- 06 Jun, 2012 25 commits
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Vince Weaver authored
The rdpmc instruction is faster than the equivelant rdmsr call, so use it when possible in the kernel. The perfctr kernel patches did this, after extensive testing showed rdpmc to always be faster (One can look in etc/costs in the perfctr-2.6 package to see a historical list of the overhead). I have done some tests on a 3.2 kernel, the kernel module I used was included in the first posting of this patch: rdmsr rdpmc Core2 T9900: 203.9 cycles 30.9 cycles AMD fam0fh: 56.2 cycles 9.8 cycles Atom 6/28/2: 129.7 cycles 50.6 cycles The speedup of using rdpmc is large. [ It's probably possible (and desirable) to do this without requiring a new field in the hw_perf_event structure, but the fixed events make this tricky. ] Signed-off-by:Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1203011724030.26934@cl320.eecs.utk.eduSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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Andi Kleen authored
Add a version of rdpmc() that directly reads into a u64 Signed-off-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
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Peter Zijlstra authored
Move the wrmslr() debug wrapper to the common header now that all the include games are gone. Also clean it up a bit to avoid multiple evaluation of the argument. Signed-off-by:
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Ingo Molnar authored
Eliminate a conflict in a patch I am going to apply. Signed-off-by: -
Peter Zijlstra authored
Afaict there's no need to (incompletely) iterate the MEM_UOPS_RETIRED.* umask state. Signed-off-by:
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Peter Zijlstra authored
Implement rudimentary IVB perf support. The SDM states its identical to SNB with exception of the exact event tables, but a quick look suggests they're similar enough. Also mark SNB-EP as broken for now. Requested-and-tested-by:
Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Signed-off-by:
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Peter Zijlstra authored
Now that there's finally a chip with working PEBS (IvyBridge), we can enable the hardware and implement cycles:p for SNB/IVB. Cc: Stephane Eranian <eranian@google.com> Requested-and-tested-by:
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Peter Zijlstra authored
Zheng Yan reported that event group validation can wreck event state when Intel extra_reg allocation changes event state. Validation shouldn't change any persistent state. Cloning events in validate_{event,group}() isn't really pretty either, so add a few special cases to avoid modifying the event state. The code is restructured to minimize the special case impact. Reported-by:Zheng Yan <zheng.z.yan@linux.intel.com> Acked-by:
Stephane Eranian <eranian@google.com> Signed-off-by:
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Oleg Nesterov authored
Kill the no longer needed uprobes_srcu/uprobe_srcu_id code. It doesn't really work anyway. synchronize_srcu() can only synchronize with the code "inside" the srcu_read_lock/srcu_read_unlock section, while uprobe_pre_sstep_notifier() does srcu_read_lock() _after_ we already hit the breakpoint. I guess this probably works "in practice". synchronize_srcu() is slow and it implies synchronize_sched(), and the probed task enters the non- preemptible section at the start of exception handler. Still this is not right at least in theory, and task->uprobe_srcu_id blows task_struct. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120529193008.GG8057@redhat.comSigned-off-by:
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Oleg Nesterov authored
Currently handle_swbp() assumes that it can't race with unregister, so it roughly does: if (find_uprobe(vaddr)) process_uprobe(); else send_sig(SIGTRAP); This relies on the not-really-working uprobes_srcu code we are going to remove, see the next patch. With this patch we rely on the result of is_swbp_at_addr(bp_vaddr) if find_uprobe() fails. If is_swbp == 1, then we hit the normal int3, we should send SIGTRAP. If is_swbp == 0, we raced with uprobe_unregister(), we simply restart this insn again. The "difficult" case is is_swbp == -EFAULT, when we can't read this memory. In this case I think we should restart too, and this is more correct compared to the current code which sends SIGTRAP. Ignoring ENOMEM/etc from get_user_pages(), this can only happen if another thread unmaps this memory before find_active_uprobe() takes mmap_sem. It would be better to pretend it was unmapped before this insn was executed, restart, and get SIGSEGV. Signed-off-by:
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Oleg Nesterov authored
Change register_for_each_vma() to take mm->mmap_sem for writing. This is a bit unfortunate but hopefully not too bad, this is the slow path anyway. This is needed to ensure that find_active_uprobe() can not race with uprobe_register() which adds the new bp at the same bp_vaddr, after find_uprobe() fails and before is_swbp_at_addr_fast() checks the memory. IOW, this is needed to ensure that if find_active_uprobe() returns NULL but is_swbp == true, we can safely assume that it was the "normal" int3 and we should send SIGTRAP. There is another reason for this change. We are going to replace uprobes_state->count with MMF_ flags set by register/unregister and cleared by find_active_uprobe(), and set/clear shouldn't race with each other. Signed-off-by:
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Oleg Nesterov authored
A separate patch to simplify the review, and for the documentation. The patch adds another "int *is_swbp" argument to find_active_uprobe(), so far its only caller doesn't use this info. With this patch find_active_uprobe() additionally does: - if find_vma() + ->vm_start check fails, *is_swbp = -EFAULT - otherwise, if valid_vma() + find_uprobe() fails, it holds the result of is_swbp_at_addr(), can be negative too. The latter is only possible if we raced with another thread which did munmap/etc after we hit this bp. IOW. If find_active_uprobe(&is_swbp) returns NULL, the caller can look at is_swbp to figure out whether the current insn is bp or not, or detect the race with another thread if it is negative. Note: I think that performance-wise this change is fine. This adds is_swbp_at_addr(), but only if we raced with uprobe_unregister() or if we hit the "normal" int3 but this mm has uprobes as well. And even in this case the slow read_opcode() path is very unlikely, this insn recently triggered do_int3(), __copy_from_user_inatomic() shouldn't fail in the likely case. Signed-off-by:
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Oleg Nesterov authored
No functional changes. Move the "find uprobe" code from handle_swbp() to the new helper, find_active_uprobe(). Note: with or without this change, the find-active-uprobe logic is not exactly right. We can race with another thread which unmaps the memory with the valid uprobe before we take mm->mmap_sem. We can't find this uprobe simply because find_vma() fails. In this case we wrongly assume that this trap was not caused by uprobe and send the erroneous SIGTRAP. See the next changes. Signed-off-by:
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Oleg Nesterov authored
set_orig_insn()->read_opcode() should not fail if the probed task did mprotect() after uprobe_register(), change it to use FOLL_FORCE. Without FOLL_WRITE this doesn't have any "side" effect but allows to read the !VM_READ memory. There is another reason for this change, we are going to use is_swbp_at_addr() from handle_swbp() which can race with another thread doing mprotect(). Signed-off-by:
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Oleg Nesterov authored
Change is_swbp_at_addr() to try to avoid the costly read_opcode() if mm == current->mm, __copy_from_user_inatomic() should succeed in the likely case. Currently this optimization is not important, but we are going to add more is_swbp_at_addr(current->mm) callers. Signed-off-by:
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Arun Sharma authored
Signed-off-by:
Arun Sharma <asharma@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by:
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Arun Sharma authored
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Arun Sharma authored
Stack depth of 255 seems excessive, given that copy_from_user_nmi() could be slow. Signed-off-by:
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Arun Sharma authored
Without this patch, applications with two different stack regions (eg: native stack vs JIT stack) get truncated callchains even when RBP chaining is present. GDB shows proper stack traces and the frame pointer chaining is intact. This patch disables the (fp < RSP) check, hoping that other checks in the code save the day for us. In our limited testing, this didn't seem to break anything. In the long term, we could potentially have userspace advise the kernel on the range of valid stack addresses, so we don't spend a lot of time unwinding from bogus addresses. Signed-off-by:
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Peter Zijlstra authored
Afaict there's no need to (incompletely) iterate the MEM_UOPS_RETIRED.* umask state. Signed-off-by:
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Peter Zijlstra authored
Implement rudimentary IVB perf support. The SDM states its identical to SNB with exception of the exact event tables, but a quick look suggests they're similar enough. Also mark SNB-EP as broken for now. Requested-and-tested-by:
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Peter Zijlstra authored
Now that there's finally a chip with working PEBS (IvyBridge), we can enable the hardware and implement cycles:p for SNB/IVB. Cc: Stephane Eranian <eranian@google.com> Requested-and-tested-by:
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Peter Zijlstra authored
Zheng Yan reported that event group validation can wreck event state when Intel extra_reg allocation changes event state. Validation shouldn't change any persistent state. Cloning events in validate_{event,group}() isn't really pretty either, so add a few special cases to avoid modifying the event state. The code is restructured to minimize the special case impact. Reported-by: -
Masami Hiramatsu authored
Fix the x86 instruction decoder to decode bsr/bsf/jmpe with operand-size prefix (66h). This fixes the test case failure reported by Linus, attached below. bsf/bsr/jmpe have a special encoding. Opcode map in Intel Software Developers Manual vol2 says they have TZCNT/LZCNT variants if it has F3h prefix. However, there is no information if it has other 66h or F2h prefixes. Current instruction decoder supposes that those are bad instructions, but it actually accepts at least operand-size prefixes. H. Peter Anvin further explains: " TZCNT/LZCNT are F3 + BSF/BSR exactly because the F2 and F3 prefixes have historically been no-ops with most instructions. This allows software to unconditionally use the prefixed versions and get TZCNT/LZCNT on the processors that have them if they don't care about the difference. " This fixes errors reported by test_get_len: Warning: arch/x86/tools/test_get_len found difference at <em_bsf>:ffffffff81036d87 Warning: ffffffff81036de5: 66 0f bc c2 bsf %dx,%ax Warning: objdump says 4 bytes, but insn_get_length() says 3 Warning: arch/x86/tools/test_get_len found difference at <em_bsr>:ffffffff81036ea6 Warning: ffffffff81036f04: 66 0f bd c2 bsr %dx,%ax Warning: objdump says 4 bytes, but insn_get_length() says 3 Warning: decoded and checked 13298882 instructions with 2 warnings Reported-by:
Pekka Enberg <penberg@kernel.org> Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <yrl.pp-manager.tt@hitachi.com> Link: http://lkml.kernel.org/r/20120604150911.22338.43296.stgit@localhost.localdomainSigned-off-by:
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Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf fixes from Arnaldo Carvalho de Melo: * Endianness fixes from Jiri Olsa * Fixes for make perf tarball * Fix for DSO name in perf script callchains, from David Ahern * Segfault fixes for perf top --callchain, from Namhyung Kim * Minor function result fixes from Srikar Dronamraju * Add missing 3rd ioctl parameter, from Namhyung Kim * Fix pager usage in minimal embedded systems, from Avik Sil Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
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- 05 Jun, 2012 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuseLinus Torvalds authored
Pull fuse updates from Miklos Szeredi. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: fix blksize calculation fuse: fix stat call on 32 bit platforms fuse: optimize fallocate on permanent failure fuse: add FALLOCATE operation fuse: Convert to kstrtoul_from_user
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler fixes from Ingo Molnar. * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Remove NULL assignment of dattr_cur sched: Remove the last NULL entry from sched_feat_names sched: Make sched_feat_names const sched/rt: Fix SCHED_RR across cgroups sched: Move nr_cpus_allowed out of 'struct sched_rt_entity' sched: Make sure to not re-read variables after validation sched: Fix SD_OVERLAP sched: Don't try allocating memory from offline nodes sched/nohz: Fix rq->cpu_load calculations some more sched/x86: Use cpu_llc_shared_mask(cpu) for coregroup_mask
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- 04 Jun, 2012 12 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/{signal,vfs}Linus Torvalds authored
Pull signal and vfs compile breakage fixes from Al Viro. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: fixups for signal breakage * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: nommu: fix compilation of nommu.c
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull cifs fixes from Steve French. * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: CIFS: Move get_next_mid to ops struct CIFS: Make accessing is_valid_oplock/dump_detail ops struct field safe CIFS: Improve identation in cifs_unlock_range CIFS: Fix possible wrong memory allocation
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Al Viro authored
Obvious brainos spotted by Geert. Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
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Greg Ungerer authored
Compiling 3.5-rc1 for nommu targets gives: CC mm/nommu.o mm/nommu.c: In function ‘sys_mmap_pgoff’: mm/nommu.c:1489:2: error: ‘ret’ undeclared (first use in this function) mm/nommu.c:1489:2: note: each undeclared identifier is reported only once for each function it appears in It is trivially fixed by replacing 'ret' with the local variable that is already defined for the return value 'retval'. Signed-off-by:
Greg Ungerer <gerg@uclinux.org> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mmLinus Torvalds authored
Pull frontswap feature from Konrad Rzeszutek Wilk: "Frontswap provides a "transcendent memory" interface for swap pages. In some environments, dramatic performance savings may be obtained because swapped pages are saved in RAM (or a RAM-like device) instead of a swap disk. This tag provides the basic infrastructure along with some changes to the existing backends." Fix up trivial conflict in mm/Makefile due to removal of swap token code changing a line next to the new frontswap entry. This pull request came in before the merge window even opened, it got delayed to after the merge window by me just wanting to make sure it had actual users. Apparently IBM is using this on their embedded side, and Jan Beulich says that it's already made available for SLES and OpenSUSE users. Also acked by Rik van Riel, and Konrad points to other people liking it too. So in it goes. By Dan Magenheimer (4) and Konrad Rzeszutek Wilk (2) via Konrad Rzeszutek Wilk * tag 'stable/frontswap.v16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm: frontswap: s/put_page/store/g s/get_page/load MAINTAINER: Add myself for the frontswap API mm: frontswap: config and doc files mm: frontswap: core frontswap functionality mm: frontswap: core swap subsystem hooks and headers mm: frontswap: add frontswap header file
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Linus Torvalds authored
Merge branches 'irq-urgent-for-linus' and 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq and smpboot updates from Thomas Gleixner: "Just cleanup patches with no functional change and a fix for suspend issues." * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Introduce irq_do_set_affinity() to reduce duplicated code genirq: Add IRQS_PENDING for nested and simple irq * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smpboot, idle: Fix comment mismatch over idle_threads_init() smpboot, idle: Optimize calls to smp_processor_id() in idle_threads_init()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer updates from Thomas Gleixner: "The clocksource driver is pure hardware enablement and the skew option is default off, well tested and non dangerous." * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick: Move skew_tick option into the HIGH_RES_TIMER section clocksource: em_sti: Add DT support clocksource: em_sti: Emma Mobile STI driver clockevents: Make clockevents_config() a global symbol tick: Add tick skew boot option
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Linus Torvalds authored
Cyrill Gorcunov reports that I broke the fdinfo files with commit 30a08bf2 ("proc: move fd symlink i_mode calculations into tid_fd_revalidate()"), and he's quite right. The tid_fd_revalidate() function is not just used for the <tid>/fd symlinks, it's also used for the <tid>/fdinfo/<fd> files, and the permission model for those are different. So do the dynamic symlink permission handling just for symlinks, making the fdinfo files once more appear as the proper regular files they are. Of course, Al Viro argued (probably correctly) that we shouldn't do the symlink permission games at all, and make the symlinks always just be the normal 'lrwxrwxrwx'. That would have avoided this issue too, but since somebody noticed that the permissions had changed (which was the reason for that original commit 30a08bf2 in the first place), people do apparently use this feature. [ Basically, you can use the symlink permission data as a cheap "fdinfo" replacement, since you see whether the file is open for reading and/or writing by just looking at st_mode of the symlink. So the feature does make sense, even if the pain it has caused means we probably shouldn't have done it to begin with. ] Reported-and-tested-by:
Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by:
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Kukjin Kim authored
Should be 'exynos5_xxx' instead of 'exonys5_xxx'. It happened at the commit 30b84288 ("Merge tag 'soc2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc") during v3.5 merge window. Signed-off-by:
Kukjin Kim <kgene.kim@samsung.com> [ My bad - Linus ] Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
Pull some left-over PM patches from Rafael J. Wysocki. * 'pm-acpi' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / PM: Make acpi_pm_device_sleep_state() follow the specification ACPI / PM: Make __acpi_bus_get_power() cover D3cold correctly ACPI / PM: Fix error messages in drivers/acpi/bus.c rtc-cmos / PM: report wakeup event on ACPI RTC alarm ACPI / PM: Generate wakeup events on fixed power button
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Linus Torvalds authored
This reverts commit 5ceb9ce6. That commit seems to be the cause of the mm compation list corruption issues that Dave Jones reported. The locking (or rather, absense there-of) is dubious, as is the use of the 'page' variable once it has been found to be outside the pageblock range. So revert it for now, we can re-visit this for 3.6. If we even need to: as Minchan Kim says, "The patch wasn't a bug fix and even test workload was very theoretical". Reported-and-tested-by:
Dave Jones <davej@redhat.com> Acked-by:
Hugh Dickins <hughd@google.com> Acked-by:
KOSAKI Motohiro <kosaki.motohiro@gmail.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Hugh Dickins authored
New tmpfs use of !PageUptodate pages for fallocate() is triggering the WARNING: at mm/page-writeback.c:1990 when __set_page_dirty_nobuffers() is called from migrate_page_copy() for compaction. It is anomalous that migration should use __set_page_dirty_nobuffers() on an address_space that does not participate in dirty and writeback accounting; and this has also been observed to insert surprising dirty tags into a tmpfs radix_tree, despite tmpfs not using tags at all. We should probably give migrate_page_copy() a better way to preserve the tag and migrate accounting info, when mapping_cap_account_dirty(). But that needs some more work: so in the interim, avoid the warning by using a simple SetPageDirty on PageSwapBacked pages. Reported-and-tested-by:
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- 03 Jun, 2012 1 commit
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Linus Torvalds authored
The comment above it says "Stat data, not accessed from path walking", but in fact some of inode fields we use for the common stat data was way down at the end of the inode, causing unnecessary cache misses for the common stat operations. The inode structure is pretty big, and this can change padding depending on field width, but at least on the common 64-bit configurations this doesn't change the size. Some of our inode layout has historically been to tro to avoid unnecessary padding fields, but cache locality is at least as important for layout, if not more. Noticed by looking at kernel profiles, and noticing that the "i_blkbits" access stood out like a sore thumb. Signed-off-by:
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