- 13 Oct, 2016 22 commits
-
-
David Ahern authored
Commit e0d56fdd was a bit aggressive removing l3mdev calls in the IPv4 stack. If the fib_lookup fails we do not want to drop to make_route if the oif is an l3mdev device. Also reverts 19664c6a ("net: l3mdev: Remove netif_index_is_l3_master") which removed netif_index_is_l3_master. Fixes: e0d56fdd ("net: l3mdev: remove redundant calls") Signed-off-by:
David Ahern <dsa@cumulusnetworks.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
-
Andrew Lunn authored
The phy_start() is used to indicate the PHY is now ready to do its work. The state is changed, normally to PHY_UP which means that both the MAC and the PHY are ready. If the phy driver is using polling, when the next poll happens, the state machine notices the PHY is now in PHY_UP, and kicks off auto-negotiation, if needed. If however, the PHY is using interrupts, there is no polling. The phy is stuck in PHY_UP until the next interrupt comes along. And there is no reason for the PHY to interrupt. Have phy_start() schedule the state machine to run, which both speeds up the polling use case, and makes the interrupt use case actually work. This problems exists whenever there is a state change which will not cause an interrupt. Trigger the state machine in these cases, e.g. phy_error(). Signed-off-by:
Andrew Lunn <andrew@lunn.ch> Cc: Kyle Roeschley <kyle.roeschley@ni.com> Tested-by:
Kyle Roeschley <kyle.roeschley@ni.com> Signed-off-by:
-
Eric Dumazet authored
Baozeng Ding reported following KASAN splat : BUG: KASAN: use-after-free in ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 at addr ffff880029c84ec8 Read of size 1 by task poc/25548 Call Trace: [<ffffffff82cf43c9>] dump_stack+0x12e/0x185 /lib/dump_stack.c:15 [< inline >] print_address_description /mm/kasan/report.c:204 [<ffffffff817ced3b>] kasan_report_error+0x48b/0x4b0 /mm/kasan/report.c:283 [< inline >] kasan_report /mm/kasan/report.c:303 [<ffffffff817ced9e>] __asan_report_load1_noabort+0x3e/0x40 /mm/kasan/report.c:321 [<ffffffff85c71da1>] ip6_datagram_recv_specific_ctl+0x13f1/0x15c0 /net/ipv6/datagram.c:687 [<ffffffff85c734c3>] ip6_datagram_recv_ctl+0x33/0x40 [<ffffffff85c0b07c>] do_ipv6_getsockopt.isra.4+0xaec/0x2150 [<ffffffff85c0c7f6>] ipv6_getsockopt+0x116/0x230 [<ffffffff859b5a12>] tcp_getsockopt+0x82/0xd0 /net/ipv4/tcp.c:3035 [<ffffffff855fb385>] sock_common_getsockopt+0x95/0xd0 /net/core/sock.c:2647 [< inline >] SYSC_getsockopt /net/socket.c:1776 [<ffffffff855f8ba2>] SyS_getsockopt+0x142/0x230 /net/socket.c:1758 [<ffffffff8685cdc5>] entry_SYSCALL_64_fastpath+0x23/0xc6 Memory state around the buggy address: ffff880029c84d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff880029c84e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ffff880029c84e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff880029c84f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff880029c84f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff He also provided a syzkaller reproducer. Issue is that ip6_datagram_recv_specific_ctl() expects to find IP6CB data that was moved at a different place in tcp_v6_rcv() This patch moves tcp_v6_restore_cb() up and calls it from tcp_v6_do_rcv() when np->pktoptions is set. Fixes: 971f10ec ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Signed-off-by:Eric Dumazet <edumazet@google.com> Reported-by:
Baozeng Ding <sploving1@gmail.com> Signed-off-by:
-
David S. Miller authored
Based upon v2 of Stephen's patch. Signed-off-by: -
Arnd Bergmann authored
Wiht the latest rework of the xen-netback driver, we get a warning on ARM about the types passed into min(): drivers/net/xen-netback/rx.c: In function 'xenvif_rx_next_chunk': include/linux/kernel.h:739:16: error: comparison of distinct pointer types lacks a cast [-Werror] The reason is that XEN_PAGE_SIZE is not size_t here. There is no actual bug, and we can easily avoid the warning using the min_t() macro instead of min(). Fixes: eb1723a2 ("xen-netback: refactor guest rx") Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
Paul Durrant <paul.durrant@citrix.com> Signed-off-by:
-
Giuseppe CAVALLARO authored
This patch fixes a problem when propagated the failure of ptp_clock_register to open function. Signed-off-by:
Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: Alexandre TORGUE <alexandre.torgue@st.com> Cc: Rayagond Kokatanur <rayagond@vayavyalabs.com> Signed-off-by:
-
Giuseppe CAVALLARO authored
The gmac 4.x version has not extended descriptors (that are available on 3.x instead of). While initializing the PTP module, the advanced PTP was enabled in case of extended descriptors. This cannot be applied for 4.x version where only the hardware capability register has to show if the feature is present. Patch also adds some extra netdev_(debug/inof) to better dump the configuration. Signed-off-by:
-
Arnd Bergmann authored
The definition of qed_get_rdma_ops() is not a prototype unless we add 'void' here, as indicated by this W=1 warning: drivers/net/ethernet/qlogic/qed/qed_roce.c: In function ‘qed_get_rdma_ops’: drivers/net/ethernet/qlogic/qed/qed_roce.c:2950:28: error: old-style function definition [-Werror=old-style-definition] Fixes: abd49676 ("qed: Add RoCE ll2 & GSI support") Signed-off-by:
Yuval Mintz <Yuval.Mintz@caviumnetworks.com> Signed-off-by:
-
stephen hemminger authored
The software calculation of UDP checksum in Netvsc driver was only handling IPv4 case. By using skb_checksum_help() instead all protocols can be handled. Rearrange code to eliminate goto and look like other drivers. This is a temporary solution; recent versions of Window Server etc do support UDP checksum offload, just need to do the appropriate negotiation with host to validate before using. This will be done in later patch. Please queue this for -stable as well. Signed-off-by:
Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by:
-
WANG Cong authored
Krister reported a kernel NULL pointer dereference after tcf_action_init_1() invokes a_o->init(), it is a race condition where one thread calling tcf_register_action() to initialize the netns data after putting act ops in the global list and the other thread searching the list and then calling a_o->init(net, ...). Fix this by moving the pernet ops registration before making the action ops visible. This is fine because: a) we don't rely on act_base in pernet ops->init(), b) in the worst case we have a fully initialized netns but ops is still not ready so new actions still can't be created. Reported-by:
Krister Johansen <kjlx@templeofstupid.com> Tested-by:
Cong Wang <xiyou.wangcong@gmail.com> Acked-by:
Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by:
-
David Vrabel authored
If a VIF has been ready for rx_stall_timeout (60s by default) and an Rx ring is drained of all requests an Rx stall will be incorrectly detected. When this occurs and the guest Rx queue is empty, the Rx ring's event index will not be set and the frontend will not raise an event when new requests are placed on the ring, permanently stalling the VIF. This is a regression introduced by eb1723a2 (xen-netback: refactor guest rx). Fix this by reinstating the setting of queue->last_rx_time when placing a packet onto the guest Rx ring. Signed-off-by:
David Vrabel <david.vrabel@citrix.com> Reviewed-by:
-
Vlad Tsyrklevich authored
The reserved field precise_offset->rsv is not cleared before being copied to user space, leaking kernel stack memory. Clear the struct before it's copied. Signed-off-by:
Vlad Tsyrklevich <vlad@tsyrklevich.net> Acked-by:
Richard Cochran <richardcochran@gmail.com> Signed-off-by:
-
Tom Herbert authored
I am hitting this in mlx5: drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c: In function reclaim_pages_cmd.clone.0: drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c:346: error: call to __compiletime_assert_346 declared with attribute error: BUILD_BUG_ON failed: __mlx5_bit_off(manage_pages_out, pas[i]) % 64 drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c: In function give_pages: drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c:291: error: call to __compiletime_assert_291 declared with attribute error: BUILD_BUG_ON failed: __mlx5_bit_off(manage_pages_in, pas[i]) % 64 Problem is that this is doing a BUILD_BUG_ON on a non-constant expression because of trying to take offset of pas[i] in the structure. Fix is to create MLX5_ARRAY_SET64 that takes an additional argument that is the field index to separate between BUILD_BUG_ON on the array constant field and the indexed field to assign the value to. There are two callers of MLX5_SET64 that are trying to get a variable offset, change those to call MLX5_ARRAY_SET64 passing 'pas' and 'i' as the arguments to use in the offset check and the indexed value assignment. Fixes: a533ed5e ("net/mlx5: Pages management commands via mlx5 ifc") Signed-off-by:
Tom Herbert <tom@herbertland.com> Signed-off-by:
Saeed Mahameed <saeedm@mellanox.com> Signed-off-by:
-
Bjørn Mork authored
The Quectel EC21 and EC25 need the same "set DTR" request as devices based on the MDM9230 chipset, but has no USB3 support. Our best guess is that the "set DTR" functionality depends on chipset and/or baseband firmware generation. But USB3 is still an optional feature. Since we cannot enable this unconditionally for all older devices, and there doesn't appear to be anything we can use in the USB descriptors to identify these chips, we are forced to use a device specific quirk flag. Reported-and-tested-by:
Sebastian Sjoholm <sebastian.sjoholm@gmail.com> Signed-off-by:
Bjørn Mork <bjorn@mork.no> Signed-off-by:
-
David S. Miller authored
Jiri Benc says: ==================== openvswitch: vlan fixes Fix three issues introduced by the 802.1AD patchset. ==================== Signed-off-by: -
Jiri Benc authored
The internal device does support 802.1AD offloading since 018c1dda ("openvswitch: 802.1AD Flow handling, actions, vlan parsing, netlink attributes"). Signed-off-by:
Jiri Benc <jbenc@redhat.com> Acked-by:
Pravin B Shelar <pshelar@ovn.org> Acked-by:
Eric Garver <e@erig.me> Signed-off-by:
-
Jiri Benc authored
When the packet has its vlan tag in skb->vlan_tci, the length of the VLAN header is not counted in skb->len. It doesn't make sense to subtract it. Fixes: 018c1dda ("openvswitch: 802.1AD Flow handling, actions, vlan parsing, netlink attributes") Signed-off-by:
-
Jiri Benc authored
This code is called whenever flow key is being extracted from the packet. The packet may be as likely vlan tagged as not. Fixes: 018c1dda ("openvswitch: 802.1AD Flow handling, actions, vlan parsing, netlink attributes") Signed-off-by:
-
Wei Yongjun authored
Since we will remove items off the list using list_del() we need to use a safe version of the list_for_each_entry() macro aptly named list_for_each_entry_safe(). Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Acked-by:
-
Arnd Bergmann authored
While build testing with randconfig on x86, I ran into this warning that appears to have been around forever drivers/net/ethernet/ti/tlan.c: In function ‘tlan_probe1’: drivers/net/ethernet/ti/tlan.c:614:1: error: label ‘err_out’ defined but not used [-Werror=unused-label] This can be trivially avoided by just moving the label into the existing #ifdef. Signed-off-by:
-
Paul Durrant authored
It is useful to be able to see the hash configuration when running tests. This patch adds a debugfs node for that purpose. The original version of this patch (commit c0c64c15) was reverted due to build failures caused by a conflict with commit 0364a882 ("xen-netback: switch to threaded irq for control ring"). This new version of the patch is nearly identical to the original, the only difference being that creation of the debugfs node is predicated on 'ctrl_irq' being non-zero rather then the now non-existent 'ctrl_task'. Signed-off-by:
Wei Liu <wei.liu2@citrix.com> Signed-off-by:
-
Eric Dumazet authored
There are two ways to get tc filters from kernel to user space. 1) Full dump (tc_dump_tfilter()) 2) RTM_GETTFILTER to get one precise filter, reducing overhead. The second operation is unfortunately broadcasting its result, polluting "tc monitor" users. This patch makes sure only the requester gets the result, using netlink_unicast() instead of rtnetlink_send() Jamal cooked an iproute2 patch to implement "tc filter get" operation, but other user space libraries already use RTM_GETTFILTER when a single filter is queried, instead of dumping all filters. Signed-off-by:
-
- 12 Oct, 2016 3 commits
-
-
Geert Uytterhoeven authored
With m68k-linux-gnu-gcc-4.1: net/strparser/strparser.c: In function ‘strp_recv’: net/strparser/strparser.c:98: warning: ‘err’ may be used uninitialized in this function Pass "len" (which is an error code when negative) instead of the uninitialized "err" variable to fix this. Fixes: 43a0c675 ("strparser: Stream parser for messages") Signed-off-by:Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by:
-
git://people.freedesktop.org/~airlied/linuxLinus Torvalds authored
Pull drm updates from Dave Airlie: "Core: - Fence destaging work - DRIVER_LEGACY to split off legacy drm drivers - drm_mm refactoring - Splitting drm_crtc.c into chunks and documenting better - Display info fixes - rbtree support for prime buffer lookup - Simple VGA DAC driver Panel: - Add Nexus 7 panel - More simple panels i915: - Refactoring GEM naming - Refactored vma/active tracking - Lockless request lookups - Better stolen memory support - FBC fixes - SKL watermark fixes - VGPU improvements - dma-buf fencing support - Better DP dongle support amdgpu: - Powerplay for Iceland asics - Improved GPU reset support - UVD/VEC powergating support for CZ/ST - Preinitialised VRAM buffer support - Virtual display support - Initial SI support - GTT rework - PCI shutdown callback support - HPD IRQ storm fixes amdkfd: - bugfixes tilcdc: - Atomic modesetting support mediatek: - AAL + GAMMA engine support - Hook up gamma LUT - Temporal dithering support imx: - Pixel clock from devicetree - drm bridge support for LVDS bridges - active plane reconfiguration - VDIC deinterlacer support - Frame synchronisation unit support - Color space conversion support analogix: - PSR support - Better panel on/off support rockchip: - rk3399 vop/crtc support - PSR support vc4: - Interlaced vblank timing - 3D rendering CPU overhead reduction - HDMI output fixes tda998x: - HDMI audio ASoC support sunxi: - Allwinner A33 support - better TCON support msm: - DT binding cleanups - Explicit fence-fd support sti: - remove sti415/416 support etnaviv: - MMUv2 refactoring - GC3000 support exynos: - Refactoring HDMI DCC/PHY - G2D pm regression fix - Page fault issues with wait for vblank There is no nouveau work in this tree, as Ben didn't get a pull request in, and he was fighting moving to atomic and adding mst support, so maybe best it waits for a cycle" * tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux: (1412 commits) drm/crtc: constify drm_crtc_index parameter drm/i915: Fix conflict resolution from backmerge of v4.8-rc8 to drm-next drm/i915/guc: Unwind GuC workqueue reservation if request construction fails drm/i915: Reset the breadcrumbs IRQ more carefully drm/i915: Force relocations via cpu if we run out of idle aperture drm/i915: Distinguish last emitted request from last submitted request drm/i915: Allow DP to work w/o EDID drm/i915: Move long hpd handling into the hotplug work drm/i915/execlists: Reinitialise context image after GPU hang drm/i915: Use correct index for backtracking HUNG semaphores drm/i915: Unalias obj->phys_handle and obj->userptr drm/i915: Just clear the mmiodebug before a register access drm/i915/gen9: only add the planes actually affected by ddb changes drm/i915: Allow PCH DPLL sharing regardless of DPLL_SDVO_HIGH_SPEED drm/i915/bxt: Fix HDMI DPLL configuration drm/i915/gen9: fix the watermark res_blocks value drm/i915/gen9: fix plane_blocks_per_line on watermarks calculations drm/i915/gen9: minimum scanlines for Y tile is not always 4 drm/i915/gen9: fix the WaWmMemoryReadLatency implementation drm/i915/kbl: KBL also needs to run the SAGV code ...
-
Linus Torvalds authored
Merge more updates from Andrew Morton: - a few block updates that fell in my lap - lib/ updates - checkpatch - autofs - ipc - a ton of misc other things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits) mm: split gfp_mask and mapping flags into separate fields fs: use mapping_set_error instead of opencoded set_bit treewide: remove redundant #include <linux/kconfig.h> hung_task: allow hung_task_panic when hung_task_warnings is 0 kthread: add kerneldoc for kthread_create() kthread: better support freezable kthread workers kthread: allow to modify delayed kthread work kthread: allow to cancel kthread work kthread: initial support for delayed kthread work kthread: detect when a kthread work is used by more workers kthread: add kthread_destroy_worker() kthread: add kthread_create_worker*() kthread: allow to call __kthread_create_on_node() with va_list args kthread/smpboot: do not park in kthread_create_on_cpu() kthread: kthread worker API cleanup kthread: rename probe_kthread_data() to kthread_probe_data() scripts/tags.sh: enable code completion in VIM mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping kdump, vmcoreinfo: report memory sections virtual addresses ipc/sem.c: add cond_resched in exit_sme ...
-
- 11 Oct, 2016 15 commits
-
-
Michal Hocko authored
mapping->flags currently encodes two different things into a single flag. It contains sticky gfp_mask for page cache allocations and AS_ codes used to report errors/enospace and other states which are mapping specific. Condensing the two semantically unrelated things saves few bytes but it also complicates other things. For one thing the gfp flags space is reduced and in fact we are already running out of available bits. It can be assumed that more gfp flags will be necessary later on. To not introduce the address_space grow (at least on x86_64) we can stick it right after private_lock because we have a hole there. struct address_space { struct inode * host; /* 0 8 */ struct radix_tree_root page_tree; /* 8 16 */ spinlock_t tree_lock; /* 24 4 */ atomic_t i_mmap_writable; /* 28 4 */ struct rb_root i_mmap; /* 32 8 */ struct rw_semaphore i_mmap_rwsem; /* 40 40 */ /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */ long unsigned int nrpages; /* 80 8 */ long unsigned int nrexceptional; /* 88 8 */ long unsigned int writeback_index; /* 96 8 */ const struct address_space_operations * a_ops; /* 104 8 */ long unsigned int flags; /* 112 8 */ spinlock_t private_lock; /* 120 4 */ /* XXX 4 bytes hole, try to pack */ /* --- cacheline 2 boundary (128 bytes) --- */ struct list_head private_list; /* 128 16 */ void * private_data; /* 144 8 */ /* size: 152, cachelines: 3, members: 14 */ /* sum members: 148, holes: 1, sum holes: 4 */ /* last cacheline: 24 bytes */ }; Link: http://lkml.kernel.org/r/20160912114852.GI14524@dhcp22.suse.czSigned-off-by:Michal Hocko <mhocko@suse.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
Michal Hocko authored
The mapping_set_error() helper sets the correct AS_ flag for the mapping so there is no reason to open code it. Use the helper directly. [akpm@linux-foundation.org: be honest about conversion from -ENXIO to -EIO] Link: http://lkml.kernel.org/r/20160912111608.2588-2-mhocko@kernel.orgSigned-off-by:
-
Masahiro Yamada authored
Kernel source files need not include <linux/kconfig.h> explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by:
-
John Siddle authored
Previously hung_task_panic would not be respected if enabled after hung_task_warnings had already been decremented to 0. Permit the kernel to panic if hung_task_panic is enabled after hung_task_warnings has already been decremented to 0 and another task hangs for hung_task_timeout_secs seconds. Check if hung_task_panic is enabled so we don't return prematurely, and check if hung_task_warnings is non-zero so we don't print the warning unnecessarily. [akpm@linux-foundation.org: fix off-by-one] Link: http://lkml.kernel.org/r/1473450214-4049-1-git-send-email-jsiddle@redhat.comSigned-off-by:
John Siddle <jsiddle@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by:
-
Jonathan Corbet authored
This macro is referenced in other kerneldoc comments, but lacks one of its own; fix that. Link: http://lkml.kernel.org/r/20160826072313.726a3485@lwn.netSigned-off-by:
Jonathan Corbet <corbet@lwn.net> Reported-by:
Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by:
-
Petr Mladek authored
This patch allows to make kthread worker freezable via a new @flags parameter. It will allow to avoid an init work in some kthreads. It currently does not affect the function of kthread_worker_fn() but it might help to do some optimization or fixes eventually. I currently do not know about any other use for the @flags parameter but I believe that we will want more flags in the future. Finally, I hope that it will not cause confusion with @flags member in struct kthread. Well, I guess that we will want to rework the basic kthreads implementation once all kthreads are converted into kthread workers or workqueues. It is possible that we will merge the two structures. Link: http://lkml.kernel.org/r/1470754545-17632-12-git-send-email-pmladek@suse.comSigned-off-by:
Petr Mladek <pmladek@suse.com> Acked-by:
Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
-
Petr Mladek authored
There are situations when we need to modify the delay of a delayed kthread work. For example, when the work depends on an event and the initial delay means a timeout. Then we want to queue the work immediately when the event happens. This patch implements kthread_mod_delayed_work() as inspired workqueues. It cancels the timer, removes the work from any worker list and queues it again with the given timeout. A very special case is when the work is being canceled at the same time. It might happen because of the regular kthread_cancel_delayed_work_sync() or by another kthread_mod_delayed_work(). In this case, we do nothing and let the other operation win. This should not normally happen as the caller is supposed to synchronize these operations a reasonable way. Link: http://lkml.kernel.org/r/1470754545-17632-11-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
We are going to use kthread workers more widely and sometimes we will need to make sure that the work is neither pending nor running. This patch implements cancel_*_sync() operations as inspired by workqueues. Well, we are synchronized against the other operations via the worker lock, we use del_timer_sync() and a counter to count parallel cancel operations. Therefore the implementation might be easier. First, we check if a worker is assigned. If not, the work has newer been queued after it was initialized. Second, we take the worker lock. It must be the right one. The work must not be assigned to another worker unless it is initialized in between. Third, we try to cancel the timer when it exists. The timer is deleted synchronously to make sure that the timer call back is not running. We need to temporary release the worker->lock to avoid a possible deadlock with the callback. In the meantime, we set work->canceling counter to avoid any queuing. Fourth, we try to remove the work from a worker list. It might be the list of either normal or delayed works. Fifth, if the work is running, we call kthread_flush_work(). It might take an arbitrary time. We need to release the worker-lock again. In the meantime, we again block any queuing by the canceling counter. As already mentioned, the check for a pending kthread work is done under a lock. In compare with workqueues, we do not need to fight for a single PENDING bit to block other operations. Therefore we do not suffer from the thundering storm problem and all parallel canceling jobs might use kthread_flush_work(). Any queuing is blocked until the counter gets zero. Link: http://lkml.kernel.org/r/1470754545-17632-10-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
We are going to use kthread_worker more widely and delayed works will be pretty useful. The implementation is inspired by workqueues. It uses a timer to queue the work after the requested delay. If the delay is zero, the work is queued immediately. In compare with workqueues, each work is associated with a single worker (kthread). Therefore the implementation could be much easier. In particular, we use the worker->lock to synchronize all the operations with the work. We do not need any atomic operation with a flags variable. In fact, we do not need any state variable at all. Instead, we add a list of delayed works into the worker. Then the pending work is listed either in the list of queued or delayed works. And the existing check of pending works is the same even for the delayed ones. A work must not be assigned to another worker unless reinitialized. Therefore the timer handler might expect that dwork->work->worker is valid and it could simply take the lock. We just add some sanity checks to help with debugging a potential misuse. Link: http://lkml.kernel.org/r/1470754545-17632-9-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
Nothing currently prevents a work from queuing for a kthread worker when it is already running on another one. This means that the work might run in parallel on more than one worker. Also some operations are not reliable, e.g. flush. This problem will be even more visible after we add kthread_cancel_work() function. It will only have "work" as the parameter and will use worker->lock to synchronize with others. Well, normally this is not a problem because the API users are sane. But bugs might happen and users also might be crazy. This patch adds a warning when we try to insert the work for another worker. It does not fully prevent the misuse because it would make the code much more complicated without a big benefit. It adds the same warning also into kthread_flush_work() instead of the repeated attempts to get the right lock. A side effect is that one needs to explicitly reinitialize the work if it must be queued into another worker. This is needed, for example, when the worker is stopped and started again. It is a bit inconvenient. But it looks like a good compromise between the stability and complexity. I have double checked all existing users of the kthread worker API and they all seems to initialize the work after the worker gets started. Just for completeness, the patch adds a check that the work is not already in a queue. The patch also puts all the checks into a separate function. It will be reused when implementing delayed works. Link: http://lkml.kernel.org/r/1470754545-17632-8-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
The current kthread worker users call flush() and stop() explicitly. This function does the same plus it frees the kthread_worker struct in one call. It is supposed to be used together with kthread_create_worker*() that allocates struct kthread_worker. Link: http://lkml.kernel.org/r/1470754545-17632-7-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
Kthread workers are currently created using the classic kthread API, namely kthread_run(). kthread_worker_fn() is passed as the @threadfn parameter. This patch defines kthread_create_worker() and kthread_create_worker_on_cpu() functions that hide implementation details. They enforce using kthread_worker_fn() for the main thread. But I doubt that there are any plans to create any alternative. In fact, I think that we do not want any alternative main thread because it would be hard to support consistency with the rest of the kthread worker API. The naming and function of kthread_create_worker() is inspired by the workqueues API like the rest of the kthread worker API. The kthread_create_worker_on_cpu() variant is motivated by the original kthread_create_on_cpu(). Note that we need to bind per-CPU kthread workers already when they are created. It makes the life easier. kthread_bind() could not be used later for an already running worker. This patch does _not_ convert existing kthread workers. The kthread worker API need more improvements first, e.g. a function to destroy the worker. IMPORTANT: kthread_create_worker_on_cpu() allows to use any format of the worker name, in compare with kthread_create_on_cpu(). The good thing is that it is more generic. The bad thing is that most users will need to pass the cpu number in two parameters, e.g. kthread_create_worker_on_cpu(cpu, "helper/%d", cpu). To be honest, the main motivation was to avoid the need for an empty va_list. The only legal way was to create a helper function that would be called with an empty list. Other attempts caused compilation warnings or even errors on different architectures. There were also other alternatives, for example, using #define or splitting __kthread_create_worker(). The used solution looked like the least ugly. Link: http://lkml.kernel.org/r/1470754545-17632-6-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
kthread_create_on_node() implements a bunch of logic to create the kthread. It is already called by kthread_create_on_cpu(). We are going to extend the kthread worker API and will need to call kthread_create_on_node() with va_list args there. This patch does only a refactoring and does not modify the existing behavior. Link: http://lkml.kernel.org/r/1470754545-17632-5-git-send-email-pmladek@suse.comSigned-off-by:
-
Petr Mladek authored
kthread_create_on_cpu() was added by the commit 2a1d4460 ("kthread: Implement park/unpark facility"). It is currently used only when enabling new CPU. For this purpose, the newly created kthread has to be parked. The CPU binding is a bit tricky. The kthread is parked when the CPU has not been allowed yet. And the CPU is bound when the kthread is unparked. The function would be useful for more per-CPU kthreads, e.g. bnx2fc_thread, fcoethread. For this purpose, the newly created kthread should stay in the uninterruptible state. This patch moves the parking into smpboot. It binds the thread already when created. Then the function might be used universally. Also the behavior is consistent with kthread_create() and kthread_create_on_node(). Link: http://lkml.kernel.org/r/1470754545-17632-4-git-send-email-pmladek@suse.comSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
-
Petr Mladek authored
A good practice is to prefix the names of functions by the name of the subsystem. The kthread worker API is a mix of classic kthreads and workqueues. Each worker has a dedicated kthread. It runs a generic function that process queued works. It is implemented as part of the kthread subsystem. This patch renames the existing kthread worker API to use the corresponding name from the workqueues API prefixed by kthread_: __init_kthread_worker() -> __kthread_init_worker() init_kthread_worker() -> kthread_init_worker() init_kthread_work() -> kthread_init_work() insert_kthread_work() -> kthread_insert_work() queue_kthread_work() -> kthread_queue_work() flush_kthread_work() -> kthread_flush_work() flush_kthread_worker() -> kthread_flush_worker() Note that the names of DEFINE_KTHREAD_WORK*() macros stay as they are. It is common that the "DEFINE_" prefix has precedence over the subsystem names. Note that INIT() macros and init() functions use different naming scheme. There is no good solution. There are several reasons for this solution: + "init" in the function names stands for the verb "initialize" aka "initialize worker". While "INIT" in the macro names stands for the noun "INITIALIZER" aka "worker initializer". + INIT() macros are used only in DEFINE() macros + init() functions are used close to the other kthread() functions. It looks much better if all the functions use the same scheme. + There will be also kthread_destroy_worker() that will be used close to kthread_cancel_work(). It is related to the init() function. Again it looks better if all functions use the same naming scheme. + there are several precedents for such init() function names, e.g. amd_iommu_init_device(), free_area_init_node(), jump_label_init_type(), regmap_init_mmio_clk(), + It is not an argument but it was inconsistent even before. [arnd@arndb.de: fix linux-next merge conflict] Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.comSuggested-by:
-
