- 15 Sep, 2015 4 commits
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Viresh Kumar authored
OPP code is expanding and is already present in multiple directories (cpufreq and power). Lets move it to its own directory, to manage it better. This also moves/renames the cpufreq_opp file to cpu.c, as it will contain helpers for cpu device. Its not just about cpufreq, other frameworks can use OPPs as well. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Viresh Kumar authored
That's the naming convention followed in most of opp core, but few routines didn't follow this, fix them. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Viresh Kumar authored
free-table routines are opposite of init-table ones, and must be named to make that clear. Opposite of 'init' is 'exit', but those doesn't suit really well. Replace 'init' with 'add' and 'free' with 'remove'. Reported-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Viresh Kumar authored
We already have a better API to get the opp descriptor block's node from cpu-node. Lets reuse that instead of creating our own routines for the same stuff. That cleans the code a lot. This also kills a check we had earlier (as we are using the generic API now). Earlier we used to check if the operating-points-v2 property contained multiple phandles instead of a single phandle. Killing this check isn't an issue because, we only parse the first entry with of_parse_phandle(). So, if a user passes multiple phandles, its really his problem :) Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 12 Sep, 2015 13 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/jesper/crisLinus Torvalds authored
Pull CRIS updates from Jesper Nilsson: "Mostly removal of old cruft of which we can use a generic version, or fixes for code not commonly run in the cris port, but also additions to enable some good debug" * tag 'cris-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris: (25 commits) CRISv10: delete unused lib/dmacopy.c CRISv10: delete unused lib/old_checksum.c CRIS: fix switch_mm() lockdep splat CRISv32: enable LOCKDEP_SUPPORT CRIS: add STACKTRACE_SUPPORT CRISv32: annotate irq enable in idle loop CRISv32: add support for irqflags tracing CRIS: UAPI: use generic types.h CRIS: UAPI: use generic shmbuf.h CRIS: UAPI: use generic msgbuf.h CRIS: UAPI: use generic socket.h CRIS: UAPI: use generic sembuf.h CRIS: UAPI: use generic sockios.h CRIS: UAPI: use generic auxvec.h CRIS: UAPI: use generic headers via Kbuild CRIS: UAPI: fix elf.h export CRIS: don't make asm/elf.h depend on asm/user.h CRIS: UAPI: fix ptrace.h CRISv32: Squash compile warnings for axisflashmap CRISv32: Add GPIO driver to the default configs ...
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Linus Torvalds authored
rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not a boolean value. Now, admittedly the "!= 0" doesn't really change the value (0 stays as zero, 1 stays as one), but it's not only redundant, it confuses gcc, and causes gcc to warn about the construct switch (rq_data_dir(req)) { case READ: ... case WRITE: ... that we have in a few drivers. Now, the gcc warning is silly and stupid (it seems to warn not about the switch value having a different type from the case statements, but about _any_ boolean switch value), but in this case the code itself is silly and stupid too, so let's just change it, and get rid of warnings like this: drivers/block/hd.c: In function ‘hd_request’: drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool] switch (rq_data_dir(req)) { The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in commit 5953316d ("block: make rq->cmd_flags be 64-bit") and is presumably because the old code (that just did a logical 'and' with 1) would then end up making the type of rq_data_dir() be u64 too. But if we want to retain the old regular integer type, let's just cast the result to 'int' rather than use that rather odd '!= 0'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
Fix up the writeback plugging introduced in commit d353d758 ("writeback: plug writeback at a high level") that then caused problems due to the unplug happening with a spinlock held. * writeback-plugging: writeback: plug writeback in wb_writeback() and writeback_inodes_wb() Revert "writeback: plug writeback at a high level"
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Linus Torvalds authored
We had to revert the pluggin in writeback_sb_inodes() because the wb->list_lock is held, but we could easily plug at a higher level before taking that lock, and unplug after releasing it. This does that. Chris will run performance numbers, just to verify that this approach is comparable to the alternative (we could just drop and re-take the lock around the blk_finish_plug() rather than these two commits. I'd have preferred waiting for actual performance numbers before picking one approach over the other, but I don't want to release rc1 with the known "sleeping function called from invalid context" issue, so I'll pick this cleanup version for now. But if the numbers show that we really want to plug just at the writeback_sb_inodes() level, and we should just play ugly games with the spinlock, we'll switch to that. Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
I didn't notice this when merging the thermal code from Zhang, but his merge (commit 5a924a07: "Merge branches 'thermal-core' and 'thermal-intel' of .git into next") of the thermal-core and thermal-intel branches was wrong. In thermal-core, commit 17e8351a ("thermal: consistently use int for temperatures") converted the thermal layer to use "int" for temperatures. But in parallel, in the thermal-intel branch commit d0a12625 ("thermal: Add Intel PCH thermal driver") added support for the intel PCH thermal sensor using the old interfaces that used "unsigned long" pointers. This resulted in warnings like this: drivers/thermal/intel_pch_thermal.c:184:14: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types] .get_temp = pch_thermal_get_temp, ^ drivers/thermal/intel_pch_thermal.c:184:14: note: (near initialization for ‘tzd_ops.get_temp’) drivers/thermal/intel_pch_thermal.c:186:19: warning: initialization from incompatible pointer type [-Wincompatible-pointer-types] .get_trip_temp = pch_get_trip_temp, ^ drivers/thermal/intel_pch_thermal.c:186:19: note: (near initialization for ‘tzd_ops.get_trip_temp’) This fixes it. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
Merge fourth patch-bomb from Andrew Morton: - sys_membarier syscall - seq_file interface changes - a few misc fixups * emailed patches from Andrew Morton <akpm@linux-foundation.org>: revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each" mm/early_ioremap: add explicit #include of asm/early_ioremap.h fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void selftests: enhance membarrier syscall test selftests: add membarrier syscall test sys_membarrier(): system-wide memory barrier (generic, x86) MODSIGN: fix a compilation warning in extract-cert
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Vineet Gupta authored
Newer bitfiles needs the reduced clk even for SMP builds Cc: <stable@vger.kernel.org> #4.2 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://github.com/jonmason/ntbLinus Torvalds authored
Pull NTB fixes from Jon Mason: "NTB bug and documentation fixes, new device IDs, performance improvements, and adding a mailing list to MAINTAINERS for NTB" * tag 'ntb-4.3' of git://github.com/jonmason/ntb: NTB: Fix range check on memory window index NTB: Improve index handling in B2B MW workaround NTB: Fix documentation for ntb_peer_db_clear. NTB: Fix documentation for ntb_link_is_up NTB: Use unique DMA channels for TX and RX NTB: Remove dma_sync_wait from ntb_async_rx NTB: Clean up QP stats info NTB: Make the transport list in order of discovery NTB: Add PCI Device IDs for Broadwell Xeon NTB: Add flow control to the ntb_netdev NTB: Add list to MAINTAINERS
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git://git.kernel.org/pub/scm/linux/kernel/git/dtor/inputLinus Torvalds authored
Pull more input updates from Dmitry Torokhov: "Second round of updates for the input subsystem. This introduces two brand new touchscreen drivers (Colibri and imx6ul_tsc), some small driver fixes, and we are no longer report errors from evdev_flush() as users do not really have a way of handling errors, error codes that we were returning were not on the list of errors supposed to be returned by close(), and errors were causing issues with one of older versions of systemd" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: imx_keypad - remove obsolete comment Input: touchscreen - add imx6ul_tsc driver support Input: Add touchscreen support for Colibri VF50 Input: i8042 - lower log level for "no controller" message Input: evdev - do not report errors form flush() Input: elants_i2c - extend the calibration timeout to 12 seconds Input: sparcspkr - fix module autoload for OF platform drivers Input: regulator-haptic - fix module autoload for OF platform driver Input: pwm-beeper - fix module autoload for OF platform driver Input: ab8500-ponkey - Fix module autoload for OF platform driver Input: cyttsp - remove unnecessary MODULE_ALIAS() Input: elan_i2c - add ACPI ID "ELAN1000"
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
Pull more power management and ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups on top of the previous PM+ACPI pull request (cpufreq core and drivers, cpuidle, generic power domains framework). Some of them didn't make to that pull request and some fix issues introduced by it. The only really new thing is the support for suspend frequency in the cpufreq-dt driver, but it is needed to fix an issue with Exynos platforms. Specifics: - build fix for the new Mediatek MT8173 cpufreq driver (Guenter Roeck). - generic power domains framework fixes (power on error code path, subdomain removal) and cleanup of a deprecated API user (Geert Uytterhoeven, Jon Hunter, Ulf Hansson). - cpufreq-dt driver fixes including two fixes for bugs related to the new Operating Performance Points Device Tree bindings introduced recently (Viresh Kumar). - suspend frequency support for the cpufreq-dt driver (Bartlomiej Zolnierkiewicz, Viresh Kumar). - cpufreq core cleanups (Viresh Kumar). - intel_pstate driver fixes (Chen Yu, Kristen Carlson Accardi). - additional sanity check in the cpuidle core (Xunlei Pang). - fix for a comment related to CPU power management (Lina Iyer)" * tag 'pm+acpi-4.3-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: intel_pstate: fix PCT_TO_HWP macro intel_pstate: Fix user input of min/max to legal policy region PM / OPP: Return suspend_opp only if it is enabled cpufreq-dt: add suspend frequency support cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency PM / OPP: add dev_pm_opp_get_suspend_opp() helper staging: board: Migrate away from __pm_genpd_name_add_device() cpufreq: Use __func__ to print function's name cpufreq: staticize cpufreq_cpu_get_raw() PM / Domains: Ensure subdomain is not in use before removing cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL cpuidle/coupled: Add sanity check for safe_state_index PM / Domains: Try power off masters in error path of __pm_genpd_poweron() cpufreq: dt: Tolerance applies on both sides of target voltage cpufreq: dt: Print error on failing to mark OPPs as shared cpufreq: dt: Check OPP count before marking them shared kernel/cpu_pm: fix cpu_cluster_pm_exit comment
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git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pendingLinus Torvalds authored
Pull SCSI target updates from Nicholas Bellinger: "Here are the outstanding target-pending updates for v4.3-rc1. Mostly bug-fixes and minor changes this round. The fallout from the big v4.2-rc1 RCU conversion have (thus far) been minimal. The highlights this round include: - Move sense handling routines into scsi_common code (Sagi) - Return ABORTED_COMMAND sense key for PI errors (Sagi) - Add tpg_enabled_sendtargets attribute for disabled iscsi-target discovery (David) - Shrink target struct se_cmd by rearranging fields (Roland) - Drop iSCSI use of mutex around max_cmd_sn increment (Roland) - Replace iSCSI __kernel_sockaddr_storage with sockaddr_storage (Andy + Chris) - Honor fabric max_data_sg_nents I/O transfer limit (Arun + Himanshu + nab) - Fix EXTENDED_COPY >= v4.1 regression OOPsen (Alex + nab)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (37 commits) target: use stringify.h instead of own definition target/user: Fix UFLAG_UNKNOWN_OP handling target: Remove no-op conditional target/user: Remove unused variable target: Fix max_cmd_sn increment w/o cmdsn mutex regressions target: Attach EXTENDED_COPY local I/O descriptors to xcopy_pt_sess target/qla2xxx: Honor max_data_sg_nents I/O transfer limit target/iscsi: Replace __kernel_sockaddr_storage with sockaddr_storage target/iscsi: Replace conn->login_ip with login_sockaddr target/iscsi: Keep local_ip as the actual sockaddr target/iscsi: Fix np_ip bracket issue by removing np_ip target: Drop iSCSI use of mutex around max_cmd_sn increment qla2xxx: Update tcm_qla2xxx module description to 24xx+ iscsi-target: Add tpg_enabled_sendtargets for disabled discovery drivers: target: Drop unlikely before IS_ERR(_OR_NULL) target: check DPO/FUA usage for COMPARE AND WRITE target: Shrink struct se_cmd by rearranging fields target: Remove cmd->se_ordered_id (unused except debug log lines) target: add support for START_STOP_UNIT SCSI opcode target: improve unsupported opcode message ...
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull second round of SCSI updates from James Bottomley: "There's one late arriving patch here (added today), fixing a build issue which the scsi_dh patch set in here uncovered. Other than that, everything has been incubated in -next and the checkers for a week. The major pieces of this patch are a set patches facilitating better integration between scsi and scsi_dh (the device handling layer used by multi-path; all the dm parts are acked by Mike Snitzer). This also includes driver updates for mp3sas, scsi_debug and an assortment of bug fixes" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (50 commits) scsi_dh: fix randconfig build error scsi: fix scsi_error_handler vs. scsi_host_dev_release race fcoe: Convert use of __constant_htons to htons mpt2sas: setpci reset kernel oops fix pm80xx: Don't override ts->stat on IO_OPEN_CNX_ERROR_HW_RESOURCE_BUSY lpfc: Fix possible use-after-free and double free in lpfc_mbx_cmpl_rdp_page_a2() bfa: Fix incorrect de-reference of pointer bfa: Fix indentation scsi_transport_sas: Remove check for SAS expander when querying bay/enclosure IDs. scsi_debug: resp_request: remove unused variable scsi_debug: fix REPORT LUNS Well Known LU scsi_debug: schedule_resp fix input variable check scsi_debug: make dump_sector static scsi_debug: vfree is null safe so drop the check scsi_debug: use SCSI_W_LUN_REPORT_LUNS instead of SAM2_WLUN_REPORT_LUNS; scsi_debug: define pr_fmt() for consistent logging mpt2sas: Refcount fw_events and fix unsafe list usage mpt2sas: Refcount sas_device objects and fix unsafe list usage scsi_dh: return SCSI_DH_NOTCONN in scsi_dh_activate() scsi_dh: don't allow to detach device handlers at runtime ...
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- 11 Sep, 2015 23 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediaLinus Torvalds authored
Pull media updates from Mauro Carvalho Chehab: "A series of patches that move part of the code used to allocate memory from the media subsystem to the mm subsystem" [ The mm parts have been acked by VM people, and the series was apparently in -mm for a while - Linus ] * tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames() [media] media: vb2: Remove unused functions [media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector [media] media: vb2: Convert vb2_vmalloc_get_userptr() to use frame vector [media] media: vb2: Convert vb2_dma_sg_get_userptr() to use frame vector [media] vb2: Provide helpers for mapping virtual addresses [media] media: omap_vout: Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns() [media] mm: Provide new get_vaddr_frames() helper [media] vb2: Push mmap_sem down to memops
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edacLinus Torvalds authored
Pull edac updates from Mauro Carvalho Chehab: "Two EDAC fixes for Intel systems (Haswell and Ivy Bridge)" * tag 'edac/v4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac: sb_edac: correctly fetch DIMM width on Ivy Bridge and Haswell sb_edac: look harder for DDRIO on Haswell systems
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git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linuxLinus Torvalds authored
Pull thermal updates from Zhang Rui: - use int instead of unsigned long to represent temperature to avoid bogus overheat detection when negative temperature reported. From Sascha Hauer. - export available thermal governors information to user space via sysfs. From Wei Ni. - introduce new thermal driver for Wildcat Point platform controller hub, which uses PCH thermal sensor and associated critical and hot trip points. From Tushar Dave. - add suuport for Intel Skylake and Denlow platforms in powerclamp driver. - some small cleanups in thermal core. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: thermal: Add Intel PCH thermal driver thermal: Add comment explaining test for critical temperature thermal: Use IS_ENABLED instead of #ifdef thermal: remove unnecessary call to thermal_zone_device_set_polling thermal: trivial: fix typo in comment thermal: consistently use int for temperatures thermal: add available policies sysfs attribute thermal/powerclamp: add cpu id for denlow platform thermal/powerclamp: add cpu id for Skylake u/y thermal/powerclamp: add cpu id for skylake h/s
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Andrew Morton authored
Revert commit f83c7b5e ("ocfs2/dlm: use list_for_each_entry instead of list_for_each"). list_for_each_entry() will dereference its `pos' argument, which can be NULL in dlm_process_recovery_data(). Reported-by: Julia Lawall <julia.lawall@lip6.fr> Reported-by: Fengguang Wu <fengguang.wu@gmail.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Ard Biesheuvel authored
Commit 6b0f68e3 ("mm: add utility for early copy from unmapped ram") introduces a function copy_from_early_mem() into mm/early_ioremap.c which itself calls early_memremap()/early_memunmap(). However, since early_memunmap() has not been declared yet at this point in the .c file, nor by any explicitly included header files, we are depending on a transitive include of asm/early_ioremap.h to declare it, which is fragile. So instead, include this header explicitly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
The seq_<foo> function return values were frequently misused. See: commit 1f33c41c ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") All uses of these return values have been removed, so convert the return types to void. Miscellanea: o Move seq_put_decimal_<type> and seq_escape prototypes closer the other seq_vprintf prototypes o Reorder seq_putc and seq_puts to return early on overflow o Add argument names to seq_vprintf and seq_printf o Update the seq_escape kernel-doc o Convert a couple of leading spaces to tabs in seq_escape Signed-off-by: Joe Perches <joe@perches.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mark Brown <broonie@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Joerg Roedel <jroedel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mathieu Desnoyers authored
Update the membarrier syscall self-test to match the membarrier interface. Extend coverage of the interface. Consider ENOSYS as a "SKIP" test, since it is a valid configuration, but does not allow testing the system call. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pranith Kumar authored
Add a self test for the membarrier system call. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mathieu Desnoyers authored
Here is an implementation of a new system call, sys_membarrier(), which executes a memory barrier on all threads running on the system. It is implemented by calling synchronize_sched(). It can be used to distribute the cost of user-space memory barriers asymmetrically by transforming pairs of memory barriers into pairs consisting of sys_membarrier() and a compiler barrier. For synchronization primitives that distinguish between read-side and write-side (e.g. userspace RCU [1], rwlocks), the read-side can be accelerated significantly by moving the bulk of the memory barrier overhead to the write-side. The existing applications of which I am aware that would be improved by this system call are as follows: * Through Userspace RCU library (http://urcu.so) - DNS server (Knot DNS) https://www.knot-dns.cz/ - Network sniffer (http://netsniff-ng.org/) - Distributed object storage (https://sheepdog.github.io/sheepdog/) - User-space tracing (http://lttng.org) - Network storage system (https://www.gluster.org/) - Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf) - Financial software (https://lkml.org/lkml/2015/3/23/189) Those projects use RCU in userspace to increase read-side speed and scalability compared to locking. Especially in the case of RCU used by libraries, sys_membarrier can speed up the read-side by moving the bulk of the memory barrier cost to synchronize_rcu(). * Direct users of sys_membarrier - core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198) Microsoft core dotnet GC developers are planning to use the mprotect() side-effect of issuing memory barriers through IPIs as a way to implement Windows FlushProcessWriteBuffers() on Linux. They are referring to sys_membarrier in their github thread, specifically stating that sys_membarrier() is what they are looking for. To explain the benefit of this scheme, let's introduce two example threads: Thread A (non-frequent, e.g. executing liburcu synchronize_rcu()) Thread B (frequent, e.g. executing liburcu rcu_read_lock()/rcu_read_unlock()) In a scheme where all smp_mb() in thread A are ordering memory accesses with respect to smp_mb() present in Thread B, we can change each smp_mb() within Thread A into calls to sys_membarrier() and each smp_mb() within Thread B into compiler barriers "barrier()". Before the change, we had, for each smp_mb() pairs: Thread A Thread B previous mem accesses previous mem accesses smp_mb() smp_mb() following mem accesses following mem accesses After the change, these pairs become: Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses As we can see, there are two possible scenarios: either Thread B memory accesses do not happen concurrently with Thread A accesses (1), or they do (2). 1) Non-concurrent Thread A vs Thread B accesses: Thread A Thread B prev mem accesses sys_membarrier() follow mem accesses prev mem accesses barrier() follow mem accesses In this case, thread B accesses will be weakly ordered. This is OK, because at that point, thread A is not particularly interested in ordering them with respect to its own accesses. 2) Concurrent Thread A vs Thread B accesses Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses In this case, thread B accesses, which are ensured to be in program order thanks to the compiler barrier, will be "upgraded" to full smp_mb() by synchronize_sched(). * Benchmarks On Intel Xeon E5405 (8 cores) (one thread is calling sys_membarrier, the other 7 threads are busy looping) 1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call. * User-space user of this system call: Userspace RCU library Both the signal-based and the sys_membarrier userspace RCU schemes permit us to remove the memory barrier from the userspace RCU rcu_read_lock() and rcu_read_unlock() primitives, thus significantly accelerating them. These memory barriers are replaced by compiler barriers on the read-side, and all matching memory barriers on the write-side are turned into an invocation of a memory barrier on all active threads in the process. By letting the kernel perform this synchronization rather than dumbly sending a signal to every process threads (as we currently do), we diminish the number of unnecessary wake ups and only issue the memory barriers on active threads. Non-running threads do not need to execute such barrier anyway, because these are implied by the scheduler context switches. Results in liburcu: Operations in 10s, 6 readers, 2 writers: memory barriers in reader: 1701557485 reads, 2202847 writes signal-based scheme: 9830061167 reads, 6700 writes sys_membarrier: 9952759104 reads, 425 writes sys_membarrier (dyn. check): 7970328887 reads, 425 writes The dynamic sys_membarrier availability check adds some overhead to the read-side compared to the signal-based scheme, but besides that, sys_membarrier slightly outperforms the signal-based scheme. However, this non-expedited sys_membarrier implementation has a much slower grace period than signal and memory barrier schemes. Besides diminishing the number of wake-ups, one major advantage of the membarrier system call over the signal-based scheme is that it does not need to reserve a signal. This plays much more nicely with libraries, and with processes injected into for tracing purposes, for which we cannot expect that signals will be unused by the application. An expedited version of this system call can be added later on to speed up the grace period. Its implementation will likely depend on reading the cpu_curr()->mm without holding each CPU's rq lock. This patch adds the system call to x86 and to asm-generic. [1] http://urcu.so membarrier(2) man page: MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2) NAME membarrier - issue memory barriers on a set of threads SYNOPSIS #include <linux/membarrier.h> int membarrier(int cmd, int flags); DESCRIPTION The cmd argument is one of the following: MEMBARRIER_CMD_QUERY Query the set of supported commands. It returns a bitmask of supported commands. MEMBARRIER_CMD_SHARED Execute a memory barrier on all threads running on the system. Upon return from system call, the caller thread is ensured that all running threads have passed through a state where all memory accesses to user-space addresses match program order between entry to and return from the system call (non-running threads are de facto in such a state). This covers threads from all pro=E2=80=90 cesses running on the system. This command returns 0. The flags argument needs to be 0. For future extensions. All memory accesses performed in program order from each targeted thread is guaranteed to be ordered with respect to sys_membarrier(). If we use the semantic "barrier()" to represent a compiler barrier forcing memory accesses to be performed in program order across the barrier, and smp_mb() to represent explicit memory barriers forcing full memory ordering across the barrier, we have the following ordering table for each pair of barrier(), sys_membarrier() and smp_mb(): The pair ordering is detailed as (O: ordered, X: not ordered): barrier() smp_mb() sys_membarrier() barrier() X X O smp_mb() X O O sys_membarrier() O O O RETURN VALUE On success, these system calls return zero. On error, -1 is returned, and errno is set appropriately. For a given command, with flags argument set to 0, this system call is guaranteed to always return the same value until reboot. ERRORS ENOSYS System call is not implemented. EINVAL Invalid arguments. Linux 2015-04-15 MEMBARRIER(2) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Miell <nmiell@comcast.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Howells authored
Fix the following warning when compiling extract-cert: scripts/extract-cert.c: In function `write_cert': scripts/extract-cert.c:89:2: warning: format not a string literal and no format arguments [-Wformat-security] ERR(!i2d_X509_bio(wb, x509), cert_dst); ^ whereby the ERR() macro is taking cert_dst as the format string. "%s" should be used as the format string as the path could contain special characters. Signed-off-by: David Howells <dhowells@redhat.com> Reported-by: Jim Davis <jim.epost@gmail.com> Acked-by : David Woodhouse <david.woodhouse@intel.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://www.linux-watchdog.org/linux-watchdogLinus Torvalds authored
Pull watchdog updates from Wim Van Sebroeck: - new driver for NXP LPC18xx Watchdog Timer - new driver for SAMA5D4 watchdog timer - add support for MCP79 to nv_tco driver - clean-up and improvement of the mpc8xxx watchdog driver - improvements to gpio-wdt - at91sam9_wdt clock improvements ... and other small fixes and improvements * git://www.linux-watchdog.org/linux-watchdog: (25 commits) Watchdog: Fix parent of watchdog_devices watchdog: at91rm9200: Correct check for syscon_node_to_regmap() errors watchdog: at91sam9: get and use slow clock Documentation: dt: binding: atmel-sama5d4-wdt: for SAMA5D4 watchdog driver watchdog: add a driver to support SAMA5D4 watchdog timer watchdog: mpc8xxx: allow to compile for MPC512x watchdog: mpc8xxx: use better error code when watchdog cannot be enabled watchdog: mpc8xxx: use dynamic memory for device specific data watchdog: mpc8xxx: use devm_ioremap_resource to map memory watchdog: mpc8xxx: make use of of_device_get_match_data watchdog: mpc8xxx: simplify registration watchdog: mpc8xxx: remove dead code watchdog: lpc18xx_wdt_get_timeleft() can be static DT: watchdog: Add NXP LPC18xx Watchdog Timer binding documentation watchdog: NXP LPC18xx Watchdog Timer Driver watchdog: gpio-wdt: ping already at startup for always running devices watchdog: gpio-wdt: be more strict about hw_algo matching Documentation: watchdog: at91sam9_wdt: add clocks property watchdog: booke_wdt: Use infrastructure to check timeout limits watchdog: (nv_tco) add support for MCP79 ...
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Linus Torvalds authored
This reverts commit d353d758. Doing the block layer plug/unplug inside writeback_sb_inodes() is broken, because that function is actually called with a spinlock held: wb->list_lock, as pointed out by Chris Mason. Chris suggested just dropping and re-taking the spinlock around the blk_finish_plug() call (the plgging itself can happen under the spinlock), and that would technically work, but is just disgusting. We do something fairly similar - but not quite as disgusting because we at least have a better reason for it - in writeback_single_inode(), so it's not like the caller can depend on the lock being held over the call, but in this case there just isn't any good reason for that "release and re-take the lock" pattern. [ In general, we should really strive to avoid the "release and retake" pattern for locks, because in the general case it can easily cause subtle bugs when the caller caches any state around the call that might be invalidated by dropping the lock even just temporarily. ] But in this case, the plugging should be easy to just move up to the callers before the spinlock is taken, which should even improve the effectiveness of the plug. So there is really no good reason to play games with locking here. I'll send off a test-patch so that Dave Chinner can verify that that plug movement works. In the meantime this just reverts the problematic commit and adds a comment to the function so that we hopefully don't make this mistake again. Reported-by: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds authored
Pull btrfs cleanups and fixes from Chris Mason: "These are small cleanups, and also some fixes for our async worker thread initialization. I was having some trouble testing these, but it ended up being a combination of changing around my test servers and a shiny new schedule while atomic from the new start/finish_plug in writeback_sb_inodes(). That one only hits on btrfs raid5/6 or MD raid10, and if I wasn't changing a bunch of things in my test setup at once it would have been really clear. Fix for writeback_sb_inodes() on the way as well" * 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: cleanup: remove unnecessary check before btrfs_free_path is called btrfs: async_thread: Fix workqueue 'max_active' value when initializing btrfs: Add raid56 support for updating num_tolerated_disk_barrier_failures in btrfs_balance btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failures btrfs: Remove noused chunk_tree and chunk_objectid from scrub_enumerate_chunks and scrub_chunk btrfs: Update out-of-date "skip parity stripe" comment
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-clientLinus Torvalds authored
Pull Ceph update from Sage Weil: "There are a few fixes for snapshot behavior with CephFS and support for the new keepalive protocol from Zheng, a libceph fix that affects both RBD and CephFS, a few bug fixes and cleanups for RBD from Ilya, and several small fixes and cleanups from Jianpeng and others" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: ceph: improve readahead for file holes ceph: get inode size for each append write libceph: check data_len in ->alloc_msg() libceph: use keepalive2 to verify the mon session is alive rbd: plug rbd_dev->header.object_prefix memory leak rbd: fix double free on rbd_dev->header_name libceph: set 'exists' flag for newly up osd ceph: cleanup use of ceph_msg_get ceph: no need to get parent inode in ceph_open ceph: remove the useless judgement ceph: remove redundant test of head->safe and silence static analysis warnings ceph: fix queuing inode to mdsdir's snaprealm libceph: rename con_work() to ceph_con_workfn() libceph: Avoid holding the zero page on ceph_msgr_slab_init errors libceph: remove the unused macro AES_KEY_SIZE ceph: invalidate dirty pages after forced umount ceph: EIO all operations after forced umount
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git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2Linus Torvalds authored
Pull GFS2 updates from Bob Peterson: "Here is a list of patches we've accumulated for GFS2 for the current upstream merge window. This time we've only got six patches, many of which are very small: - three cleanups from Andreas Gruenbacher, including a nice cleanup of the sequence file code for the sbstats debugfs file. - a patch from Ben Hutchings that changes statistics variables from signed to unsigned. - two patches from me that increase GFS2's glock scalability by switching from a conventional hash table to rhashtable" * tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: A minor "sbstats" cleanup gfs2: Fix a typo in a comment gfs2: Make statistics unsigned, suitable for use with do_div() GFS2: Use resizable hash table for glocks GFS2: Move glock superblock pointer to field gl_name gfs2: Simplify the seq file code for "sbstats"
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Christoph Hellwig authored
It looks like the Kconfig check that was meant to fix this (commit fe9233fb [SCSI] scsi_dh: fix kconfig related build errors) was actually reversed, but no-one noticed until the new set of patches which separated DM and SCSI_DH). Fixes: fe9233fbSigned-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/soundLinus Torvalds authored
Pull sound fixes from Takashi Iwai: "A collection of small fixes since the last update: the HD-audio quirks as usual with a USB-audio fix and a trivial fix for the old sparc driver" * tag 'sound-fix-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: usb-audio: Change internal PCM order ALSA: hda - Fix white noise on Dell M3800 ALSA: hda - Use ALC880_FIXUP_FUJITSU for FSC Amilo M1437 ALSA: hda - Enable headphone jack detect on old Fujitsu laptops ALSA: sparc: amd7930: Fix module autoload for OF platform driver ALSA: hda - Add some FIXUP quirks for white noise on Dell laptop.
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git://people.freedesktop.org/~airlied/linuxLinus Torvalds authored
Pull drm fixes from Dave Airlie: "Just a bunch of fixes to squeeze in before -rc1: - three nouveau regression fixes - one qxl regression fix - a bunch of i915 fixes ... and some core displayport/atomic fixes" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/nouveau/device: enable c800 quirk for tecra w50 drm/nouveau/clk/gt215: Unbreak engine pausing for GT21x/MCP7x drm/nouveau/gr/nv04: fix big endian setting on gr context drm/qxl: validate monitors config modes drm/i915: Allow DSI dual link to be configured on any pipe drm/i915: Don't try to use DDR DVFS on CHV when disabled in the BIOS drm/i915: Fix CSR MMIO address check drm/i915: Limit the number of loops for reading a split 64bit register drm/i915: Fix broken mst get_hw_state. drm/i915: Pass hpd_status_i915[] to intel_get_hpd_pins() in pre-g4x uapi/drm/i915_drm.h: fix userspace compilation. drm/i915: Always mark the object as dirty when used by the GPU drm/dp: Add dp_aux_i2c_speed_khz module param to set the assume i2c bus speed drm/dp: Adjust i2c-over-aux retry count based on message size and i2c bus speed drm/dp: Define AUX_RETRY_INTERVAL as 500 us drm/atomic: Fix bookkeeping with TEST_ONLY, v3.
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Dmitry Torokhov authored
Prepare second round of input updates for 4.3 merge window.
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Rafael J. Wysocki authored
* pm-cpu: kernel/cpu_pm: fix cpu_cluster_pm_exit comment * pm-cpuidle: cpuidle/coupled: Add sanity check for safe_state_index * pm-domains: staging: board: Migrate away from __pm_genpd_name_add_device() PM / Domains: Ensure subdomain is not in use before removing PM / Domains: Try power off masters in error path of __pm_genpd_poweron()
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Rafael J. Wysocki authored
* pm-cpufreq: intel_pstate: fix PCT_TO_HWP macro intel_pstate: Fix user input of min/max to legal policy region cpufreq-dt: add suspend frequency support cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency cpufreq: Use __func__ to print function's name cpufreq: staticize cpufreq_cpu_get_raw() cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL cpufreq: dt: Tolerance applies on both sides of target voltage cpufreq: dt: Print error on failing to mark OPPs as shared cpufreq: dt: Check OPP count before marking them shared
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Rafael J. Wysocki authored
* pm-opp: PM / OPP: Return suspend_opp only if it is enabled PM / OPP: add dev_pm_opp_get_suspend_opp() helper
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David Disseldorp authored
Signed-off-by: David Disseldorp <ddiss@suse.de> Acked-by: Andy Grover <agrover@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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