- 30 Mar, 2020 32 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linuxSaeed Mahameed authored
* 'mlx5-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux: mlx5: Remove uninitialized use of key in mlx5_core_create_mkey {IB,net}/mlx5: Move asynchronous mkey creation to mlx5_ib {IB,net}/mlx5: Assign mkey variant in mlx5_ib only {IB,net}/mlx5: Setup mkey variant before mr create command invocation Signed-off-by:
Saeed Mahameed <saeedm@mellanox.com>
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David S. Miller authored
Mat Martineau says: ==================== Multipath TCP part 3: Multiple subflows and path management v2 -> v3: Remove 'inline' in .c files, fix uapi bit macros, and rebase. v1 -> v2: Rebase on current net-next, fix for netlink limit setting, and update .gitignore for selftest. This patch set allows more than one TCP subflow to be established and used for a multipath TCP connection. Subflows are added to an existing connection using the MP_JOIN option during the 3-way handshake. With multiple TCP subflows available, sent data is now stored in the MPTCP socket so it may be retransmitted on any TCP subflow if there is no DATA_ACK before a timeout. If an MPTCP-level timeout occurs, data is retransmitted using an available subflow. Storing this sent data requires the addition of memory accounting at the MPTCP level, which was previously delegated to the single subflow. Incoming DATA_ACKs now free data from the MPTCP-level retransmit buffer. IP addresses available for new subflow connections can now be advertised and received with the ADD_ADDR option, and the corresponding REMOVE_ADDR option likewise advertises that an address is no longer available. The MPTCP path manager netlink interface has commands to set in-kernel limits for the number of concurrent subflows and control the advertisement of IP addresses between peers. To track and debug MPTCP connections there are new MPTCP MIB counters, and subflow context can be requested using inet_diag. The MPTCP self-tests now validate multiple-subflow operation and the netlink path manager interface. ==================== Signed-off-by:David S. Miller <davem@davemloft.net>
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Paolo Abeni authored
Use the pm netlink to configure the creation of several subflows, and verify that via MIB counters. Update the mptcp_connect program to allow reliable MP_JOIN handshake even on small data file Signed-off-by:
Paolo Abeni <pabeni@redhat.com> Signed-off-by:
Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by:
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Paolo Abeni authored
This introduces basic self-tests for the PM netlink, checking the basic APIs and possible exceptional values. Signed-off-by:
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Paolo Abeni authored
Expose a new netlink family to userspace to control the PM, setting: - list of local addresses to be signalled. - list of local addresses used to created subflows. - maximum number of add_addr option to react When the msk is fully established, the PM netlink attempts to announce the 'signal' list via the ADD_ADDR option. Since we currently lack the ADD_ADDR echo (and related event) only the first addr is sent. After exhausting the 'announce' list, the PM tries to create subflow for each addr in 'local' list, waiting for each connection to be completed before attempting the next one. Idea is to add an additional PM hook for ADD_ADDR echo, to allow the PM netlink announcing multiple addresses, in sequence. Co-developed-by:
Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by:
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Florian Westphal authored
Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s" or "nstat" will show them automatically. The MPTCP MIB counters are allocated in a distinct pcpu area in order to avoid bloating/wasting TCP pcpu memory. Counters are allocated once the first MPTCP socket is created in a network namespace and free'd on exit. If no sockets have been allocated, all-zero mptcp counters are shown. The MIB counter list is taken from the multipath-tcp.org kernel, but only a few counters have been picked up so far. The counter list can be increased at any time later on. v2 -> v3: - remove 'inline' in foo.c files (David S. Miller) Co-developed-by:
Florian Westphal <fw@strlen.de> Signed-off-by:
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Davide Caratti authored
add ulp-specific diagnostic functions, so that subflow information can be dumped to userspace programs like 'ss'. v2 -> v3: - uapi: use bit macros appropriate for userspace Co-developed-by:
Davide Caratti <dcaratti@redhat.com> Signed-off-by:
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Paolo Abeni authored
On timeout event, schedule a work queue to do the retransmission. Retransmission code closely resembles the sendmsg() implementation and re-uses mptcp_sendmsg_frag, providing a dummy msghdr - for flags' sake - and peeking the relevant dfrag from the rtx head. Signed-off-by:
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Paolo Abeni authored
This will simplify mptcp-level retransmission implementation in the next patch. If dfrag is provided by the caller, skip kernel space memory allocation and use data and metadata provided by the dfrag itself. Because a peer could ack data at TCP level but refrain from sending mptcp-level ACKs, we could grow the mptcp socket backlog indefinitely. We should thus block mptcp_sendmsg until the peer has acked some of the sent data. In order to be able to do so, increment the mptcp socket wmem_queued counter on memory allocation and decrement it when releasing the memory on mptcp-level ack reception. Because TCP performns sndbuf auto-tuning up to tcp_wmem_max[2], make this the mptcp sk_sndbuf limit. In the future we could add experiment with autotuning as TCP does in tcp_sndbuf_expand(). v2 -> v3: - remove 'inline' in foo.c files (David S. Miller) Co-developed-by:
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Florian Westphal authored
After adding wmem accounting for the mptcp socket we could get into a situation where the mptcp socket can't transmit more data, and mptcp_clean_una doesn't reduce wmem even if snd_una has advanced because it currently will only remove entire dfrags. Allow advancing the dfrag head sequence and reduce wmem, even though this isn't correct (as we can't release the page). Because we will soon block on mptcp sk in case wmem is too large, call sk_stream_write_space() in case we reduced the backlog so userspace task blocked in sendmsg or poll will be woken up. This isn't an issue if the send buffer is large, but it is when SO_SNDBUF is used to reduce it to a lower value. Note we can still get a deadlock for low SO_SNDBUF values in case both sides of the connection write to the socket: both could be blocked due to wmem being too small -- and current mptcp stack will only increment mptcp ack_seq on recv. This doesn't happen with the selftest as it uses poll() and will always call recv if there is data to read. Signed-off-by:
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Paolo Abeni authored
Charge the data on the rtx queue to the master MPTCP socket, too. Such memory in uncharged when the data is acked/dequeued. Also account mptcp sockets inuse via a protocol specific pcpu counter. Co-developed-by:
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Paolo Abeni authored
The timer will be used to schedule retransmission. It's frequency is based on the current subflow RTO estimation and is reset on every una_seq update The timer is clearer for good by __mptcp_clear_xmit() Also clean MPTCP rtx queue before each transmission. Signed-off-by:
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Paolo Abeni authored
Keep the send page fragment on an MPTCP level retransmission queue. The queue entries are allocated inside the page frag allocator, acquiring an additional reference to the page for each list entry. Also switch to a custom page frag refill function, to ensure that the current page fragment can always host an MPTCP rtx queue entry. The MPTCP rtx queue is flushed at disconnect() and close() time Note that now we need to call __mptcp_init_sock() regardless of mptcp enable status, as the destructor will try to walk the rtx_queue. v2 -> v3: - remove 'inline' in foo.c files (David S. Miller) Signed-off-by:
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Paolo Abeni authored
So that we keep per unacked sequence number consistent; since we update per msk data, use an atomic64 cmpxchg() to protect against concurrent updates from multiple subflows. Initialize the snd_una at connect()/accept() time. Co-developed-by:
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Peter Krystad authored
Fill in more path manager functionality by adding a worker function and modifying the related stub functions to schedule the worker. Co-developed-by:
Peter Krystad <peter.krystad@linux.intel.com> Signed-off-by:
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Peter Krystad authored
Subflow creation may be initiated by the path manager when the primary connection is fully established and a remote address has been received via ADD_ADDR. Create an in-kernel sock and use kernel_connect() to initiate connection. Passive sockets can't acquire the mptcp socket lock at subflow creation time, so an additional list protected by a new spinlock is used to track the MPJ subflows. Such list is spliced into conn_list tail every time the msk socket lock is acquired, so that it will not interfere with data flow on the original connection. Data flow and connection failover not addressed by this commit. Co-developed-by:
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Peter Krystad authored
Process the MP_JOIN option in a SYN packet with the same flow as MP_CAPABLE but when the third ACK is received add the subflow to the MPTCP socket subflow list instead of adding it to the TCP socket accept queue. The subflow is added at the end of the subflow list so it will not interfere with the existing subflows operation and no data is expected to be transmitted on it. Co-developed-by:
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Peter Krystad authored
Add enough of a path manager interface to allow sending of ADD_ADDR when an incoming MPTCP connection is created. Capable of sending only a single IPv4 ADD_ADDR option. The 'pm_data' element of the connection sock will need to be expanded to handle multiple interfaces and IPv6. Partial processing of the incoming ADD_ADDR is included so the path manager notification of that event happens at the proper time, which involves validating the incoming address information. This is a skeleton interface definition for events generated by MPTCP. Co-developed-by:
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Peter Krystad authored
Add handling for sending and receiving the ADD_ADDR, ADD_ADDR6, and RM_ADDR suboptions. Co-developed-by:
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Jacob Keller authored
A recent commit e8937681 ("devlink: prepare to support region operations") used the region_cr_space_str and region_fw_health_str variables as initializers for the devlink_region_ops structures. This can result in compiler errors: drivers/net/ethernet/mellanox//mlx4/crdump.c:45:10: error: initializer element is not constant .name = region_cr_space_str, ^ drivers/net/ethernet/mellanox//mlx4/crdump.c:45:10: note: (near initialization for ‘region_cr_space_ops.name’) drivers/net/ethernet/mellanox//mlx4/crdump.c:50:10: error: initializer element is not constant .name = region_fw_health_str, The variables were made to be "const char * const", indicating that both the pointer and data were constant. This was enough to resolve this on recent GCC (gcc (GCC) 9.2.1 20190827 (Red Hat 9.2.1-1) for this author). Unfortunately this is not enough for older compilers to realize that the variable can be treated as a constant expression. Fix this by introducing macros for the string and use those instead of the variable name in the region ops structures. Reported-by:
tanhuazhong <tanhuazhong@huawei.com> Fixes: e8937681 ("devlink: prepare to support region operations") Signed-off-by:
Jacob Keller <jacob.e.keller@intel.com> Reviewed-by:
Leon Romanovsky <leonro@mellanox.com> Signed-off-by:
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Jacob Keller authored
The devlink-region.rst and ice-region.rst documentation files wrapped some lines within shell code blocks due to being longer than 80 lines. It was pointed out during review that wrapping these lines shouldn't be done. Fix these two rST files and remove the line wrapping on these shell command examples. Reported-by:
Jiri Pirko <jiri@resnulli.us> Signed-off-by:
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René van Dorst authored
Convert the mt7530 switch driver to use the finalised link parameters in mac_link_up() rather than the parameters in mac_config(). Signed-off-by:
René van Dorst <opensource@vdorst.com> Tested-by:
Sean Wang <sean.wang@mediatek.com> Signed-off-by:
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Vladimir Oltean authored
It looks like the P/Q/R/S series supports some more counters, generically named "Ethernet statistics counter", which we were not printing. Add them. Signed-off-by:
Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by:
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Julian Wiedmann authored
Enable the L3 driver's IPv4 address notifier to watch for events on qeth devices that have been moved into a net namespace. We need to program those IPs into the HW just as usual, otherwise inbound traffic won't flow. Fixes: 6133fb1a ("[NETNS]: Disable inetaddr notifiers in namespaces other than initial.") Signed-off-by:
Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by:
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Cambda Zhu authored
The SKB_SGO_CB_OFFSET should be SKB_GSO_CB_OFFSET which means the offset of the GSO in skb cb. This patch fixes the typo. Fixes: 9207f9d4 ("net: preserve IP control block during GSO segmentation") Signed-off-by:
Cambda Zhu <cambda@linux.alibaba.com> Signed-off-by:
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Yuval Basson authored
Calling queue_delayed_work concurrently with destroy_workqueue might race to an unexpected outcome - scheduled task after wq is destroyed or other resources (like ptt_pool) are freed (yields NULL pointer dereference). cancel_delayed_work prevents the race by cancelling the timer triggered for scheduling a new task. Fixes: 59ccf86f ("qed: Add driver infrastucture for handling mfw requests") Signed-off-by:
Denis Bolotin <dbolotin@marvell.com> Signed-off-by:
Michal Kalderon <mkalderon@marvell.com> Signed-off-by:
Yuval Basson <ybason@marvell.com> Signed-off-by:
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Denis Kirjanov authored
page pool API can be useful for non-DMA cases like xen-netfront driver so let's allow to pass zero flags to page pool flags. v2: check DMA direction only if PP_FLAG_DMA_MAP is set Signed-off-by:
Denis Kirjanov <kda@linux-powerpc.org> Acked-by:
Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by:
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Jian Yang authored
For historical reasons, there are several timestamping selftest targets in selftests/networking/timestamping. Move them to the standard directory for networking tests: selftests/net. Signed-off-by:
Jian Yang <jianyang@google.com> Acked-by:
Willem de Bruijn <willemb@google.com> Acked-by:
Jakub Kicinski <kuba@kernel.org> Signed-off-by:
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Philippe Schenker authored
Until now a PHY-fixup in mach-imx set our rgmii timing correctly. For the PHY KSZ9131 there is no PHY-fixup in mach-imx. To support this PHY too, use rgmii-id. For the now used KSZ9031 nothing will change, as rgmii-id is only implemented and supported by the KSZ9131. Signed-off-by:
Philippe Schenker <philippe.schenker@toradex.com> Signed-off-by:
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Philippe Schenker authored
The KSZ9131 provides DLL controlled delays on RXC and TXC lines. This patch makes use of those delays. The information which delays should be enabled or disabled comes from the interface names, documented in ethernet-controller.yaml: rgmii: Disable RXC and TXC delays rgmii-id: Enable RXC and TXC delays rgmii-txid: Enable only TXC delay, disable RXC delay rgmii-rxid: Enable onlx RXC delay, disable TXC delay Signed-off-by:
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Mark Starovoytov authored
This patch adds new netlink attribute to allow a user to (optionally) specify the desired offload mode immediately upon MACSec link creation. Separate iproute patch will be required to support this from user space. Signed-off-by:
Mark Starovoytov <mstarovoitov@marvell.com> Signed-off-by:
Igor Russkikh <irusskikh@marvell.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller authored
Minor comment conflict in mac80211. Signed-off-by:
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- 29 Mar, 2020 8 commits
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Linus Torvalds authored
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Linus Torvalds authored
Merge vm fixes from Andrew Morton: "5 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm/sparse: fix kernel crash with pfn_section_valid check mm: fork: fix kernel_stack memcg stats for various stack implementations hugetlb_cgroup: fix illegal access to memory drivers/base/memory.c: indicate all memory blocks as removable mm/swapfile.c: move inode_lock out of claim_swapfile
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer fix from Thomas Gleixner: "A single fix for the Hyper-V clocksource driver to make sched clock actually return nanoseconds and not the virtual clock value which increments at 10e7 HZ (100ns)" * tag 'timers-urgent-2020-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/hyper-v: Make sched clock return nanoseconds correctly
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull irq fix from Thomas Gleixner: "A single bugfix to prevent reference leaks in irq affinity notifiers" * tag 'irq-urgent-2020-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Fix reference leaks on irq affinity notifiers
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Aneesh Kumar K.V authored
Fix the crash like this: BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc000000000c3447c Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries CPU: 11 PID: 7519 Comm: lt-ndctl Not tainted 5.6.0-rc7-autotest #1 ... NIP [c000000000c3447c] vmemmap_populated+0x98/0xc0 LR [c000000000088354] vmemmap_free+0x144/0x320 Call Trace: section_deactivate+0x220/0x240 __remove_pages+0x118/0x170 arch_remove_memory+0x3c/0x150 memunmap_pages+0x1cc/0x2f0 devm_action_release+0x30/0x50 release_nodes+0x2f8/0x3e0 device_release_driver_internal+0x168/0x270 unbind_store+0x130/0x170 drv_attr_store+0x44/0x60 sysfs_kf_write+0x68/0x80 kernfs_fop_write+0x100/0x290 __vfs_write+0x3c/0x70 vfs_write+0xcc/0x240 ksys_write+0x7c/0x140 system_call+0x5c/0x68 The crash is due to NULL dereference at test_bit(idx, ms->usage->subsection_map); due to ms->usage = NULL in pfn_section_valid() With commit d41e2f3b ("mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case") section_mem_map is set to NULL after depopulate_section_mem(). This was done so that pfn_page() can work correctly with kernel config that disables SPARSEMEM_VMEMMAP. With that config pfn_to_page does __section_mem_map_addr(__sec) + __pfn; where static inline struct page *__section_mem_map_addr(struct mem_section *section) { unsigned long map = section->section_mem_map; map &= SECTION_MAP_MASK; return (struct page *)map; } Now with SPASEMEM_VMEMAP enabled, mem_section->usage->subsection_map is used to check the pfn validity (pfn_valid()). Since section_deactivate release mem_section->usage if a section is fully deactivated, pfn_valid() check after a subsection_deactivate cause a kernel crash. static inline int pfn_valid(unsigned long pfn) { ... return early_section(ms) || pfn_section_valid(ms, pfn); } where static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) { int idx = subsection_map_index(pfn); return test_bit(idx, ms->usage->subsection_map); } Avoid this by clearing SECTION_HAS_MEM_MAP when mem_section->usage is freed. For architectures like ppc64 where large pages are used for vmmemap mapping (16MB), a specific vmemmap mapping can cover multiple sections. Hence before a vmemmap mapping page can be freed, the kernel needs to make sure there are no valid sections within that mapping. Clearing the section valid bit before depopulate_section_memap enables this. [aneesh.kumar@linux.ibm.com: add comment] Link: http://lkml.kernel.org/r/20200326133235.343616-1-aneesh.kumar@linux.ibm.comLink: http://lkml.kernel.org/r/20200325031914.107660-1-aneesh.kumar@linux.ibm.com Fixes: d41e2f3b ("mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case") Reported-by:Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Tested-by:
Baoquan He <bhe@redhat.com> Reviewed-by:
Wei Yang <richard.weiyang@gmail.com> Acked-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Roman Gushchin authored
Depending on CONFIG_VMAP_STACK and the THREAD_SIZE / PAGE_SIZE ratio the space for task stacks can be allocated using __vmalloc_node_range(), alloc_pages_node() and kmem_cache_alloc_node(). In the first and the second cases page->mem_cgroup pointer is set, but in the third it's not: memcg membership of a slab page should be determined using the memcg_from_slab_page() function, which looks at page->slab_cache->memcg_params.memcg . In this case, using mod_memcg_page_state() (as in account_kernel_stack()) is incorrect: page->mem_cgroup pointer is NULL even for pages charged to a non-root memory cgroup. It can lead to kernel_stack per-memcg counters permanently showing 0 on some architectures (depending on the configuration). In order to fix it, let's introduce a mod_memcg_obj_state() helper, which takes a pointer to a kernel object as a first argument, uses mem_cgroup_from_obj() to get a RCU-protected memcg pointer and calls mod_memcg_state(). It allows to handle all possible configurations (CONFIG_VMAP_STACK and various THREAD_SIZE/PAGE_SIZE values) without spilling any memcg/kmem specifics into fork.c . Note: This is a special version of the patch created for stable backports. It contains code from the following two patches: - mm: memcg/slab: introduce mem_cgroup_from_obj() - mm: fork: fix kernel_stack memcg stats for various stack implementations [guro@fb.com: introduce mem_cgroup_from_obj()] Link: http://lkml.kernel.org/r/20200324004221.GA36662@carbon.dhcp.thefacebook.com Fixes: 4d96ba35 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages") Signed-off-by:
Roman Gushchin <guro@fb.com> Signed-off-by:
Shakeel Butt <shakeelb@google.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Bharata B Rao <bharata@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200303233550.251375-1-guro@fb.comSigned-off-by:
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Mina Almasry authored
This appears to be a mistake in commit faced7e0 ("mm: hugetlb controller for cgroups v2"). Essentially that commit does a hugetlb_cgroup_from_counter assuming that page_counter_try_charge has initialized counter. But if that has failed then it seems will not initialize counter, so hugetlb_cgroup_from_counter(counter) ends up pointing to random memory, causing kasan to complain. The solution is to simply use 'h_cg', instead of hugetlb_cgroup_from_counter(counter), since that is a reference to the hugetlb_cgroup anyway. After this change kasan ceases to complain. Fixes: faced7e0 ("mm: hugetlb controller for cgroups v2") Reported-by: syzbot+cac0c4e204952cf449b1@syzkaller.appspotmail.com Signed-off-by:
Mina Almasry <almasrymina@google.com> Signed-off-by:
Giuseppe Scrivano <gscrivan@redhat.com> Acked-by:
Tejun Heo <tj@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/20200313223920.124230-1-almasrymina@google.comSigned-off-by:
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David Hildenbrand authored
We see multiple issues with the implementation/interface to compute whether a memory block can be offlined (exposed via /sys/devices/system/memory/memoryX/removable) and would like to simplify it (remove the implementation). 1. It runs basically lockless. While this might be good for performance, we see possible races with memory offlining that will require at least some sort of locking to fix. 2. Nowadays, more false positives are possible. No arch-specific checks are performed that validate if memory offlining will not be denied right away (and such check will require locking). For example, arm64 won't allow to offline any memory block that was added during boot - which will imply a very high error rate. Other archs have other constraints. 3. The interface is inherently racy. E.g., if a memory block is detected to be removable (and was not a false positive at that time), there is still no guarantee that offlining will actually succeed. So any caller already has to deal with false positives. 4. It is unclear which performance benefit this interface actually provides. The introducing commit 5c755e9f ("memory-hotplug: add sysfs removable attribute for hotplug memory remove") mentioned "A user-level agent must be able to identify which sections of memory are likely to be removable before attempting the potentially expensive operation." However, no actual performance comparison was included. Known users: - lsmem: Will group memory blocks based on the "removable" property. [1] - chmem: Indirect user. It has a RANGE mode where one can specify removable ranges identified via lsmem to be offlined. However, it also has a "SIZE" mode, which allows a sysadmin to skip the manual "identify removable blocks" step. [2] - powerpc-utils: Uses the "removable" attribute to skip some memory blocks right away when trying to find some to offline+remove. However, with ballooning enabled, it already skips this information completely (because it once resulted in many false negatives). Therefore, the implementation can deal with false positives properly already. [3] According to Nathan Fontenot, DLPAR on powerpc is nowadays no longer driven from userspace via the drmgr command (powerpc-utils). Nowadays it's managed in the kernel - including onlining/offlining of memory blocks - triggered by drmgr writing to /sys/kernel/dlpar. So the affected legacy userspace handling is only active on old kernels. Only very old versions of drmgr on a new kernel (unlikely) might execute slower - totally acceptable. With CONFIG_MEMORY_HOTREMOVE, always indicating "removable" should not break any user space tool. We implement a very bad heuristic now. Without CONFIG_MEMORY_HOTREMOVE we cannot offline anything, so report "not removable" as before. Original discussion can be found in [4] ("[PATCH RFC v1] mm: is_mem_section_removable() overhaul"). Other users of is_mem_section_removable() will be removed next, so that we can remove is_mem_section_removable() completely. [1] http://man7.org/linux/man-pages/man1/lsmem.1.html [2] http://man7.org/linux/man-pages/man8/chmem.8.html [3] https://github.com/ibm-power-utilities/powerpc-utils [4] https://lkml.kernel.org/r/20200117105759.27905-1-david@redhat.com Also, this patch probably fixes a crash reported by Steve. http://lkml.kernel.org/r/CAPcyv4jpdaNvJ67SkjyUJLBnBnXXQv686BiVW042g03FUmWLXw@mail.gmail.comReported-by:
"Scargall, Steve" <steve.scargall@intel.com> Suggested-by:
Michal Hocko <mhocko@kernel.org> Signed-off-by:
David Hildenbrand <david@redhat.com> Signed-off-by:
Nathan Fontenot <ndfont@gmail.com> Acked-by:
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