- 24 Jan, 2013 1 commit
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Steven Rostedt authored
Dan's smatch found a compare bug with the result of the trace_test_and_set_recursion() and comparing to less than zero. If the function fails, it returns -1, but was saved in an unsigned int, which will never be less than zero and will ignore the result of the test if a recursion did happen. Luckily this is the last of the recursion tests, as the infrastructure of ftrace would catch recursions before it got here, except for some few exceptions. Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org>
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- 23 Jan, 2013 11 commits
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Steven Rostedt authored
ring_buffer.c use to require declarations from trace.h, but these have moved to the generic header files. There's nothing in trace.h that ring_buffer.c requires. There's some headers that trace.h included that ring_buffer.c needs, but it's best that it includes them directly, and not include trace.h. Also, some things may use ring_buffer.c without having tracing configured. This removes the dependency that may come in the future. Signed-off-by: -
Steven Rostedt authored
Using context bit recursion checking, we can help increase the performance of the ring buffer. Before this patch: # echo function > /debug/tracing/current_tracer # for i in `seq 10`; do ./hackbench 50; done Time: 10.285 Time: 10.407 Time: 10.243 Time: 10.372 Time: 10.380 Time: 10.198 Time: 10.272 Time: 10.354 Time: 10.248 Time: 10.253 (average: 10.3012) Now we have: # echo function > /debug/tracing/current_tracer # for i in `seq 10`; do ./hackbench 50; done Time: 9.712 Time: 9.824 Time: 9.861 Time: 9.827 Time: 9.962 Time: 9.905 Time: 9.886 Time: 10.088 Time: 9.861 Time: 9.834 (average: 9.876) a 4% savings! Signed-off-by: -
Steven Rostedt authored
The function tracer had two different versions of function tracing. The disabling of irqs version and the preempt disable version. As function tracing in very intrusive and can cause nasty recursion issues, it has its own recursion protection. But the old method to do this was a flat layer. If it detected that a recursion was happening then it would just return without recording. This made the preempt version (much faster than the irq disabling one) not very useful, because if an interrupt were to occur after the recursion flag was set, the interrupt would not be traced at all, because every function that was traced would think it recursed on itself (due to the context it preempted setting the recursive flag). Now that we have a recursion flag for every context level, we no longer need to worry about that. We can disable preemption, set the current context recursion check bit, and go on. If an interrupt were to come along, it would check its own context bit and happily continue to trace. As the preempt version is faster than the irq disable version, there's no more reason to keep the preempt version around. And the irq disable version still had an issue with missing out on tracing NMI code. Remove the irq disable function tracer version and have the preempt disable version be the default (and only version). Before this patch we had from running: # echo function > /debug/tracing/current_tracer # for i in `seq 10`; do ./hackbench 50; done Time: 12.028 Time: 11.945 Time: 11.925 Time: 11.964 Time: 12.002 Time: 11.910 Time: 11.944 Time: 11.929 Time: 11.941 Time: 11.924 (average: 11.9512) Now we have: # echo function > /debug/tracing/current_tracer # for i in `seq 10`; do ./hackbench 50; done Time: 10.285 Time: 10.407 Time: 10.243 Time: 10.372 Time: 10.380 Time: 10.198 Time: 10.272 Time: 10.354 Time: 10.248 Time: 10.253 (average: 10.3012) a 13.8% savings! Signed-off-by: -
Steven Rostedt authored
When function tracing occurs, the following steps are made: If arch does not support a ftrace feature: call internal function (uses INTERNAL bits) which calls... If callback is registered to the "global" list, the list function is called and recursion checks the GLOBAL bits. then this function calls... The function callback, which can use the FTRACE bits to check for recursion. Now if the arch does not suppport a feature, and it calls the global list function which calls the ftrace callback all three of these steps will do a recursion protection. There's no reason to do one if the previous caller already did. The recursion that we are protecting against will go through the same steps again. To prevent the multiple recursion checks, if a recursion bit is set that is higher than the MAX bit of the current check, then we know that the check was made by the previous caller, and we can skip the current check. Signed-off-by: -
Steven Rostedt authored
Convert the bits into enums which makes the code a little easier to maintain. Signed-off-by: -
Steven Rostedt authored
Currently for recursion checking in the function tracer, ftrace tests a task_struct bit to determine if the function tracer had recursed or not. If it has, then it will will return without going further. But this leads to races. If an interrupt came in after the bit was set, the functions being traced would see that bit set and think that the function tracer recursed on itself, and would return. Instead add a bit for each context (normal, softirq, irq and nmi). A check of which context the task is in is made before testing the associated bit. Now if an interrupt preempts the function tracer after the previous context has been set, the interrupt functions can still be traced. Signed-off-by: -
Steven Rostedt authored
There is lots of places that perform: op = rcu_dereference_raw(ftrace_control_list); while (op != &ftrace_list_end) { Add a helper macro to do this, and also optimize for a single entity. That is, gcc will optimize a loop for either no iterations or more than one iteration. But usually only a single callback is registered to the function tracer, thus the optimized case should be a single pass. to do this we now do: op = rcu_dereference_raw(list); do { [...] } while (likely(op = rcu_dereference_raw((op)->next)) && unlikely((op) != &ftrace_list_end)); An op is always registered (ftrace_list_end when no callbacks is registered), thus when a single callback is registered, the link list looks like: top => callback => ftrace_list_end => NULL. The likely(op = op->next) still must be performed due to the race of removing the callback, where the first op assignment could equal ftrace_list_end. In that case, the op->next would be NULL. But this is unlikely (only happens in a race condition when removing the callback). But it is very likely that the next op would be ftrace_list_end, unless more than one callback has been registered. This tells gcc what the most common case is and makes the fast path with the least amount of branches. Signed-off-by: -
Steven Rostedt authored
The function tracing recursion self test should not crash the machine if the resursion test fails. If it detects that the function tracing is recursing when it should not be, then bail, don't go into an infinite recursive loop. Signed-off-by: -
Steven Rostedt authored
If one of the function tracers set by the global ops is not recursion safe, it can still be called directly without the added recursion supplied by the ftrace infrastructure. Signed-off-by: -
Steven Rostedt authored
The test that checks function recursion does things differently if the arch does not support all ftrace features. But that really doesn't make a difference with how the test runs, and either way the count variable should be 2 at the end. Currently the test wrongly fails for archs that don't support all the ftrace features. Signed-off-by: -
Steven Rostedt authored
There's a race condition between the setting of a new tracer and the update of the max trace buffers (the swap). When a new tracer is added, it sets current_trace to nop_trace before disabling the old tracer. At this moment, if the old tracer uses update_max_tr(), the update may trigger the warning against !current_trace->use_max-tr, as nop_trace doesn't have that set. As update_max_tr() requires that interrupts be disabled, we can add a check to see if current_trace == nop_trace and bail if it does. Then when disabling the current_trace, set it to nop_trace and run synchronize_sched(). This will make sure all calls to update_max_tr() have completed (it was called with interrupts disabled). As a clean up, this commit also removes shrinking and recreating the max_tr buffer if the old and new tracers both have use_max_tr set. The old way use to always shrink the buffer, and then expand it for the next tracer. This is a waste of time. Signed-off-by:
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- 22 Jan, 2013 2 commits
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Steven Rostedt authored
As trace_clock is used by other things besides tracing, and it does not require anything from trace.h, it is best not to include the header file in trace_clock.c. Signed-off-by: -
Steven Rostedt authored
Due to a userspace issue with PowerTop v2beta, which hardcoded the offset of event fields that it was using, it broke when we removed the Big Kernel Lock counter from the event header. (commit e6e1e259 "tracing: Remove lock_depth from event entry") Because this broke userspace, it was determined that we must keep those 4 bytes around. (commit a3a4a5ac "Regression: partial revert "tracing: Remove lock_depth from event entry"") This unfortunately wastes space in the ring buffer. 4 bytes per event, where a lot of events are just 24 bytes. That's 16% of the buffer wasted. A million events will add 4 megs of white space into the buffer. It was later noticed that PowerTop v2beta could not work on systems where the kernel was 64 bit but the userspace was 32 bits. The reason was because the offsets are different between the two and the hard coded offset of one would not work with the other. With PowerTop v2 final, it implemented the same interface that both perf and trace-cmd use. That is, it reads the format file of the event to find the offsets of the fields it needs. This fixes the problem with running powertop on a 32 bit userspace running on a 64 bit kernel. It also no longer requires the 4 byte padding. As PowerTop v2 has been out for a while, and is included in all major distributions, it is time that we can safely remove the 4 bytes of padding. Users of PowerTop v2beta should upgrade to PowerTop v2 final. Cc: Linus Torvalds <torvalds@linux-foundation.org> Acked-by:
Arjan van de Ven <arjan@linux.intel.com> Signed-off-by:
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- 21 Jan, 2013 13 commits
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Masami Hiramatsu authored
Move arch-dep kprobes stuff under arch/x86/kernel/kprobes. Link: http://lkml.kernel.org/r/20120928081522.3560.75469.stgit@ltc138.sdl.hitachi.co.jp Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [ fixed whitespace and s/__attribute__((packed))/__packed/ ] Signed-off-by:
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Masami Hiramatsu authored
Split ftrace-based kprobes code from kprobes, and introduce CONFIG_(HAVE_)KPROBES_ON_FTRACE Kconfig flags. For the cleanup reason, this also moves kprobe_ftrace check into skip_singlestep. Link: http://lkml.kernel.org/r/20120928081520.3560.25624.stgit@ltc138.sdl.hitachi.co.jp Cc: Ingo Molnar <mingo@elte.hu> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
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Masami Hiramatsu authored
Move SAVE_REGS support flag into Kconfig and rename it to CONFIG_DYNAMIC_FTRACE_WITH_REGS. This also introduces CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which indicates the architecture depending part of ftrace has a code that saves full registers. On the other hand, CONFIG_DYNAMIC_FTRACE_WITH_REGS indicates the code is enabled. Link: http://lkml.kernel.org/r/20120928081516.3560.72534.stgit@ltc138.sdl.hitachi.co.jp Cc: Ingo Molnar <mingo@elte.hu> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:
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Steven Rostedt authored
Add the file max_graph_depth to the debug tracing directory that lets the user define the depth of the function graph. A very useful operation is to set the depth to 1. Then it traces only the first function that is called when entering the kernel. This can be used to determine what system operations interrupt a process. For example, to work on NOHZ processes (single tasks running without a timer tick), if any interrupt goes off and preempts that task, this code will show it happening. # cd /sys/kernel/debug/tracing # echo 1 > max_graph_depth # echo function_graph > current_tracer # cat per_cpu/cpu/<cpu-of-process>/trace Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: -
Steven Rostedt authored
When function tracing with either debug locks enabled or tracing preempt disabled, the add_preempt_count() is traced. This is an issue with lockdep and function tracing. As function tracing can disable interrupts, and lockdep records that change, lockdep may not be able to handle this recursion if it happens from an NMI context. The first thing that an NMI does is: #define nmi_enter() \ do { \ ftrace_nmi_enter(); \ BUG_ON(in_nmi()); \ add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ lockdep_off(); \ rcu_nmi_enter(); \ trace_hardirq_enter(); \ } while (0) When the add_preempt_count() is traced, and the tracing callback disables interrupts, it will jump into the lockdep code. There's some places in lockdep that can't handle this re-entrance, and causes lockdep to fail. As the lockdep_off() (and lockdep_on) is a simple: void lockdep_off(void) { current->lockdep_recursion++; } and is never traced, it can be called first in nmi_enter() and lockdep_on() last in nmi_exit(). Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: -
Steven Rostedt authored
There's now a check in tracing_reset_online_cpus() if the buffer is allocated or NULL. No need to do a check before calling it with max_tr. Signed-off-by: -
Hiraku Toyooka authored
max_tr->buffer could be NULL in the tracing_reset{_online_cpus}. In this case, a NULL pointer dereference happens, so we should return immediately from these functions. Note, the current code does not call tracing_reset*() with max_tr when its buffer is NULL, but future code will. This patch is needed to prevent the future code from crashing. Link: http://lkml.kernel.org/r/20121219070234.31200.93863.stgit@liselsiaSigned-off-by:Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by:
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Fengguang Wu authored
Some functions in the syscall tracing is used only locally to the file, but they are labeled global. Convert them to static functions. Signed-off-by:
Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
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Jovi Zhang authored
Without this patch, we can register a uprobe event for a directory. Enabling such a uprobe event would anyway fail. Example: $ echo 'p /bin:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events However dirctories cannot be valid targets for uprobe. Hence verify if the target is a regular file during the probe registration. Link: http://lkml.kernel.org/r/20130103004212.690763002@goodmis.org Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by:
Jovi Zhang <bookjovi@gmail.com> Acked-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> [ cleaned up whitespace and removed redundant IS_DIR() check ] Signed-off-by:
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Shan Wei authored
typeof(&buffer) is a pointer to array of 1024 char, or char (*)[1024]. But, typeof(&buffer[0]) is a pointer to char which match the return type of get_trace_buf(). As well-known, the value of &buffer is equal to &buffer[0]. so return this_cpu_ptr(&percpu_buffer->buffer[0]) can avoid type cast. Link: http://lkml.kernel.org/r/50A1A800.3020102@gmail.comReviewed-by:
Christoph Lameter <cl@linux.com> Signed-off-by:
Shan Wei <davidshan@tencent.com> Signed-off-by:
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Steven Rostedt authored
The original ring-buffer code had special checks at the start of rb_advance_iter() and instead of repeating them again at the end of the function if a certain condition existed, I just did a recursive call to rb_advance_iter() because the special condition would cause rb_advance_iter() to return early (after the checks). But as things have changed, the special checks no longer exist and the only thing done for the special_condition is to call rb_inc_iter() and return. Instead of doing a confusing recursive call, just call rb_inc_iter instead. Signed-off-by: -
Steven Rostedt authored
Sparse complains when is_signed_type() is used on a pointer. This macro is needed for the format output used for ftrace and perf, to know if a binary field is a signed type or not. The is_signed_type() macro is used against all fields that are recorded by events to automate the operation. The problem sparse has is with the current way is_signed_type() works: ((type)-1 < 0) If "type" is a poiner, than sparse does not like it being compared to an integer (zero). The simple fix is to just give zero the same type. The runtime result stays the same. Reported-by:
Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by:
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Steven Rostedt authored
If some other kernel subsystem has a module notifier, and adds a kprobe to a ftrace mcount point (now that kprobes work on ftrace points), when the ftrace notifier runs it will fail and disable ftrace, as well as kprobes that are attached to ftrace points. Here's the error: WARNING: at kernel/trace/ftrace.c:1618 ftrace_bug+0x239/0x280() Hardware name: Bochs Modules linked in: fat(+) stap_56d28a51b3fe546293ca0700b10bcb29__8059(F) nfsv4 auth_rpcgss nfs dns_resolver fscache xt_nat iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack lockd sunrpc ppdev parport_pc parport microcode virtio_net i2c_piix4 drm_kms_helper ttm drm i2c_core [last unloaded: bid_shared] Pid: 8068, comm: modprobe Tainted: GF 3.7.0-0.rc8.git0.1.fc19.x86_64 #1 Call Trace: [<ffffffff8105e70f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff81134106>] ? __probe_kernel_read+0x46/0x70 [<ffffffffa0180000>] ? 0xffffffffa017ffff [<ffffffffa0180000>] ? 0xffffffffa017ffff [<ffffffff8105e76a>] warn_slowpath_null+0x1a/0x20 [<ffffffff810fd189>] ftrace_bug+0x239/0x280 [<ffffffff810fd626>] ftrace_process_locs+0x376/0x520 [<ffffffff810fefb7>] ftrace_module_notify+0x47/0x50 [<ffffffff8163912d>] notifier_call_chain+0x4d/0x70 [<ffffffff810882f8>] __blocking_notifier_call_chain+0x58/0x80 [<ffffffff81088336>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff810c2a23>] sys_init_module+0x73/0x220 [<ffffffff8163d719>] system_call_fastpath+0x16/0x1b ---[ end trace 9ef46351e53bbf80 ]--- ftrace failed to modify [<ffffffffa0180000>] init_once+0x0/0x20 [fat] actual: cc:bb:d2:4b:e1 A kprobe was added to the init_once() function in the fat module on load. But this happened before ftrace could have touched the code. As ftrace didn't run yet, the kprobe system had no idea it was a ftrace point and simply added a breakpoint to the code (0xcc in the cc:bb:d2:4b:e1). Then when ftrace went to modify the location from a call to mcount/fentry into a nop, it didn't see a call op, but instead it saw the breakpoint op and not knowing what to do with it, ftrace shut itself down. The solution is to simply give the ftrace module notifier the max priority. This should have been done regardless, as the core code ftrace modification also happens very early on in boot up. This makes the module modification closer to core modification. Link: http://lkml.kernel.org/r/20130107140333.593683061@goodmis.org Cc: stable@vger.kernel.org Acked-by:
Frank Ch. Eigler <fche@redhat.com> Signed-off-by:
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- 18 Jan, 2013 1 commit
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Linus Torvalds authored
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- 17 Jan, 2013 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linuxLinus Torvalds authored
Pull more s390 patches from Martin Schwidefsky: "A couple of bug fixes: one of the transparent huge page primitives is broken, the sched_clock function overflows after 417 days, the XFS module has grown too large for -fpic and the new pci code has broken normal channel subsystem notifications." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/chsc: fix SEI usage s390/time: fix sched_clock() overflow s390: use -fPIC for module compile s390/mm: fix pmd_pfn() for thp
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git://oss.sgi.com/xfs/xfsLinus Torvalds authored
Pull xfs bugfixes from Ben Myers: - fix(es) for compound buffers - fix for dquot soft timer asserts due to overflow of d_blk_softlimit - fix for regression in dir v2 code introduced in commit 20f7e9f3 ("xfs: factor dir2 block read operations") * tag 'for-linus-v3.8-rc4' of git://oss.sgi.com/xfs/xfs: xfs: recalculate leaf entry pointer after compacting a dir2 block xfs: remove int casts from debug dquot soft limit timer asserts xfs: fix the multi-segment log buffer format xfs: fix segment in xfs_buf_item_format_segment xfs: rename bli_format to avoid confusion with bli_formats xfs: use b_maps[] for discontiguous buffers
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- 16 Jan, 2013 10 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
Pull ACPI and power management fixes from Rafael Wysocki: - cpuidle regression fix related to the initialization of state kobjects from Krzysztof Mazur. - cpuidle fix removing some not very useful code and making some user-visible problems go away at the same time. From Daniel Lezcano. - ACPI build fix from Yinghai Lu. * tag 'pm+acpi-for-3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: remove the power_specified field in the driver ACPI / glue: Fix build with ACPI_GLUE_DEBUG set cpuidle: fix number of initialized/destroyed states
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Eric Sandeen authored
Dave Jones hit this assert when doing a compile on recent git, with CONFIG_XFS_DEBUG enabled: XFS: Assertion failed: (char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)), file: fs/xfs/xfs_dir2_data.c, line: 828 Upon further digging, the tag found by xfs_dir2_data_unused_tag_p(dup) contained "2" and not the proper offset, and I found that this value was changed after the memmoves under "Use a stale leaf for our new entry." in xfs_dir2_block_addname(), i.e. memmove(&blp[mid + 1], &blp[mid], (highstale - mid) * sizeof(*blp)); overwrote it. What has happened is that the previous call to xfs_dir2_block_compact() has rearranged things; it changes btp->count as well as the blp array. So after we make that call, we must recalculate the proper pointer to the leaf entries by making another call to xfs_dir2_block_leaf_p(). Dave provided a metadump image which led to a simple reproducer (create a particular filename in the affected directory) and this resolves the testcase as well as the bug on his live system. Thanks also to dchinner for looking at this one with me. Signed-off-by:Eric Sandeen <sandeen@redhat.com> Tested-by:
Dave Jones <davej@redhat.com> Reviewed-by:
Dave Chinner <dchinner@redhat.com> Reviewed-by:
Mark Tinguely <tinguely@sgi.com> Signed-off-by:
Ben Myers <bpm@sgi.com>
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Brian Foster authored
The int casts here make it easy to trigger an assert with a large soft limit. For example, set a >4TB soft limit on an empty volume to reproduce a (0 > -x) comparison due to an overflow of d_blk_softlimit. Signed-off-by:
Brian Foster <bfoster@redhat.com> Reviewed-by:
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Mark Tinguely authored
Per Dave Chinner suggestion, this patch: 1) Corrects the detection of whether a multi-segment buffer is still tracking data. 2) Clears all the buffer log formats for a multi-segment buffer. Signed-off-by:Christoph Hellwig <hch@lst.de> Reviewed-by:
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Mark Tinguely authored
Not every segment in a multi-segment buffer is dirty in a transaction and they will not be outputted. The assert in xfs_buf_item_format_segment() that checks for the at least one chunk of data in the segment to be used is not necessary true for multi-segmented buffers. Signed-off-by:
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Mark Tinguely authored
Rename the bli_format structure to __bli_format to avoid accidently confusing them with the bli_formats pointer. Signed-off-by:
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Mark Tinguely authored
Commits starting at 77c1a08f introduced a multiple segment support to xfs_buf. xfs_trans_buf_item_match() could not find a multi-segment buffer in the transaction because it was looking at the single segment block number rather than the multi-segment b_maps[0].bm.bn. This results on a recursive buffer lock that can never be satisfied. This patch: 1) Changed the remaining b_map accesses to be b_maps[0] accesses. 2) Renames the single segment b_map structure to __b_map to avoid future confusion. Signed-off-by:
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Kirill Smelkov authored
In commit 281dc5c5 ("Give up on pushing CC_OPTIMIZE_FOR_SIZE") we already changed the actual default value, but the help-text still suggested 'y'. Fix the help text too, for all the same reasons. Sadly, -Os keeps on generating some very suboptimal code for certain cases, to the point where any I$ miss upside is swamped by the downside. The main ones are: - using "rep movsb" for memcpy, even on CPU's where that is horrendously bad for performance. - not honoring branch prediction information, so any I$ footprint you win from smaller code, you lose from less code density in the I$. - using divide instructions when that is very expensive. Signed-off-by:
Kirill Smelkov <kirr@mns.spb.ru> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Chuansheng Liu authored
Fix the build error: drivers/built-in.o: In function `twl_probe': drivers/mfd/twl-core.c:1256: undefined reference to `devm_regmap_init_i2c' make: *** [vmlinux] Error 1 Signed-off-by:
liu chuansheng <chuansheng.liu@intel.com> Acked-by:
Peter Ujfalusi <peter.ujfalusi@ti.com> [ Samuel is busy, taking it directly - Linus ] Signed-off-by:
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Ralf Baechle authored
[ We should make fun of people who can't speel too, but then we'd have no time for any real work at all - Linus ] Signed-off-by:
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