Commit Graph

354 Commits

Author SHA1 Message Date
Johannes Weiner
8b39d20ece sched: psi: fix unprivileged polling against cgroups
519fabc7aa ("psi: remove 500ms min window size limitation for
triggers") breaks unprivileged psi polling on cgroups.

Historically, we had a privilege check for polling in the open() of a
pressure file in /proc, but were erroneously missing it for the open()
of cgroup pressure files.

When unprivileged polling was introduced in d82caa2735 ("sched/psi:
Allow unprivileged polling of N*2s period"), it needed to filter
privileges depending on the exact polling parameters, and as such
moved the CAP_SYS_RESOURCE check from the proc open() callback to
psi_trigger_create(). Both the proc files as well as cgroup files go
through this during write(). This implicitly added the missing check
for privileges required for HT polling for cgroups.

When 519fabc7aa ("psi: remove 500ms min window size limitation for
triggers") followed right after to remove further restrictions on the
RT polling window, it incorrectly assumed the cgroup privilege check
was still missing and added it to the cgroup open(), mirroring what we
used to do for proc files in the past.

As a result, unprivileged poll requests that would be supported now
get rejected when opening the cgroup pressure file for writing.

Remove the cgroup open() check. psi_trigger_create() handles it.

Fixes: 519fabc7aa ("psi: remove 500ms min window size limitation for triggers")
Reported-by: Luca Boccassi <bluca@debian.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Luca Boccassi <bluca@debian.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: stable@vger.kernel.org # 6.5+
Link: https://lore.kernel.org/r/20231026164114.2488682-1-hannes@cmpxchg.org
2023-11-14 22:27:00 +01:00
Linus Torvalds
ecae0bd517 Merge tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
 "Many singleton patches against the MM code. The patch series which are
  included in this merge do the following:

   - Kemeng Shi has contributed some compation maintenance work in the
     series 'Fixes and cleanups to compaction'

   - Joel Fernandes has a patchset ('Optimize mremap during mutual
     alignment within PMD') which fixes an obscure issue with mremap()'s
     pagetable handling during a subsequent exec(), based upon an
     implementation which Linus suggested

   - More DAMON/DAMOS maintenance and feature work from SeongJae Park i
     the following patch series:

	mm/damon: misc fixups for documents, comments and its tracepoint
	mm/damon: add a tracepoint for damos apply target regions
	mm/damon: provide pseudo-moving sum based access rate
	mm/damon: implement DAMOS apply intervals
	mm/damon/core-test: Fix memory leaks in core-test
	mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval

   - In the series 'Do not try to access unaccepted memory' Adrian
     Hunter provides some fixups for the recently-added 'unaccepted
     memory' feature. To increase the feature's checking coverage. 'Plug
     a few gaps where RAM is exposed without checking if it is
     unaccepted memory'

   - In the series 'cleanups for lockless slab shrink' Qi Zheng has done
     some maintenance work which is preparation for the lockless slab
     shrinking code

   - Qi Zheng has redone the earlier (and reverted) attempt to make slab
     shrinking lockless in the series 'use refcount+RCU method to
     implement lockless slab shrink'

   - David Hildenbrand contributes some maintenance work for the rmap
     code in the series 'Anon rmap cleanups'

   - Kefeng Wang does more folio conversions and some maintenance work
     in the migration code. Series 'mm: migrate: more folio conversion
     and unification'

   - Matthew Wilcox has fixed an issue in the buffer_head code which was
     causing long stalls under some heavy memory/IO loads. Some cleanups
     were added on the way. Series 'Add and use bdev_getblk()'

   - In the series 'Use nth_page() in place of direct struct page
     manipulation' Zi Yan has fixed a potential issue with the direct
     manipulation of hugetlb page frames

   - In the series 'mm: hugetlb: Skip initialization of gigantic tail
     struct pages if freed by HVO' has improved our handling of gigantic
     pages in the hugetlb vmmemmep optimizaton code. This provides
     significant boot time improvements when significant amounts of
     gigantic pages are in use

   - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code
     rationalization and folio conversions in the hugetlb code

   - Yin Fengwei has improved mlock()'s handling of large folios in the
     series 'support large folio for mlock'

   - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has
     added statistics for memcg v1 users which are available (and
     useful) under memcg v2

   - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
     prctl so that userspace may direct the kernel to not automatically
     propagate the denial to child processes. The series is named 'MDWE
     without inheritance'

   - Kefeng Wang has provided the series 'mm: convert numa balancing
     functions to use a folio' which does what it says

   - In the series 'mm/ksm: add fork-exec support for prctl' Stefan
     Roesch makes is possible for a process to propagate KSM treatment
     across exec()

   - Huang Ying has enhanced memory tiering's calculation of memory
     distances. This is used to permit the dax/kmem driver to use 'high
     bandwidth memory' in addition to Optane Data Center Persistent
     Memory Modules (DCPMM). The series is named 'memory tiering:
     calculate abstract distance based on ACPI HMAT'

   - In the series 'Smart scanning mode for KSM' Stefan Roesch has
     optimized KSM by teaching it to retain and use some historical
     information from previous scans

   - Yosry Ahmed has fixed some inconsistencies in memcg statistics in
     the series 'mm: memcg: fix tracking of pending stats updates
     values'

   - In the series 'Implement IOCTL to get and optionally clear info
     about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap
     which permits us to atomically read-then-clear page softdirty
     state. This is mainly used by CRIU

   - Hugh Dickins contributed the series 'shmem,tmpfs: general
     maintenance', a bunch of relatively minor maintenance tweaks to
     this code

   - Matthew Wilcox has increased the use of the VMA lock over
     file-backed page faults in the series 'Handle more faults under the
     VMA lock'. Some rationalizations of the fault path became possible
     as a result

   - In the series 'mm/rmap: convert page_move_anon_rmap() to
     folio_move_anon_rmap()' David Hildenbrand has implemented some
     cleanups and folio conversions

   - In the series 'various improvements to the GUP interface' Lorenzo
     Stoakes has simplified and improved the GUP interface with an eye
     to providing groundwork for future improvements

   - Andrey Konovalov has sent along the series 'kasan: assorted fixes
     and improvements' which does those things

   - Some page allocator maintenance work from Kemeng Shi in the series
     'Two minor cleanups to break_down_buddy_pages'

   - In thes series 'New selftest for mm' Breno Leitao has developed
     another MM self test which tickles a race we had between madvise()
     and page faults

   - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups
     and an optimization to the core pagecache code

   - Nhat Pham has added memcg accounting for hugetlb memory in the
     series 'hugetlb memcg accounting'

   - Cleanups and rationalizations to the pagemap code from Lorenzo
     Stoakes, in the series 'Abstract vma_merge() and split_vma()'

   - Audra Mitchell has fixed issues in the procfs page_owner code's new
     timestamping feature which was causing some misbehaviours. In the
     series 'Fix page_owner's use of free timestamps'

   - Lorenzo Stoakes has fixed the handling of new mappings of sealed
     files in the series 'permit write-sealed memfd read-only shared
     mappings'

   - Mike Kravetz has optimized the hugetlb vmemmap optimization in the
     series 'Batch hugetlb vmemmap modification operations'

   - Some buffer_head folio conversions and cleanups from Matthew Wilcox
     in the series 'Finish the create_empty_buffers() transition'

   - As a page allocator performance optimization Huang Ying has added
     automatic tuning to the allocator's per-cpu-pages feature, in the
     series 'mm: PCP high auto-tuning'

   - Roman Gushchin has contributed the patchset 'mm: improve
     performance of accounted kernel memory allocations' which improves
     their performance by ~30% as measured by a micro-benchmark

   - folio conversions from Kefeng Wang in the series 'mm: convert page
     cpupid functions to folios'

   - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about
     kmemleak'

   - Qi Zheng has improved our handling of memoryless nodes by keeping
     them off the allocation fallback list. This is done in the series
     'handle memoryless nodes more appropriately'

   - khugepaged conversions from Vishal Moola in the series 'Some
     khugepaged folio conversions'"

[ bcachefs conflicts with the dynamically allocated shrinkers have been
  resolved as per Stephen Rothwell in

     https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/

  with help from Qi Zheng.

  The clone3 test filtering conflict was half-arsed by yours truly ]

* tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits)
  mm/damon/sysfs: update monitoring target regions for online input commit
  mm/damon/sysfs: remove requested targets when online-commit inputs
  selftests: add a sanity check for zswap
  Documentation: maple_tree: fix word spelling error
  mm/vmalloc: fix the unchecked dereference warning in vread_iter()
  zswap: export compression failure stats
  Documentation: ubsan: drop "the" from article title
  mempolicy: migration attempt to match interleave nodes
  mempolicy: mmap_lock is not needed while migrating folios
  mempolicy: alloc_pages_mpol() for NUMA policy without vma
  mm: add page_rmappable_folio() wrapper
  mempolicy: remove confusing MPOL_MF_LAZY dead code
  mempolicy: mpol_shared_policy_init() without pseudo-vma
  mempolicy trivia: use pgoff_t in shared mempolicy tree
  mempolicy trivia: slightly more consistent naming
  mempolicy trivia: delete those ancient pr_debug()s
  mempolicy: fix migrate_pages(2) syscall return nr_failed
  kernfs: drop shared NUMA mempolicy hooks
  hugetlbfs: drop shared NUMA mempolicy pretence
  mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()
  ...
2023-11-02 19:38:47 -10:00
Linus Torvalds
89ed67ef12 Merge tag 'net-next-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Support usec resolution of TCP timestamps, enabled selectively by a
     route attribute.

   - Defer regular TCP ACK while processing socket backlog, try to send
     a cumulative ACK at the end. Increase single TCP flow performance
     on a 200Gbit NIC by 20% (100Gbit -> 120Gbit).

   - The Fair Queuing (FQ) packet scheduler:
       - add built-in 3 band prio / WRR scheduling
       - support bypass if the qdisc is mostly idle (5% speed up for TCP RR)
       - improve inactive flow reporting
       - optimize the layout of structures for better cache locality

   - Support TCP Authentication Option (RFC 5925, TCP-AO), a more modern
     replacement for the old MD5 option.

   - Add more retransmission timeout (RTO) related statistics to
     TCP_INFO.

   - Support sending fragmented skbs over vsock sockets.

   - Make sure we send SIGPIPE for vsock sockets if socket was
     shutdown().

   - Add sysctl for ignoring lower limit on lifetime in Router
     Advertisement PIO, based on an in-progress IETF draft.

   - Add sysctl to control activation of TCP ping-pong mode.

   - Add sysctl to make connection timeout in MPTCP configurable.

   - Support rcvlowat and notsent_lowat on MPTCP sockets, to help apps
     limit the number of wakeups.

   - Support netlink GET for MDB (multicast forwarding), allowing user
     space to request a single MDB entry instead of dumping the entire
     table.

   - Support selective FDB flushing in the VXLAN tunnel driver.

   - Allow limiting learned FDB entries in bridges, prevent OOM attacks.

   - Allow controlling via configfs netconsole targets which were
     created via the kernel cmdline at boot, rather than via configfs at
     runtime.

   - Support multiple PTP timestamp event queue readers with different
     filters.

   - MCTP over I3C.

  BPF:

   - Add new veth-like netdevice where BPF program defines the logic of
     the xmit routine. It can operate in L3 and L2 mode.

   - Support exceptions - allow asserting conditions which should never
     be true but are hard for the verifier to infer. With some extra
     flexibility around handling of the exit / failure:

          https://lwn.net/Articles/938435/

   - Add support for local per-cpu kptr, allow allocating and storing
     per-cpu objects in maps. Access to those objects operates on the
     value for the current CPU.

     This allows to deprecate local one-off implementations of per-CPU
     storage like BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE maps.

   - Extend cgroup BPF sockaddr hooks for UNIX sockets. The use case is
     for systemd to re-implement the LogNamespace feature which allows
     running multiple instances of systemd-journald to process the logs
     of different services.

   - Enable open-coded task_vma iteration, after maple tree conversion
     made it hard to directly walk VMAs in tracing programs.

   - Add open-coded task, css_task and css iterator support. One of the
     use cases is customizable OOM victim selection via BPF.

   - Allow source address selection with bpf_*_fib_lookup().

   - Add ability to pin BPF timer to the current CPU.

   - Prevent creation of infinite loops by combining tail calls and
     fentry/fexit programs.

   - Add missed stats for kprobes to retrieve the number of missed
     kprobe executions and subsequent executions of BPF programs.

   - Inherit system settings for CPU security mitigations.

   - Add BPF v4 CPU instruction support for arm32 and s390x.

  Changes to common code:

   - overflow: add DEFINE_FLEX() for on-stack definition of structs with
     flexible array members.

   - Process doc update with more guidance for reviewers.

  Driver API:

   - Simplify locking in WiFi (cfg80211 and mac80211 layers), use wiphy
     mutex in most places and remove a lot of smaller locks.

   - Create a common DPLL configuration API. Allow configuring and
     querying state of PLL circuits used for clock syntonization, in
     network time distribution.

   - Unify fragmented and full page allocation APIs in page pool code.
     Let drivers be ignorant of PAGE_SIZE.

   - Rework PHY state machine to avoid races with calls to phy_stop().

   - Notify DSA drivers of MAC address changes on user ports, improve
     correctness of offloads which depend on matching port MAC
     addresses.

   - Allow antenna control on injected WiFi frames.

   - Reduce the number of variants of napi_schedule().

   - Simplify error handling when composing devlink health messages.

  Misc:

   - A lot of KCSAN data race "fixes", from Eric.

   - A lot of __counted_by() annotations, from Kees.

   - A lot of strncpy -> strscpy and printf format fixes.

   - Replace master/slave terminology with conduit/user in DSA drivers.

   - Handful of KUnit tests for netdev and WiFi core.

  Removed:

   - AppleTalk COPS.

   - AppleTalk ipddp.

   - TI AR7 CPMAC Ethernet driver.

  Drivers:

   - Ethernet high-speed NICs:
      - Intel (100G, ice, idpf):
         - add a driver for the Intel E2000 IPUs
         - make CRC/FCS stripping configurable
         - cross-timestamping for E823 devices
         - basic support for E830 devices
         - use aux-bus for managing client drivers
         - i40e: report firmware versions via devlink
      - nVidia/Mellanox:
         - support 4-port NICs
         - increase max number of channels to 256
         - optimize / parallelize SF creation flow
      - Broadcom (bnxt):
         - enhance NIC temperature reporting
         - support PAM4 speeds and lane configuration
      - Marvell OcteonTX2:
         - PTP pulse-per-second output support
         - enable hardware timestamping for VFs
      - Solarflare/AMD:
         - conntrack NAT offload and offload for tunnels
      - Wangxun (ngbe/txgbe):
         - expose HW statistics
      - Pensando/AMD:
         - support PCI level reset
         - narrow down the condition under which skbs are linearized
      - Netronome/Corigine (nfp):
         - support CHACHA20-POLY1305 crypto in IPsec offload

   - Ethernet NICs embedded, slower, virtual:
      - Synopsys (stmmac):
         - add Loongson-1 SoC support
         - enable use of HW queues with no offload capabilities
         - enable PPS input support on all 5 channels
         - increase TX coalesce timer to 5ms
      - RealTek USB (r8152): improve efficiency of Rx by using GRO frags
      - xen: support SW packet timestamping
      - add drivers for implementations based on TI's PRUSS (AM64x EVM)

   - nVidia/Mellanox Ethernet datacenter switches:
      - avoid poor HW resource use on Spectrum-4 by better block
        selection for IPv6 multicast forwarding and ordering of blocks
        in ACL region

   - Ethernet embedded switches:
      - Microchip:
         - support configuring the drive strength for EMI compliance
         - ksz9477: partial ACL support
         - ksz9477: HSR offload
         - ksz9477: Wake on LAN
      - Realtek:
         - rtl8366rb: respect device tree config of the CPU port

   - Ethernet PHYs:
      - support Broadcom BCM5221 PHYs
      - TI dp83867: support hardware LED blinking

   - CAN:
      - add support for Linux-PHY based CAN transceivers
      - at91_can: clean up and use rx-offload helpers

   - WiFi:
      - MediaTek (mt76):
         - new sub-driver for mt7925 USB/PCIe devices
         - HW wireless <> Ethernet bridging in MT7988 chips
         - mt7603/mt7628 stability improvements
      - Qualcomm (ath12k):
         - WCN7850:
            - enable 320 MHz channels in 6 GHz band
            - hardware rfkill support
            - enable IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS to
              make scan faster
            - read board data variant name from SMBIOS
        - QCN9274: mesh support
      - RealTek (rtw89):
         - TDMA-based multi-channel concurrency (MCC)
      - Silicon Labs (wfx):
         - Remain-On-Channel (ROC) support

   - Bluetooth:
      - ISO: many improvements for broadcast support
      - mark BCM4378/BCM4387 as BROKEN_LE_CODED
      - add support for QCA2066
      - btmtksdio: enable Bluetooth wakeup from suspend"

* tag 'net-next-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1816 commits)
  net: pcs: xpcs: Add 2500BASE-X case in get state for XPCS drivers
  net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos()
  net: mana: Use xdp_set_features_flag instead of direct assignment
  vxlan: Cleanup IFLA_VXLAN_PORT_RANGE entry in vxlan_get_size()
  iavf: delete the iavf client interface
  iavf: add a common function for undoing the interrupt scheme
  iavf: use unregister_netdev
  iavf: rely on netdev's own registered state
  iavf: fix the waiting time for initial reset
  iavf: in iavf_down, don't queue watchdog_task if comms failed
  iavf: simplify mutex_trylock+sleep loops
  iavf: fix comments about old bit locks
  doc/netlink: Update schema to support cmd-cnt-name and cmd-max-name
  tools: ynl: introduce option to process unknown attributes or types
  ipvlan: properly track tx_errors
  netdevsim: Block until all devices are released
  nfp: using napi_build_skb() to replace build_skb()
  net: dsa: microchip: ksz9477: Fix spelling mistake "Enery" -> "Energy"
  net: dsa: microchip: Ensure Stable PME Pin State for Wake-on-LAN
  net: dsa: microchip: Refactor switch shutdown routine for WoL preparation
  ...
2023-10-31 05:10:11 -10:00
Chuyi Zhou
6da8830681 cgroup: Prepare for using css_task_iter_*() in BPF
This patch makes some preparations for using css_task_iter_*() in BPF
Program.

1. Flags CSS_TASK_ITER_* are #define-s and it's not easy for bpf prog to
use them. Convert them to enum so bpf prog can take them from vmlinux.h.

2. In the next patch we will add css_task_iter_*() in common kfuncs which
is not safe. Since css_task_iter_*() does spin_unlock_irq() which might
screw up irq flags depending on the context where bpf prog is running.
So we should use irqsave/irqrestore here and the switching is harmless.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-2-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-10-19 17:02:46 -07:00
Nhat Pham
8cba9576df hugetlb: memcg: account hugetlb-backed memory in memory controller
Currently, hugetlb memory usage is not acounted for in the memory
controller, which could lead to memory overprotection for cgroups with
hugetlb-backed memory.  This has been observed in our production system.

For instance, here is one of our usecases: suppose there are two 32G
containers.  The machine is booted with hugetlb_cma=6G, and each container
may or may not use up to 3 gigantic page, depending on the workload within
it.  The rest is anon, cache, slab, etc.  We can set the hugetlb cgroup
limit of each cgroup to 3G to enforce hugetlb fairness.  But it is very
difficult to configure memory.max to keep overall consumption, including
anon, cache, slab etc.  fair.

What we have had to resort to is to constantly poll hugetlb usage and
readjust memory.max.  Similar procedure is done to other memory limits
(memory.low for e.g).  However, this is rather cumbersome and buggy. 
Furthermore, when there is a delay in memory limits correction, (for e.g
when hugetlb usage changes within consecutive runs of the userspace
agent), the system could be in an over/underprotected state.

This patch rectifies this issue by charging the memcg when the hugetlb
folio is utilized, and uncharging when the folio is freed (analogous to
the hugetlb controller).  Note that we do not charge when the folio is
allocated to the hugetlb pool, because at this point it is not owned by
any memcg.

Some caveats to consider:
  * This feature is only available on cgroup v2.
  * There is no hugetlb pool management involved in the memory
    controller. As stated above, hugetlb folios are only charged towards
    the memory controller when it is used. Host overcommit management
    has to consider it when configuring hard limits.
  * Failure to charge towards the memcg results in SIGBUS. This could
    happen even if the hugetlb pool still has pages (but the cgroup
    limit is hit and reclaim attempt fails).
  * When this feature is enabled, hugetlb pages contribute to memory
    reclaim protection. low, min limits tuning must take into account
    hugetlb memory.
  * Hugetlb pages utilized while this option is not selected will not
    be tracked by the memory controller (even if cgroup v2 is remounted
    later on).

Link: https://lkml.kernel.org/r/20231006184629.155543-4-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:17 -07:00
Kamalesh Babulal
27a6c5c50c cgroup: use legacy_name for cgroup v1 disable info
cgroup v1 or v2 or both controller names can be passed as arguments to
the 'cgroup_no_v1' kernel parameter, though most of the controller's
names are the same for both cgroup versions. This can be confusing when
both versions are used interchangeably, i.e., passing cgroup_no_v1=io

$ sudo dmesg |grep cgroup
...
cgroup: Disabling io control group subsystem in v1 mounts
cgroup: Disabled controller 'blkio'

Make it consistent across the pr_info()'s, by using ss->legacy_name, as
the subsystem name, while printing the cgroup v1 controller disabling
information in cgroup_init().

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-10-09 06:46:56 -10:00
Luiz Capitulino
9b81d3a5be cgroup: add cgroup_favordynmods= command-line option
We have a need of using favordynmods with cgroup v1, which doesn't support
changing mount flags during remount. Enabling CONFIG_CGROUP_FAVOR_DYNMODS at
build-time is not an option because we want to be able to selectively
enable it for certain systems.

This commit addresses this by introducing the cgroup_favordynmods=
command-line option. This option works for both cgroup v1 and v2 and also
allows for disabling favorynmods when the kernel built with
CONFIG_CGROUP_FAVOR_DYNMODS=y.

Also, note that when cgroup_favordynmods=true favordynmods is never
disabled in cgroup_destroy_root().

Signed-off-by: Luiz Capitulino <luizcap@amazon.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-10-04 08:47:55 -10:00
Kamalesh Babulal
d24f05987c cgroup: Avoid extra dereference in css_populate_dir()
Use css directly instead of dereferencing it from &cgroup->self, while
adding the cgroup v2 cft base and psi files in css_populate_dir(). Both
points to the same css, when css->ss is NULL, this avoids extra deferences
and makes code consistent in usage across the function.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-18 08:58:27 -10:00
Kamalesh Babulal
fd55c0adb4 cgroup: Check for ret during cgroup1_base_files cft addition
There is no check for possible failure while populating
cgroup1_base_files cft in css_populate_dir(), like its cgroup v2 counter
parts cgroup_{base,psi}_files.  In case of failure, the cgroup might not
be set up right.  Add ret value check to return on failure.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-18 08:57:22 -10:00
Linus Torvalds
76be05d4fd cgroup: fix build when CGROUP_SCHED is not enabled
Sudip Mukherjee reports that the mips sb1250_swarm_defconfig build fails
with the current kernel.  It isn't actually MIPS-specific, it's just
that that defconfig does not have CGROUP_SCHED enabled like most configs
do, and as such shows this error:

  kernel/cgroup/cgroup.c: In function 'cgroup_local_stat_show':
  kernel/cgroup/cgroup.c:3699:15: error: implicit declaration of function 'cgroup_tryget_css'; did you mean 'cgroup_tryget'? [-Werror=implicit-function-declaration]
   3699 |         css = cgroup_tryget_css(cgrp, ss);
        |               ^~~~~~~~~~~~~~~~~
        |               cgroup_tryget
  kernel/cgroup/cgroup.c:3699:13: warning: assignment to 'struct cgroup_subsys_state *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   3699 |         css = cgroup_tryget_css(cgrp, ss);
        |             ^

because cgroup_tryget_css() only exists when CGROUP_SCHED is enabled,
and the cgroup_local_stat_show() function should similarly be guarded by
that config option.

Move things around a bit to fix this all.

Fixes: d1d4ff5d11 ("cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED")
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-09-02 08:27:17 -07:00
Linus Torvalds
7716f383a5 Merge tag 'cgroup-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - Per-cpu cpu usage stats are now tracked

   This currently isn't printed out in the cgroupfs interface and can
   only be accessed through e.g. BPF. Should decide on a not-too-ugly
   way to show per-cpu stats in cgroupfs

 - cpuset received some cleanups and prepatory patches for the pending
   cpus.exclusive patchset which will allow cpuset partitions to be
   created below non-partition parents, which should ease the management
   of partition cpusets

 - A lot of code and documentation cleanup patches

 - tools/testing/selftests/cgroup/test_cpuset.c added

* tag 'cgroup-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (32 commits)
  cgroup: Avoid -Wstringop-overflow warnings
  cgroup:namespace: Remove unused cgroup_namespaces_init()
  cgroup/rstat: Record the cumulative per-cpu time of cgroup and its descendants
  cgroup: clean up if condition in cgroup_pidlist_start()
  cgroup: fix obsolete function name in cgroup_destroy_locked()
  Documentation: cgroup-v2.rst: Correct number of stats entries
  cgroup: fix obsolete function name above css_free_rwork_fn()
  cgroup/cpuset: fix kernel-doc
  cgroup: clean up printk()
  cgroup: fix obsolete comment above cgroup_create()
  docs: cgroup-v1: fix typo
  docs: cgroup-v1: correct the term of Page Cache organization in inode
  cgroup/misc: Store atomic64_t reads to u64
  cgroup/misc: Change counters to be explicit 64bit types
  cgroup/misc: update struct members descriptions
  cgroup: remove cgrp->kn check in css_populate_dir()
  cgroup: fix obsolete function name
  cgroup: use cached local variable parent in for loop
  cgroup: remove obsolete comment above struct cgroupstats
  cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED
  ...
2023-09-01 15:58:21 -07:00
Gustavo A. R. Silva
78d44b824e cgroup: Avoid -Wstringop-overflow warnings
Change the notation from pointer-to-array to pointer-to-pointer.
With this, we avoid the compiler complaining about trying
to access a region of size zero as an argument during function
calls.

This is a workaround to prevent the compiler complaining about
accessing an array of size zero when evaluating the arguments
of a couple of function calls. See below:

kernel/cgroup/cgroup.c: In function 'find_css_set':
kernel/cgroup/cgroup.c:1206:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
 1206 |         cset = find_existing_css_set(old_cset, cgrp, template);
      |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/cgroup/cgroup.c:1206:16: note: referencing argument 3 of type 'struct cgroup_subsys_state *[0]'
kernel/cgroup/cgroup.c:1071:24: note: in a call to function 'find_existing_css_set'
 1071 | static struct css_set *find_existing_css_set(struct css_set *old_cset,
      |                        ^~~~~~~~~~~~~~~~~~~~~

With the change to pointer-to-pointer, the functions are not prevented
from being executed, and they will do what they have to do when
CGROUP_SUBSYS_COUNT == 0.

Address the following -Wstringop-overflow warnings seen when
built with ARM architecture and aspeed_g4_defconfig configuration
(notice that under this configuration CGROUP_SUBSYS_COUNT == 0):

kernel/cgroup/cgroup.c:1208:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
kernel/cgroup/cgroup.c:1258:15: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
kernel/cgroup/cgroup.c:6089:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
kernel/cgroup/cgroup.c:6153:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]

This results in no differences in binary output.

Link: https://github.com/KSPP/linux/issues/316
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-08-17 11:55:05 -10:00
Miaohe Lin
7f828eacc4 cgroup: fix obsolete function name in cgroup_destroy_locked()
Since commit e76ecaeef6 ("cgroup: use cgroup_kn_lock_live() in other
cgroup kernfs methods"), cgroup_kn_lock_live() is used in cgroup kernfs
methods. Update corresponding comment.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-08-03 14:13:33 -10:00
Miaohe Lin
a2c15fece4 cgroup: fix obsolete function name above css_free_rwork_fn()
Since commit 8f36aaec9c ("cgroup: Use rcu_work instead of explicit rcu
and work item"), css_free_work_fn has been renamed to css_free_rwork_fn.
Update corresponding comment.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-08-02 09:37:59 -10:00
Kamalesh Babulal
55a5956a55 cgroup: clean up printk()
Convert the only printk() to use pr_*() helper. No functional change.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-08-02 09:36:24 -10:00
Miaohe Lin
a3fdeeb3f1 cgroup: fix obsolete comment above cgroup_create()
Since commit 743210386c ("cgroup: use cgrp->kn->id as the cgroup ID"),
cgrp is associated with its kernfs_node. Update corresponding comment.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-21 09:54:48 -10:00
Ingo Molnar
752182b24b Merge tag 'v6.5-rc2' into sched/core, to pick up fixes
Sync with upstream fixes before applying EEVDF.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2023-07-19 09:43:25 +02:00
Kamalesh Babulal
c25ff4b911 cgroup: remove cgrp->kn check in css_populate_dir()
cgroup_create() creates cgrp and assigns the kernfs_node to cgrp->kn,
then cgroup_mkdir() populates base and csses cft file by calling
css_populate_dir() and cgroup_apply_control_enable() with a valid
cgrp->kn. Check for NULL cgrp->kn, will always be false, remove it.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-17 08:44:56 -10:00
Miaohe Lin
6f71780e7f cgroup: fix obsolete function name
cgroup_taskset_migrate() has been renamed to cgroup_migrate_execute() since
commit e595cd7069 ("cgroup: track migration context in cgroup_mgctx").
Update the corresponding comment.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-17 08:38:58 -10:00
Miaohe Lin
fcbb485d9f cgroup: use cached local variable parent in for loop
Use local variable parent to initialize iter tcgrp in for loop so the size
of cgroup.o can be reduced by 64 bytes. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-17 08:34:41 -10:00
Josh Don
677ea015f2 sched: add throttled time stat for throttled children
We currently export the total throttled time for cgroups that are given
a bandwidth limit. This patch extends this accounting to also account
the total time that each children cgroup has been throttled.

This is useful to understand the degree to which children have been
affected by the throttling control. Children which are not runnable
during the entire throttled period, for example, will not show any
self-throttling time during this period.

Expose this in a new interface, 'cpu.stat.local', which is similar to
how non-hierarchical events are accounted in 'memory.events.local'.

Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230620183247.737942-2-joshdon@google.com
2023-07-13 15:21:49 +02:00
Miaohe Lin
d1d4ff5d11 cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED
Put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED to fix the warning
of 'cgroup_tryget_css' defined but not used [-Wunused-function] when
CONFIG_CGROUP_SCHED is disabled.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-11 11:46:00 -10:00
Miaohe Lin
868f87b375 cgroup: fix obsolete comment above for_each_css()
cgroup_tree_mutex is removed since commit 8353da1f91 ("cgroup: remove
cgroup_tree_mutex"), update corresponding comment.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-10 10:47:25 -10:00
Miaohe Lin
1299eb2b0a cgroup: minor cleanup for cgroup_extra_stat_show()
Make it under CONFIG_CGROUP_SCHED to rid of __maybe_unused annotation.
And further fetch cgrp inside cgroup_extra_stat_show() directly to rid
of __maybe_unused annotation of cgrp. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-10 10:23:41 -10:00
Miaohe Lin
2246ca53d7 cgroup: remove unneeded return value of cgroup_rm_cftypes_locked()
The return value of cgroup_rm_cftypes_locked() is always 0. So remove
it to simplify the code. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-07-10 09:39:22 -10:00