- 14 Apr, 2009 4 commits
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Paul E. McKenney authored
This patch fixes a hierarchical-RCU performance bug located by Anton Blanchard. The problem stems from a misguided attempt to provide a work-around for jiffies-counter failure. This work-around uses a per-CPU n_rcu_pending counter, which is incremented on each call to rcu_pending(), which in turn is called from each scheduling-clock interrupt. Each CPU then treats this counter as a surrogate for the jiffies counter, so that if the jiffies counter fails to advance, the per-CPU n_rcu_pending counter will cause RCU to invoke force_quiescent_state(), which in turn will (among other things) send resched IPIs to CPUs that have thus far failed to pass through an RCU quiescent state. Unfortunately, each CPU resets only its own counter after sending a batch of IPIs. This means that the other CPUs will also (needlessly) send -another- round of IPIs, for a full N-squared set of IPIs in the worst case every three scheduler-clock ticks until the grace period finally ends. It is not reasonable for a given CPU to reset each and every n_rcu_pending for all the other CPUs, so this patch instead simply disables the jiffies-counter "training wheels", thus eliminating the excessive IPIs. Note that the jiffies-counter IPIs do not have this problem due to the fact that the jiffies counter is global, so that the CPU sending the IPIs can easily reset things, thus preventing the other CPUs from sending redundant IPIs. Note also that the n_rcu_pending counter remains, as it will continue to be used for tracing. It may also see use to update the jiffies counter, should an appropriate kick-the-jiffies-counter API appear. Located-by:
Anton Blanchard <anton@au1.ibm.com> Tested-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: anton@samba.org Cc: akpm@linux-foundation.org Cc: dipankar@in.ibm.com Cc: manfred@colorfullife.com Cc: cl@linux-foundation.org Cc: josht@linux.vnet.ibm.com Cc: schamp@sgi.com Cc: niv@us.ibm.com Cc: dvhltc@us.ibm.com Cc: ego@in.ibm.com Cc: laijs@cn.fujitsu.com Cc: rostedt@goodmis.org Cc: peterz@infradead.org Cc: penberg@cs.helsinki.fi Cc: andi@firstfloor.org Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <12396834793575-git-send-email-> Signed-off-by:
Ingo Molnar <mingo@elte.hu>
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Ingo Molnar authored
Impact: build fix for Sparc and s390 Stephen Rothwell reported that the Sparc build broke: In file included from kernel/panic.c:12: include/linux/debug_locks.h: In function '__debug_locks_off': include/linux/debug_locks.h:15: error: implicit declaration of function 'xchg' due to: 9eeba613: lockdep: warn about lockdep disabling after kernel taint There is some inconsistency between architectures about where exactly xchg() is defined. The traditional place is in system.h but the more logical point for it is in atomic.h - where most architectures (especially new ones) have it defined. These architecture also still offer it via system.h. Some, such as Sparc or s390 only have it in asm/system.h and not available via asm/atomic.h at all. Use the widest set of headers in debug_locks.h and also include asm/system.h. Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20090414144317.026498df.sfr@canb.auug.org.au> Signed-off-by:
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Linus Torvalds authored
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: tomoyo: version bump to 2.2.0. tomoyo: add Documentation/tomoyo.txt
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Linus Torvalds authored
We ended up incorrectly using '&cur' instead of '&readin' in the work_on_cpu() -> smp_call_function_single() transformation in commit 01599fca ("cpufreq: use smp_call_function_[single|many]() in acpi-cpufreq.c"). Andrew explains: "OK, the acpi tree went and had conflicting changes merged into it after I'd written the patch and it appears that I incorrectly reverted part of 18b2646f while fixing the resulting rejects. Switching it to `readin' looks correct." Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 13 Apr, 2009 36 commits
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Tetsuo Handa authored
Signed-off-by:
Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by:
Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by:
James Morris <jmorris@namei.org>
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Tetsuo Handa authored
Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xenLinus Torvalds authored
* 'for-rc1/xen/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: xen: add FIX_TEXT_POKE to fixmap xen: honour VCPU availability on boot xen: clean up gate trap/interrupt constants xen: set _PAGE_NX in __supported_pte_mask before pagetable construction xen: resume interrupts before system devices. xen/mmu: weaken flush_tlb_other test xen/mmu: some early pagetable cleanups Xen: Add virt_to_pfn helper function x86-64: remove PGE from must-have feature list xen: mask XSAVE from cpuid NULL noise: arch/x86/xen/smp.c xen: remove xen_load_gdt debug xen: make xen_load_gdt simpler xen: clean up xen_load_gdt xen: split construction of p2m mfn tables from registration xen: separate p2m allocation from setting xen: disable preempt for leave_lazy_mmu
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Jean Delvare authored
The edac-core driver includes code which assumes that the work_struct which is included in every delayed_work is the first member of that structure. This is currently the case but might change in the future, so use to_delayed_work() instead, which doesn't make such an assumption. linux-2.6.30-rc1 has the to_delayed_work() function that will allow this patch to work Signed-off-by:
Jean Delvare <khali@linux-fr.org> Signed-off-by:
Doug Thompson <dougthompson@xmission.com> Signed-off-by:
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Jeff Haran authored
Fix the edac local pci_write_bits32 to properly note the 'escape' mask if all ones in a 32-bit word. Currently no consumer of this function uses that mask, so there is no danger to existing code. Signed-off-by:
Jeff Haran <jharan@Brocade.COM> Signed-off-by:
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Robin Holt authored
Introduce xpc_arch_ops and eliminate numerous individual global definitions. Signed-off-by:
Robin Holt <holt@sgi.com> Cc: Dean Nelson <dcn@sgi.com> Signed-off-by:
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Robin Holt authored
sgi-xpc has a window of failure where an open message can be sent and a subsequent data message can get lost. We have added a new message (opencomplete) which closes that window. Signed-off-by:
Dean Nelson <dcn@sgi.com> Signed-off-by:
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Robin Holt authored
The heartbeat timeout functionality in sgi-xpc is currently not trained to the connection time. If a connection is made and the code is in the last polling window prior to doing a timeout, the next polling window will see the heartbeat as unchanged and initiate a no-heartbeat disconnect. Signed-off-by:
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Robin Holt authored
Dean has moved on to other work. His responsibilities for XP/XPC/XPNET have been handed to me. Signed-off-by:
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Shen Feng authored
Use the default mountpoint of debugfs in the pktcdvd ABI. Signed-off-by:
Shen Feng <shen@cn.fujitsu.com> Cc: <balagi@justmail.de> Signed-off-by:
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Bharata B Rao authored
The description about various statistics from memory.stat is not accurate and confusing at times. Correct this along with a few other minor cleanups. Signed-off-by:
Bharata B Rao <bharata@linux.vnet.ibm.com> Acked-by:
Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by:
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Yang Hongyang authored
This is the second go through of the old DMA_nBIT_MASK macro,and there're not so many of them left,so I put them into one patch.I hope this is the last round. After this the definition of the old DMA_nBIT_MASK macro could be removed. Signed-off-by:
Yang Hongyang <yanghy@cn.fujitsu.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Tony Lindgren <tony@atomide.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Greg KH <greg@kroah.com> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Jan Kara authored
If two writers allocating blocks to file race with each other (e.g. because writepages races with ordinary write or two writepages race with each other), ext2_getblock() can be called on the same inode in parallel. Before we are going to allocate new blocks, we have to recheck the block chain we have obtained so far without holding truncate_mutex. Otherwise we could overwrite the indirect block pointer set by the other writer leading to data loss. The below test program by Ying is able to reproduce the data loss with ext2 on in BRD in a few minutes if the machine is under memory pressure: long kMemSize = 50 << 20; int kPageSize = 4096; int main(int argc, char **argv) { int status; int count = 0; int i; char *fname = "/mnt/test.mmap"; char *mem; unlink(fname); int fd = open(fname, O_CREAT | O_EXCL | O_RDWR, 0600); status = ftruncate(fd, kMemSize); mem = mmap(0, kMemSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); // Fill the memory with 1s. memset(mem, 1, kMemSize); sleep(2); for (i = 0; i < kMemSize; i++) { int byte_good = mem[i] != 0; if (!byte_good && ((i % kPageSize) == 0)) { //printf("%d ", i / kPageSize); count++; } } munmap(mem, kMemSize); close(fd); unlink(fname); if (count > 0) { printf("Running %d bad page\n", count); return 1; } return 0; } Cc: Ying Han <yinghan@google.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:Jan Kara <jack@suse.cz> Cc: Mingming Cao <cmm@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Signed-off-by:
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Hugh Dickins authored
SHMEM_MAX_BYTES was derived from the maximum size of its triple-indirect swap vector, forgetting to take the MAX_LFS_FILESIZE limit into account. Never mind 256kB pages, even 8kB pages on 32-bit kernels allowed files to grow slightly bigger than that supposed maximum. Fix this by using the min of both (at build time not run time). And it happens that this calculation is good as far as 8MB pages on 32-bit or 16MB pages on 64-bit: though SHMSWP_MAX_INDEX gets truncated before that, it's truncated to such large numbers that we don't need to care. [akpm@linux-foundation.org: it needs pagemap.h] [akpm@linux-foundation.org: fix sparc64 min() warnings] Signed-off-by:
Hugh Dickins <hugh@veritas.com> Cc: Yuri Tikhonov <yur@emcraft.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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Yuri Tikhonov authored
Fix a division by zero which we have in shmem_truncate_range() and shmem_unuse_inode() when using big PAGE_SIZE values (e.g. 256kB on ppc44x). With 256kB PAGE_SIZE, the ENTRIES_PER_PAGEPAGE constant becomes too large (0x1.0000.0000) on a 32-bit kernel, so this patch just changes its type from 'unsigned long' to 'unsigned long long'. Hugh: reverted its unsigned long longs in shmem_truncate_range() and shmem_getpage(): the pagecache index cannot be more than an unsigned long, so the divisions by zero occurred in unreached code. It's a pity we need any ULL arithmetic here, but I found no pretty way to avoid it. Signed-off-by:
Yuri Tikhonov <yur@emcraft.com> Signed-off-by:
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Stefan Husemann authored
Support the Intel 854 Chipset in fbdev. We test and use the patch on a Thomson IP1101 IPTV-Box. On the VGA-Port we get a normal signal. Here is the link to the Mambux-Project: http://www.mambux.de Cc: Keith Packard <keithp@keithp.com> Cc: Dave Airlie <airlied@linux.ie> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Signed-off-by:
Stefan Husemann <shusemann@googlemail.com> Signed-off-by:
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Michael Ellerman authored
I'm sure everyone knows this, but I didn't, so I googled it, and found a nice explanation from Linus. Might be worth sticking in Documentation. Signed-off-by:
Michael Ellerman <michael@ellerman.id.au> Signed-off-by:
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KAMEZAWA Hiroyuki authored
mm/memcontrol.c:318: warning: `mem_cgroup_is_obsolete' defined but not used [akpm@linux-foundation.org: simplify as suggested by Balbir] Signed-off-by:
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Andi Kleen authored
Impact: cleanup, fix Clean up sys_shutdown() exit path. Factor out common code. Return correct error code instead of always 0 on failure. Signed-off-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
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Geert Uytterhoeven authored
| drivers/misc/eeprom/at25.c:358: warning: assignment from incompatible pointer type Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: Kevin Hilman <khilman@deeprootsystems.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by:
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Geert Uytterhoeven authored
| drivers/misc/eeprom/at24.c:508: warning: assignment from incompatible pointer type Signed-off-by:
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Jan Kara authored
Update information about locking in JBD revoke code. Reported-by: Lin Tan <tammy000@gmail.com>. Signed-off-by:
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Andy Grover authored
While better than get_user_pages(), the usage of gupf(), especially the return values and the fact that it can potentially only partially pin the range, warranted some documentation. Signed-off-by:
Andy Grover <andy.grover@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:
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Randy Robertson authored
Change cb6ff208 ("NOMMU: Support XIP on initramfs") seems to have broken booting from initramfs with /sbin/init being a hardlink. It seems like the logic required for XIP on nommu, i.e. ftruncate to reported cpio header file size (body_len) is broken for hardlinks, which have a reported size of 0, and the truncate thus nukes the contents of the file (in my case busybox), making boot impossible and ending with runaway loop modprobe binfmt-0000 - and of course 0000 is not a valid binary format. My fix is to only call ftruncate if size is non-zero which fixes things for me, but I'm not certain whether this will break XIP for those files on nommu systems, although I would guess not. Signed-off-by:
Randy Robertson <rmrobert@vmware.com> Acked-by:
David Howells <dhowells@redhat.com> Acked-by:
Paul Mundt <lethal@linux-sh.org> Acked-by:
H. Peter Anvin <hpa@zytor.com> Signed-off-by:
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Oleg Nesterov authored
Pointed out by Roland. The bug was recently introduced by me in "forget_original_parent: split out the un-ptrace part", commit 39c626ae. Since that patch we have a window after exit_ptrace() drops tasklist and before forget_original_parent() takes it again. In this window the child can do ptrace(PTRACE_TRACEME) and nobody can untrace this child after that. Change ptrace_traceme() to not attach to the exiting ->real_parent. We don't report the error in this case, we pretend we attach right before ->real_parent calls exit_ptrace() which should untrace us anyway. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
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Jean Delvare authored
Signed-off-by:
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David Howells authored
Do a bit of reformatting on the Unevictable-LRU documentation. Signed-off-by:
Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
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David Howells authored
Point the UNEVICTABLE_LRU config option at the documentation describing the option. Signed-off-by:
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Huang Weiyi authored
Remove duplicated #include in drivers/char/sysrq.c. Signed-off-by:
Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by:
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Joe Perches authored
commit ddb53d48 ("fbdev: remove cyblafb driver") removed drivers/video/cyblafb.c, but not its .h file Signed-off-by:
Joe Perches <joe@perches.com> Cc: Krzysztof Helt <krzysztof.h1@wp.pl> Cc: "Jani Monoses" <jani@ubuntu.com> Signed-off-by:
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Andrea Righi authored
After the introduction of resource counters hierarchies (28dbc4b6) the prototypes of res_counter_init() and res_counter_charge() have been changed. Keep the documentation consistent with the actual function prototypes. Signed-off-by:
Andrea Righi <righi.andrea@gmail.com> Cc: Paul Menage <menage@google.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by:
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David Brownell authored
The "simplify spi_write_then_read()" patch included two regressions from the 2.6.27 behaviors: - The data it wrote out during the (full duplex) read side of the transfer was not zeroed. - It fails completely on half duplex hardware, such as Microwire and most "3-wire" SPI variants. So, revert that patch. A revised version should be submitted at some point, which can get the speedup on standard hardware (full duplex) without breaking on less-capable half-duplex stuff. Signed-off-by:
David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> [2.6.28.x, 2.6.29.x] Signed-off-by:
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Andi Kleen authored
Impact: (nearly) trivial The patch commit da654b74 Author: Srinivasa Ds <srinivasa@in.ibm.com> Date: Tue Sep 23 15:23:52 2008 +0530 signals: demultiplexing SIGTRAP signal forgot to update the NSIGTRAP define in asm-generic/siginfo.h to the new number of sigtrap subcodes. Nothing in the tree seems to use it, but presumably something in user space might. So update it. Cc: Srinivasa Ds <srinivasa@in.ibm.com> Signed-off-by:
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Krzysztof Helt authored
Do not allow modes with unsupported pixel depth. Otherwise, one can hang a computer by setting incorrect value with fbset command. Signed-off-by:
Krzysztof Helt <krzysztof.h1@wp.pl> Signed-off-by:
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Randy Dunlap authored
Fix filemap.c kernel-doc warnings: Warning(mm/filemap.c:575): No description found for parameter 'page' Warning(mm/filemap.c:575): No description found for parameter 'waiter' Signed-off-by:
Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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Eric Sandeen authored
Include <linux/types.h> in fiemap.h. Sam Ravnborg pointed out that this was missing in this newly-exported header which uses the __u32 and __u64 types. Signed-off-by:
Eric Sandeen <sandeen@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by:
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