- 22 7月, 2011 19 次提交
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由 Rusty Russell 提交于
We were blatting too much of the register. Linux didn't care, but in theory it might. Reported-by: NJonas Maebe <jonas.maebe@elis.ugent.be> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Adrian Knoth 提交于
The comment is outdated, wikipedia now has six translations of the cpuid page. Signed-off-by: NAdrian Knoth <adi@drcomp.erfurt.thur.de> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Adrian Knoth 提交于
This patch fixes three typos I've accidentally spotted. Signed-off-by: NAdrian Knoth <adi@drcomp.erfurt.thur.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (one was already fixed)
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由 Rusty Russell 提交于
Also removes a long-unused #define and an extraneous semicolon. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Rusty Russell 提交于
We used to notify the Host every time we updated a device's status. However, it only really needs to know when we're resetting the device, or failed to initialize it, or when we've finished our feature negotiation. In particular, we used to wait for VIRTIO_CONFIG_S_DRIVER_OK in the status byte before starting the device service threads. But this corresponds to the successful finish of device initialization, which might (like virtio_blk's partition scanning) use the device. So we had a hack, if they used the device before we expected we started the threads anyway. Now we hook into the finalize_features hook in the Guest: at that point we tell the Launcher that it can rely on the features we have acked. On the Launcher side, we look at the status at that point, and start servicing the device. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Rusty Russell 提交于
Now we no longer use vmcall, we don't need to rewrite it in the Guest. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Rusty Russell 提交于
We switch back from using vmcall in 091ebf07 because it was unreliable under kvm, but I missed one (rarely-used) place. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Rusty Russell 提交于
The Host used to create some page tables for the Guest to use at the top of Guest memory; it would then tell the Guest where this was. In particular, it created linear mappings for 0 and 0xC0000000 addresses because lguest used to switch to its real page tables quite late in boot. However, since d50d8fe1 Linux initialized boot page tables in head_32.S even before the "are we lguest?" boot jump. So, now we can simplify things: the Host pagetable code assumes 1:1 linear mapping until it first calls the LHCALL_NEW_PGTABLE hypercall, which we now do before we reach C code. This also means that the Host doesn't need to know anything about the Guest's PAGE_OFFSET. (Non-Linux guests might not even have such a thing). Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Sakari Ailus 提交于
Do not exit on some non-fatal errors: - writev() fails in net_output(). The result is a lost packet or packets. - writev() fails in console_output(). The result is partially lost console output. - readv() fails in net_input(). The result is a lost packet or packets. Rather than bringing the guest down, this patch ignores e.g. an allocation failure on the host side. Example: lguest: page allocation failure. order:4, mode:0x4d0 Pid: 4045, comm: lguest Tainted: G W 2.6.36 #1 Call Trace: [<c138d614>] ? printk+0x18/0x1c [<c106a4e2>] __alloc_pages_nodemask+0x4d2/0x570 [<c1087954>] cache_alloc_refill+0x2a4/0x4d0 [<c1305149>] ? __netif_receive_skb+0x189/0x270 [<c1087c5a>] __kmalloc+0xda/0xf0 [<c12fffa5>] __alloc_skb+0x55/0x100 [<c1305519>] ? net_rx_action+0x79/0x100 [<c12fafed>] sock_alloc_send_pskb+0x18d/0x280 [<c11fda25>] ? _copy_from_user+0x35/0x130 [<c13010b6>] ? memcpy_fromiovecend+0x56/0x80 [<c12a74dc>] tun_chr_aio_write+0x1cc/0x500 [<c108a125>] do_sync_readv_writev+0x95/0xd0 [<c11fda25>] ? _copy_from_user+0x35/0x130 [<c1089fa8>] ? rw_copy_check_uvector+0x58/0x100 [<c108a7bc>] do_readv_writev+0x9c/0x1d0 [<c12a7310>] ? tun_chr_aio_write+0x0/0x500 [<c108a93a>] vfs_writev+0x4a/0x60 [<c108aa21>] sys_writev+0x41/0x80 [<c138f061>] syscall_call+0x7/0xb Mem-Info: DMA per-cpu: CPU 0: hi: 0, btch: 1 usd: 0 Normal per-cpu: CPU 0: hi: 186, btch: 31 usd: 0 HighMem per-cpu: CPU 0: hi: 186, btch: 31 usd: 0 active_anon:134651 inactive_anon:50543 isolated_anon:0 active_file:96881 inactive_file:132007 isolated_file:0 unevictable:0 dirty:3 writeback:0 unstable:0 free:91374 slab_reclaimable:6300 slab_unreclaimable:2802 mapped:2281 shmem:9 pagetables:330 bounce:0 DMA free:3524kB min:64kB low:80kB high:96kB active_anon:0kB inactive_anon:8kB active_file:8760kB inactive_file:2760kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15868kB mlocked:0kB dirty:0kB writeback:0kB mapped:16kB shmem:0kB slab_reclaimable:88kB slab_unreclaimable:148kB kernel_stack:40kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 865 2016 2016 Normal free:150100kB min:3728kB low:4660kB high:5592kB active_anon:6224kB inactive_anon:15772kB active_file:324084kB inactive_file:325944kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:885944kB mlocked:0kB dirty:12kB writeback:0kB mapped:1520kB shmem:0kB slab_reclaimable:25112kB slab_unreclaimable:11060kB kernel_stack:1888kB pagetables:1320kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 9207 9207 HighMem free:211872kB min:512kB low:1752kB high:2992kB active_anon:532380kB inactive_anon:186392kB active_file:54680kB inactive_file:199324kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:1178504kB mlocked:0kB dirty:0kB writeback:0kB mapped:7588kB shmem:36kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 DMA: 3*4kB 65*8kB 35*16kB 18*32kB 11*64kB 9*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3524kB Normal: 35981*4kB 344*8kB 158*16kB 28*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 150100kB HighMem: 5732*4kB 5462*8kB 2826*16kB 1598*32kB 84*64kB 10*128kB 7*256kB 1*512kB 1*1024kB 1*2048kB 9*4096kB = 211872kB 231237 total pagecache pages 2340 pages in swap cache Swap cache stats: add 160060, delete 157720, find 189017/194106 Free swap = 4179840kB Total swap = 4194300kB 524271 pages RAM 296946 pages HighMem 5668 pages reserved 867664 pages shared 82155 pages non-shared Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Linus Torvalds 提交于
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git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb由 Linus Torvalds 提交于
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: sparc,kgdbts: fix compile regression with kgdb test suite
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由 Jason Wessel 提交于
Commit 63ab25eb (kgdbts: unify/generalize gdb breakpoint adjustment) introduced a compile regression on sparc. kgdbts.c: In function 'check_and_rewind_pc': kgdbts.c:307: error: implicit declaration of function 'instruction_pointer_set' Simply add the correct macro definition for instruction pointer on the Sparc architecture. Signed-off-by: NJason Wessel <jason.wessel@windriver.com> Acked-by: NMike Frysinger <vapier@gentoo.org> Acked-by: NDavid S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6由 Linus Torvalds 提交于
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: CIFS: Fix wrong length in cifs_iovec_read
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由 Linus Torvalds 提交于
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Make Dell Latitude E6420 use reboot=pci x86: Make Dell Latitude E5420 use reboot=pci
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由 H. Peter Anvin 提交于
Yet another variant of the Dell Latitude series which requires reboot=pci. From the E5420 bug report by Daniel J Blueman: > The E6420 is affected also (same platform, different casing and > features), which provides an external confirmation of the issue; I can > submit a patch for that later or include it if you prefer: > http://linux.koolsolutions.com/2009/08/04/howto-fix-linux-hangfreeze-during-reboots-and-restarts/Reported-by: NDaniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: NH. Peter Anvin <hpa@zytor.com> Cc: <stable@kernel.org>
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由 Daniel J Blueman 提交于
Rebooting on the Dell E5420 often hangs with the keyboard or ACPI methods, but is reliable via the PCI method. [ hpa: this was deferred because we believed for a long time that the recent reshuffling of the boot priorities in commit 660e34ce fixed this platform. Unfortunately that turned out to be incorrect. ] Signed-off-by: NDaniel J Blueman <daniel.blueman@gmail.com> Link: http://lkml.kernel.org/r/1305248699-2347-1-git-send-email-daniel.blueman@gmail.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com> Cc: <stable@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6由 Linus Torvalds 提交于
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6: drm/i915: Fix unfenced alignment on pre-G33 hardware drm/i915: Add quirk to disable SSC on Lenovo U160 LVDS
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由 Linus Torvalds 提交于
It seems to hurt performance in real life. Yes, the inode will be used later, but the conditional doesn't seem to predict all that well (negative dentries are not uncommon) and it looks like the cost of prefetching is simply higher than depending on the cache doing the right thing. As usual. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Jan Beulich 提交于
The compiler, at least for ix86 and m68k, validly warns that the comparison: next <= (loff_t)-1 is always true (and it's always true also for x86-64 and probably all other arches - as long as pgoff_t isn't wider than loff_t). The intention appears to be to avoid wrapping of "next", so rather than eliminating the pointless comparison, fix the loop to indeed get exited when "next" would otherwise wrap. On m68k the following warning is observed: fs/fscache/page.c: In function '__fscache_uncache_all_inode_pages': fs/fscache/page.c:979: warning: comparison is always false due to limited range of data type Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org> Reported-by: NJan Beulich <jbeulich@novell.com> Signed-off-by: NJan Beulich <jbeulich@novell.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Cc: Suresh Jayaraman <sjayaraman@suse.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 21 7月, 2011 12 次提交
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由 Pavel Shilovsky 提交于
Signed-off-by: NPavel Shilovsky <piastryyy@gmail.com> Reviewed-by: NJeff Layton <jlayton@redhat.com> Signed-off-by: NSteve French <sfrench@us.ibm.com>
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由 Linus Torvalds 提交于
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: signal: align __lock_task_sighand() irq disabling and RCU softirq,rcu: Inform RCU of irq_exit() activity sched: Add irq_{enter,exit}() to scheduler_ipi() rcu: protect __rcu_read_unlock() against scheduler-using irq handlers rcu: Streamline code produced by __rcu_read_unlock() rcu: Fix RCU_BOOST race handling current->rcu_read_unlock_special rcu: decrease rcu_report_exp_rnp coupling with scheduler
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由 Linus Torvalds 提交于
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Avoid creating superfluous NUMA domains on non-NUMA systems sched: Allow for overlapping sched_domain spans sched: Break out cpu_power from the sched_group structure
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由 Linus Torvalds 提交于
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86. reboot: Make Dell Latitude E6320 use reboot=pci x86, doc only: Correct real-mode kernel header offset for init_size x86: Disable AMD_NUMA for 32bit for now
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由 Ingo Molnar 提交于
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/urgent
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由 Paul E. McKenney 提交于
The __lock_task_sighand() function calls rcu_read_lock() with interrupts and preemption enabled, but later calls rcu_read_unlock() with interrupts disabled. It is therefore possible that this RCU read-side critical section will be preempted and later RCU priority boosted, which means that rcu_read_unlock() will call rt_mutex_unlock() in order to deboost itself, but with interrupts disabled. This results in lockdep splats, so this commit nests the RCU read-side critical section within the interrupt-disabled region of code. This prevents the RCU read-side critical section from being preempted, and thus prevents the attempt to deboost with interrupts disabled. It is quite possible that a better long-term fix is to make rt_mutex_unlock() disable irqs when acquiring the rt_mutex structure's ->wait_lock. Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
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由 Peter Zijlstra 提交于
The rcu_read_unlock_special() function relies on in_irq() to exclude scheduler activity from interrupt level. This fails because exit_irq() can invoke the scheduler after clearing the preempt_count() bits that in_irq() uses to determine that it is at interrupt level. This situation can result in failures as follows: $task IRQ SoftIRQ rcu_read_lock() /* do stuff */ <preempt> |= UNLOCK_BLOCKED rcu_read_unlock() --t->rcu_read_lock_nesting irq_enter(); /* do stuff, don't use RCU */ irq_exit(); sub_preempt_count(IRQ_EXIT_OFFSET); invoke_softirq() ttwu(); spin_lock_irq(&pi->lock) rcu_read_lock(); /* do stuff */ rcu_read_unlock(); rcu_read_unlock_special() rcu_report_exp_rnp() ttwu() spin_lock_irq(&pi->lock) /* deadlock */ rcu_read_unlock_special(t); Ed can simply trigger this 'easy' because invoke_softirq() immediately does a ttwu() of ksoftirqd/# instead of doing the in-place softirq stuff first, but even without that the above happens. Cure this by also excluding softirqs from the rcu_read_unlock_special() handler and ensuring the force_irqthreads ksoftirqd/# wakeup is done from full softirq context. [ Alternatively, delaying the ->rcu_read_lock_nesting decrement until after the special handling would make the thing more robust in the face of interrupts as well. And there is a separate patch for that. ] Cc: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: NEd Tomlinson <edt@aei.ca> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
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由 Peter Zijlstra 提交于
Ensure scheduler_ipi() calls irq_{enter,exit} when it does some actual work. Traditionally we never did any actual work from the resched IPI and all magic happened in the return from interrupt path. Now that we do do some work, we need to ensure irq_{enter,exit} are called so that we don't confuse things. This affects things like timekeeping, NO_HZ and RCU, basically everything with a hook in irq_enter/exit. Explicit examples of things going wrong are: sched_clock_cpu() -- has a callback when leaving NO_HZ state to take a new reading from GTOD and TSC. Without this callback, time is stuck in the past. RCU -- needs in_irq() to work in order to avoid some nasty deadlocks Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
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由 Paul E. McKenney 提交于
The addition of RCU read-side critical sections within runqueue and priority-inheritance lock critical sections introduced some deadlock cycles, for example, involving interrupts from __rcu_read_unlock() where the interrupt handlers call wake_up(). This situation can cause the instance of __rcu_read_unlock() invoked from interrupt to do some of the processing that would otherwise have been carried out by the task-level instance of __rcu_read_unlock(). When the interrupt-level instance of __rcu_read_unlock() is called with a scheduler lock held from interrupt-entry/exit situations where in_irq() returns false, deadlock can result. This commit resolves these deadlocks by using negative values of the per-task ->rcu_read_lock_nesting counter to indicate that an instance of __rcu_read_unlock() is in flight, which in turn prevents instances from interrupt handlers from doing any special processing. This patch is inspired by Steven Rostedt's earlier patch that similarly made __rcu_read_unlock() guard against interrupt-mediated recursion (see https://lkml.org/lkml/2011/7/15/326), but this commit refines Steven's approach to avoid the need for preemption disabling on the __rcu_read_unlock() fastpath and to also avoid the need for manipulating a separate per-CPU variable. This patch avoids need for preempt_disable() by instead using negative values of the per-task ->rcu_read_lock_nesting counter. Note that nested rcu_read_lock()/rcu_read_unlock() pairs are still permitted, but they will never see ->rcu_read_lock_nesting go to zero, and will therefore never invoke rcu_read_unlock_special(), thus preventing them from seeing the RCU_READ_UNLOCK_BLOCKED bit should it be set in ->rcu_read_unlock_special. This patch also adds a check for ->rcu_read_unlock_special being negative in rcu_check_callbacks(), thus preventing the RCU_READ_UNLOCK_NEED_QS bit from being set should a scheduling-clock interrupt occur while __rcu_read_unlock() is exiting from an outermost RCU read-side critical section. Of course, __rcu_read_unlock() can be preempted during the time that ->rcu_read_lock_nesting is negative. This could result in the setting of the RCU_READ_UNLOCK_BLOCKED bit after __rcu_read_unlock() checks it, and would also result it this task being queued on the corresponding rcu_node structure's blkd_tasks list. Therefore, some later RCU read-side critical section would enter rcu_read_unlock_special() to clean up -- which could result in deadlock if that critical section happened to be in the scheduler where the runqueue or priority-inheritance locks were held. This situation is dealt with by making rcu_preempt_note_context_switch() check for negative ->rcu_read_lock_nesting, thus refraining from queuing the task (and from setting RCU_READ_UNLOCK_BLOCKED) if we are already exiting from the outermost RCU read-side critical section (in other words, we really are no longer actually in that RCU read-side critical section). In addition, rcu_preempt_note_context_switch() invokes rcu_read_unlock_special() to carry out the cleanup in this case, which clears out the ->rcu_read_unlock_special bits and dequeues the task (if necessary), in turn avoiding needless delay of the current RCU grace period and needless RCU priority boosting. It is still illegal to call rcu_read_unlock() while holding a scheduler lock if the prior RCU read-side critical section has ever had either preemption or irqs enabled. However, the common use case is legal, namely where then entire RCU read-side critical section executes with irqs disabled, for example, when the scheduler lock is held across the entire lifetime of the RCU read-side critical section. Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
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由 Peter Zijlstra 提交于
When creating sched_domains, stop when we've covered the entire target span instead of continuing to create domains, only to later find they're redundant and throw them away again. This avoids single node systems from touching funny NUMA sched_domain creation code and reduces the risks of the new SD_OVERLAP code. Requested-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Anton Blanchard <anton@samba.org> Cc: mahesh@linux.vnet.ibm.com Cc: benh@kernel.crashing.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1311180177.29152.57.camel@twinsSigned-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
In order to prepare for non-unique sched_groups per domain, we need to carry the cpu_power elsewhere, so put a level of indirection in. Reported-and-tested-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 20 7月, 2011 9 次提交
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: ceph: fix file mode calculation
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc由 Linus Torvalds 提交于
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc: davinci: DM365 EVM: fix video input mux bits ARM: davinci: Check for NULL return from irq_alloc_generic_chip arm: davinci: Fix low level gpio irq handlers' argument
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由 Shaohua Li 提交于
I'm running a workload which triggers a lot of swap in a machine with 4 nodes. After I kill the workload, I found a kswapd livelock. Sometimes kswapd3 or kswapd2 are keeping running and I can't access filesystem, but most memory is free. This looks like a regression since commit 08951e54 ("mm: vmscan: correct check for kswapd sleeping in sleeping_prematurely"). Node 2 and 3 have only ZONE_NORMAL, but balance_pgdat() will return 0 for classzone_idx. The reason is end_zone in balance_pgdat() is 0 by default, if all zones have watermark ok, end_zone will keep 0. Later sleeping_prematurely() always returns true. Because this is an order 3 wakeup, and if classzone_idx is 0, both balanced_pages and present_pages in pgdat_balanced() are 0. We add a special case here. If a zone has no page, we think it's balanced. This fixes the livelock. Signed-off-by: NShaohua Li <shaohua.li@intel.com> Acked-by: NMel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Akinobu Mita 提交于
Assume that /sys/kernel/debug/dummy64 is debugfs file created by debugfs_create_x64(). # cd /sys/kernel/debug # echo 0x1234567812345678 > dummy64 # cat dummy64 0x0000000012345678 # echo 0x80000000 > dummy64 # cat dummy64 0xffffffff80000000 A value larger than INT_MAX cannot be written to the debugfs file created by debugfs_create_u64 or debugfs_create_x64 on 32bit machine. Because simple_attr_write() uses simple_strtol() for the conversion. To fix this, use simple_strtoll() instead. Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6由 Linus Torvalds 提交于
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: vfs: fix race in rcu lookup of pruned dentry Fix cifs_get_root() [ Edited the last commit to get rid of a 'unused variable "seq"' warning due to Al editing the patch. - Linus ]
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由 Linus Torvalds 提交于
Don't update *inode in __follow_mount_rcu() until we'd verified that there is mountpoint there. Kudos to Hugh Dickins for catching that one in the first place and eventually figuring out the solution (and catching a braino in the earlier version of patch). Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Paul E. McKenney 提交于
Given some common flag combinations, particularly -Os, gcc will inline rcu_read_unlock_special() despite its being in an unlikely() clause. Use noinline to prohibit this misoptimization. In addition, move the second barrier() in __rcu_read_unlock() so that it is not on the common-case code path. This will allow the compiler to generate better code for the common-case path through __rcu_read_unlock(). Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
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由 Paul E. McKenney 提交于
The RCU_BOOST commits for TREE_PREEMPT_RCU introduced an other-task write to a new RCU_READ_UNLOCK_BOOSTED bit in the task_struct structure's ->rcu_read_unlock_special field, but, as noted by Steven Rostedt, without correctly synchronizing all accesses to ->rcu_read_unlock_special. This could result in bits in ->rcu_read_unlock_special being spuriously set and cleared due to conflicting accesses, which in turn could result in deadlocks between the rcu_node structure's ->lock and the scheduler's rq and pi locks. These deadlocks would result from RCU incorrectly believing that the just-ended RCU read-side critical section had been preempted and/or boosted. If that RCU read-side critical section was executed with either rq or pi locks held, RCU's ensuing (incorrect) calls to the scheduler would cause the scheduler to attempt to once again acquire the rq and pi locks, resulting in deadlock. More complex deadlock cycles are also possible, involving multiple rq and pi locks as well as locks from multiple rcu_node structures. This commit fixes synchronization by creating ->rcu_boosted field in task_struct that is accessed and modified only when holding the ->lock in the rcu_node structure on which the task is queued (on that rcu_node structure's ->blkd_tasks list). This results in tasks accessing only their own current->rcu_read_unlock_special fields, making unsynchronized access once again legal, and keeping the rcu_read_unlock() fastpath free of atomic instructions and memory barriers. The reason that the rcu_read_unlock() fastpath does not need to access the new current->rcu_boosted field is that this new field cannot be non-zero unless the RCU_READ_UNLOCK_BLOCKED bit is set in the current->rcu_read_unlock_special field. Therefore, rcu_read_unlock() need only test current->rcu_read_unlock_special: if that is zero, then current->rcu_boosted must also be zero. This bug does not affect TINY_PREEMPT_RCU because this implementation of RCU accesses current->rcu_read_unlock_special with irqs disabled, thus preventing races on the !SMP systems that TINY_PREEMPT_RCU runs on. Maybe-reported-by: NDave Jones <davej@redhat.com> Maybe-reported-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: NSteven Rostedt <rostedt@goodmis.org> Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
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由 Paul E. McKenney 提交于
PREEMPT_RCU read-side critical sections blocking an expedited grace period invoke rcu_report_exp_rnp(). When the last such critical section has completed, rcu_report_exp_rnp() invokes the scheduler to wake up the task that invoked synchronize_rcu_expedited() -- needlessly holding the root rcu_node structure's lock while doing so, thus needlessly providing a way for RCU and the scheduler to deadlock. This commit therefore releases the root rcu_node structure's lock before calling wake_up(). Reported-by: NEd Tomlinson <edt@aei.ca> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
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