/arch/parisc/include/asm/processor.h
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2014-05-15parisc,metag: Do not hardcode maximum userspace stack sizeHelge Deller
This patch affects only architectures where the stack grows upwards (currently parisc and metag only). On those do not hardcode the maximum initial stack size to 1GB for 32-bit processes, but make it configurable via a config option. The main problem with the hardcoded stack size is, that we have two memory regions which grow upwards: stack and heap. To keep most of the memory available for heap in a flexmap memory layout, it makes no sense to hard allocate up to 1GB of the memory for stack which can't be used as heap then. This patch makes the stack size for 32-bit processes configurable and uses 80MB as default value which has been in use during the last few years on parisc and which hasn't showed any problems yet. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: linux-parisc@vger.kernel.org Cc: linux-metag@vger.kernel.org Cc: John David Anglin <dave.anglin@bell.net>
2014-05-15metag: Reduce maximum stack size to 256MBJames Hogan
Specify the maximum stack size for arches where the stack grows upward (parisc and metag) in asm/processor.h rather than hard coding in fs/exec.c so that metag can specify a smaller value of 256MB rather than 1GB. This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased beyond a safe value by root. E.g. when starting a process after running "ulimit -H -s unlimited" it will then attempt to use a stack size of the maximum 1GB which is far too big for metag's limited user virtual address space (stack_top is usually 0x3ffff000): BUG: failure at fs/exec.c:589/shift_arg_pages()! Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: linux-parisc@vger.kernel.org Cc: linux-metag@vger.kernel.org Cc: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # only needed for >= v3.9 (arch/metag)
2014-02-02parisc: add flexible mmap memory layout supportHelge Deller
Add support for the flexible mmap memory layout (as described in http://lwn.net/Articles/91829). This is especially very interesting on parisc since we currently only support 32bit userspace (even with a 64bit Linux kernel). Signed-off-by: Helge Deller <deller@gmx.de>
2013-05-24parisc: fix irq stack on UP and SMPHelge Deller
The logic to detect if the irq stack was already in use with raw_spin_trylock() is wrong, because it will generate a "trylock failure on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y. arch_spin_trylock() can't be used either since in the CONFIG_SMP=n case no atomic protection is given and we are reentrant here. A mutex didn't worked either and brings more overhead by turning off interrupts. So, let's use the fastest path for parisc which is the ldcw instruction. Counting how often the irq stack was used is pretty useless, so just drop this piece of code. Signed-off-by: Helge Deller <deller@gmx.de>
2013-05-11parisc: implement irq stacks - part 2 (v2)Helge Deller
This patch fixes few build issues which were introduced with the last irq stack patch, e.g. the combination of stack overflow check and irq stack. Furthermore we now do proper locking and change the irq bh handler to use the irq stack as well. In /proc/interrupts one now can monitor how huge the irq stack has grown and how often it was preferred over the kernel stack. IRQ stacks are now enabled by default just to make sure that we not overflow the kernel stack by accident. Signed-off-by: Helge Deller <deller@gmx.de>
2013-05-07parisc: more irq statistics in /proc/interruptsHelge Deller
Add framework and initial values for more fine grained statistics in /proc/interrupts. Signed-off-by: Helge Deller <deller@gmx.de>
2013-05-07parisc: implement irq stacksHelge Deller
Default kernel stack size on parisc is 16k. During tests we found that the kernel stack can easily grow beyond 13k, which leaves 3k left for irq processing. This patch adds the possibility to activate an additional stack of 16k per CPU which is being used during irq processing. This implementation does not yet uses this irq stack for the irq bh handler. The assembler code for call_on_stack was heavily cleaned up by John David Anglin. CC: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de>
2012-11-28kill stray kernel_thread() garbageAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-16fork: move the real prepare_to_copy() users to arch_dup_task_struct()Suresh Siddha
Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov <oleg@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Chris Zankel <chris@zankel.net> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-03-28Disintegrate asm/system.h for PA-RISCDavid Howells
Disintegrate asm/system.h for PA-RISC. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-parisc@vger.kernel.org
2012-01-12parisc, exec: remove redundant set_fs(USER_DS)Mathias Krause
The address limit is already set in flush_old_exec() so those calls to set_fs(USER_DS) are redundant. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-03parisc: add task_pt_regs macroKyle McMartin
needed for perf_counters. Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
2009-01-05parisc: Replace NR_CPUS in parisc codeHelge Deller
parisc: Replace most arrays sized by NR_CPUS with percpu variables. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
2008-10-10parisc: move include/asm-parisc to arch/parisc/include/asmKyle McMartin