<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/mm/page_alloc.c, branch v6.8.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations</title>
<updated>2024-03-05T00:40:32+00:00</updated>
<author>
<name>Vlastimil Babka</name>
<email>vbabka@suse.cz</email>
</author>
<published>2024-02-21T11:43:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=803de9000f334b771afacb6ff3e78622916668b0'/>
<id>803de9000f334b771afacb6ff3e78622916668b0</id>
<content type='text'>
Sven reports an infinite loop in __alloc_pages_slowpath() for costly order
__GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO.  Such combination
can happen in a suspend/resume context where a GFP_KERNEL allocation can
have __GFP_IO masked out via gfp_allowed_mask.

Quoting Sven:

1. try to do a "costly" allocation (order &gt; PAGE_ALLOC_COSTLY_ORDER)
   with __GFP_RETRY_MAYFAIL set.

2. page alloc's __alloc_pages_slowpath tries to get a page from the
   freelist. This fails because there is nothing free of that costly
   order.

3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim,
   which bails out because a zone is ready to be compacted; it pretends
   to have made a single page of progress.

4. page alloc tries to compact, but this always bails out early because
   __GFP_IO is not set (it's not passed by the snd allocator, and even
   if it were, we are suspending so the __GFP_IO flag would be cleared
   anyway).

5. page alloc believes reclaim progress was made (because of the
   pretense in item 3) and so it checks whether it should retry
   compaction. The compaction retry logic thinks it should try again,
   because:
    a) reclaim is needed because of the early bail-out in item 4
    b) a zonelist is suitable for compaction

6. goto 2. indefinite stall.

(end quote)

The immediate root cause is confusing the COMPACT_SKIPPED returned from
__alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be
indicating a lack of order-0 pages, and in step 5 evaluating that in
should_compact_retry() as a reason to retry, before incrementing and
limiting the number of retries.  There are however other places that
wrongly assume that compaction can happen while we lack __GFP_IO.

To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO
evaluation and switch the open-coded test in try_to_compact_pages() to use
it.

Also use the new helper in:
- compaction_ready(), which will make reclaim not bail out in step 3, so
  there's at least one attempt to actually reclaim, even if chances are
  small for a costly order
- in_reclaim_compaction() which will make should_continue_reclaim()
  return false and we don't over-reclaim unnecessarily
- in __alloc_pages_slowpath() to set a local variable can_compact,
  which is then used to avoid retrying reclaim/compaction for costly
  allocations (step 5) if we can't compact and also to skip the early
  compaction attempt that we do in some cases

Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz
Fixes: 3250845d0526 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"")
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Reported-by: Sven van Ashbrook &lt;svenva@chromium.org&gt;
Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBzPUVOZF%2Bg@mail.gmail.com/
Tested-by: Karthikeyan Ramasubramanian &lt;kramasub@chromium.org&gt;
Cc: Brian Geffon &lt;bgeffon@google.com&gt;
Cc: Curtis Malainey &lt;cujomalainey@chromium.org&gt;
Cc: Jaroslav Kysela &lt;perex@perex.cz&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Takashi Iwai &lt;tiwai@suse.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sven reports an infinite loop in __alloc_pages_slowpath() for costly order
__GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO.  Such combination
can happen in a suspend/resume context where a GFP_KERNEL allocation can
have __GFP_IO masked out via gfp_allowed_mask.

Quoting Sven:

1. try to do a "costly" allocation (order &gt; PAGE_ALLOC_COSTLY_ORDER)
   with __GFP_RETRY_MAYFAIL set.

2. page alloc's __alloc_pages_slowpath tries to get a page from the
   freelist. This fails because there is nothing free of that costly
   order.

3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim,
   which bails out because a zone is ready to be compacted; it pretends
   to have made a single page of progress.

4. page alloc tries to compact, but this always bails out early because
   __GFP_IO is not set (it's not passed by the snd allocator, and even
   if it were, we are suspending so the __GFP_IO flag would be cleared
   anyway).

5. page alloc believes reclaim progress was made (because of the
   pretense in item 3) and so it checks whether it should retry
   compaction. The compaction retry logic thinks it should try again,
   because:
    a) reclaim is needed because of the early bail-out in item 4
    b) a zonelist is suitable for compaction

6. goto 2. indefinite stall.

(end quote)

The immediate root cause is confusing the COMPACT_SKIPPED returned from
__alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be
indicating a lack of order-0 pages, and in step 5 evaluating that in
should_compact_retry() as a reason to retry, before incrementing and
limiting the number of retries.  There are however other places that
wrongly assume that compaction can happen while we lack __GFP_IO.

To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO
evaluation and switch the open-coded test in try_to_compact_pages() to use
it.

Also use the new helper in:
- compaction_ready(), which will make reclaim not bail out in step 3, so
  there's at least one attempt to actually reclaim, even if chances are
  small for a costly order
- in_reclaim_compaction() which will make should_continue_reclaim()
  return false and we don't over-reclaim unnecessarily
- in __alloc_pages_slowpath() to set a local variable can_compact,
  which is then used to avoid retrying reclaim/compaction for costly
  allocations (step 5) if we can't compact and also to skip the early
  compaction attempt that we do in some cases

Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz
Fixes: 3250845d0526 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"")
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Reported-by: Sven van Ashbrook &lt;svenva@chromium.org&gt;
Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBzPUVOZF%2Bg@mail.gmail.com/
Tested-by: Karthikeyan Ramasubramanian &lt;kramasub@chromium.org&gt;
Cc: Brian Geffon &lt;bgeffon@google.com&gt;
Cc: Curtis Malainey &lt;cujomalainey@chromium.org&gt;
Cc: Jaroslav Kysela &lt;perex@perex.cz&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Takashi Iwai &lt;tiwai@suse.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2024-01-11T18:07:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-01-11T18:07:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3e7aeb78ab01c2c2f0e1f784e5ddec88fcd3d106'/>
<id>3e7aeb78ab01c2c2f0e1f784e5ddec88fcd3d106</id>
<content type='text'>
Pull networking updates from Paolo Abeni:
 "The most interesting thing is probably the networking structs
  reorganization and a significant amount of changes is around
  self-tests.

  Core &amp; protocols:

   - Analyze and reorganize core networking structs (socks, netdev,
     netns, mibs) to optimize cacheline consumption and set up build
     time warnings to safeguard against future header changes

     This improves TCP performances with many concurrent connections up
     to 40%

   - Add page-pool netlink-based introspection, exposing the memory
     usage and recycling stats. This helps indentify bad PP users and
     possible leaks

   - Refine TCP/DCCP source port selection to no longer favor even
     source port at connect() time when IP_LOCAL_PORT_RANGE is set. This
     lowers the time taken by connect() for hosts having many active
     connections to the same destination

   - Refactor the TCP bind conflict code, shrinking related socket
     structs

   - Refactor TCP SYN-Cookie handling, as a preparation step to allow
     arbitrary SYN-Cookie processing via eBPF

   - Tune optmem_max for 0-copy usage, increasing the default value to
     128KB and namespecifying it

   - Allow coalescing for cloned skbs coming from page pools, improving
     RX performances with some common configurations

   - Reduce extension header parsing overhead at GRO time

   - Add bridge MDB bulk deletion support, allowing user-space to
     request the deletion of matching entries

   - Reorder nftables struct members, to keep data accessed by the
     datapath first

   - Introduce TC block ports tracking and use. This allows supporting
     multicast-like behavior at the TC layer

   - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
     classifiers (RSVP and tcindex)

   - More data-race annotations

   - Extend the diag interface to dump TCP bound-only sockets

   - Conditional notification of events for TC qdisc class and actions

   - Support for WPAN dynamic associations with nearby devices, to form
     a sub-network using a specific PAN ID

   - Implement SMCv2.1 virtual ISM device support

   - Add support for Batman-avd mulicast packet type

  BPF:

   - Tons of verifier improvements:
       - BPF register bounds logic and range support along with a large
         test suite
       - log improvements
       - complete precision tracking support for register spills
       - track aligned STACK_ZERO cases as imprecise spilled registers.
         This improves the verifier "instructions processed" metric from
         single digit to 50-60% for some programs
       - support for user's global BPF subprogram arguments with few
         commonly requested annotations for a better developer
         experience
       - support tracking of BPF_JNE which helps cases when the compiler
         transforms (unsigned) "a &gt; 0" into "if a == 0 goto xxx" and the
         like
       - several fixes

   - Add initial TX metadata implementation for AF_XDP with support in
     mlx5 and stmmac drivers. Two types of offloads are supported right
     now, that is, TX timestamp and TX checksum offload

   - Fix kCFI bugs in BPF all forms of indirect calls from BPF into
     kernel and from kernel into BPF work with CFI enabled. This allows
     BPF to work with CONFIG_FINEIBT=y

   - Change BPF verifier logic to validate global subprograms lazily
     instead of unconditionally before the main program, so they can be
     guarded using BPF CO-RE techniques

   - Support uid/gid options when mounting bpffs

   - Add a new kfunc which acquires the associated cgroup of a task
     within a specific cgroup v1 hierarchy where the latter is
     identified by its id

   - Extend verifier to allow bpf_refcount_acquire() of a map value
     field obtained via direct load which is a use-case needed in
     sched_ext

   - Add BPF link_info support for uprobe multi link along with bpftool
     integration for the latter

   - Support for VLAN tag in XDP hints

   - Remove deprecated bpfilter kernel leftovers given the project is
     developed in user-space (https://github.com/facebook/bpfilter)

  Misc:

   - Support for parellel TC self-tests execution

   - Increase MPTCP self-tests coverage

   - Updated the bridge documentation, including several so-far
     undocumented features

   - Convert all the net self-tests to run in unique netns, to avoid
     random failures due to conflict and allow concurrent runs

   - Add TCP-AO self-tests

   - Add kunit tests for both cfg80211 and mac80211

   - Autogenerate Netlink families documentation from YAML spec

   - Add yml-gen support for fixed headers and recursive nests, the tool
     can now generate user-space code for all genetlink families for
     which we have specs

   - A bunch of additional module descriptions fixes

   - Catch incorrect freeing of pages belonging to a page pool

  Driver API:

   - Rust abstractions for network PHY drivers; do not cover yet the
     full C API, but already allow implementing functional PHY drivers
     in rust

   - Introduce queue and NAPI support in the netdev Netlink interface,
     allowing complete access to the device &lt;&gt; NAPIs &lt;&gt; queues
     relationship

   - Introduce notifications filtering for devlink to allow control
     application scale to thousands of instances

   - Improve PHY validation, requesting rate matching information for
     each ethtool link mode supported by both the PHY and host

   - Add support for ethtool symmetric-xor RSS hash

   - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
     platform

   - Expose pin fractional frequency offset value over new DPLL generic
     netlink attribute

   - Convert older drivers to platform remove callback returning void

   - Add support for PHY package MMD read/write

  New hardware / drivers:

   - Ethernet:
       - Octeon CN10K devices
       - Broadcom 5760X P7
       - Qualcomm SM8550 SoC
       - Texas Instrument DP83TG720S PHY

   - Bluetooth:
       - IMC Networks Bluetooth radio

  Removed:

   - WiFi:
       - libertas 16-bit PCMCIA support
       - Atmel at76c50x drivers
       - HostAP ISA/PCMCIA style 802.11b driver
       - zd1201 802.11b USB dongles
       - Orinoco ISA/PCMCIA 802.11b driver
       - Aviator/Raytheon driver
       - Planet WL3501 driver
       - RNDIS USB 802.11b driver

  Driver updates:

   - Ethernet high-speed NICs:
       - Intel (100G, ice, idpf):
          - allow one by one port representors creation and removal
          - add temperature and clock information reporting
          - add get/set for ethtool's header split ringparam
          - add again FW logging
          - adds support switchdev hardware packet mirroring
          - iavf: implement symmetric-xor RSS hash
          - igc: add support for concurrent physical and free-running
            timers
          - i40e: increase the allowable descriptors
       - nVidia/Mellanox:
          - Preparation for Socket-Direct multi-dev netdev. That will
            allow in future releases combining multiple PFs devices
            attached to different NUMA nodes under the same netdev
       - Broadcom (bnxt):
          - TX completion handling improvements
          - add basic ntuple filter support
          - reduce MSIX vectors usage for MQPRIO offload
          - add VXLAN support, USO offload and TX coalesce completion
            for P7
       - Marvell Octeon EP:
          - xmit-more support
          - add PF-VF mailbox support and use it for FW notifications
            for VFs
       - Wangxun (ngbe/txgbe):
          - implement ethtool functions to operate pause param, ring
            param, coalesce channel number and msglevel
       - Netronome/Corigine (nfp):
          - add flow-steering support
          - support UDP segmentation offload

   - Ethernet NICs embedded, slower, virtual:
       - Xilinx AXI: remove duplicate DMA code adopting the dma engine
         driver
       - stmmac: add support for HW-accelerated VLAN stripping
       - TI AM654x sw: add mqprio, frame preemption &amp; coalescing
       - gve: add support for non-4k page sizes.
       - virtio-net: support dynamic coalescing moderation

   - nVidia/Mellanox Ethernet datacenter switches:
       - allow firmware upgrade without a reboot
       - more flexible support for bridge flooding via the compressed
         FID flooding mode

   - Ethernet embedded switches:
       - Microchip:
          - fine-tune flow control and speed configurations in KSZ8xxx
          - KSZ88X3: enable setting rmii reference
       - Renesas:
          - add jumbo frames support
       - Marvell:
          - 88E6xxx: add "eth-mac" and "rmon" stats support

   - Ethernet PHYs:
       - aquantia: add firmware load support
       - at803x: refactor the driver to simplify adding support for more
         chip variants
       - NXP C45 TJA11xx: Add MACsec offload support

   - Wifi:
       - MediaTek (mt76):
          - NVMEM EEPROM improvements
          - mt7996 Extremely High Throughput (EHT) improvements
          - mt7996 Wireless Ethernet Dispatcher (WED) support
          - mt7996 36-bit DMA support
       - Qualcomm (ath12k):
          - support for a single MSI vector
          - WCN7850: support AP mode
       - Intel (iwlwifi):
          - new debugfs file fw_dbg_clear
          - allow concurrent P2P operation on DFS channels

   - Bluetooth:
       - QCA2066: support HFP offload
       - ISO: more broadcast-related improvements
       - NXP: better recovery in case receiver/transmitter get out of sync"

* tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1714 commits)
  lan78xx: remove redundant statement in lan78xx_get_eee
  lan743x: remove redundant statement in lan743x_ethtool_get_eee
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_rx_flow_steer()
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_srxclsrldel()
  bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()
  tcp: Revert no longer abort SYN_SENT when receiving some ICMP
  Revert "mlx5 updates 2023-12-20"
  Revert "net: stmmac: Enable Per DMA Channel interrupt"
  ipvlan: Remove usage of the deprecated ida_simple_xx() API
  ipvlan: Fix a typo in a comment
  net/sched: Remove ipt action tests
  net: stmmac: Use interrupt mode INTM=1 for per channel irq
  net: stmmac: Add support for TX/RX channel interrupt
  net: stmmac: Make MSI interrupt routine generic
  dt-bindings: net: snps,dwmac: per channel irq
  net: phy: at803x: make read_status more generic
  net: phy: at803x: add support for cdt cross short test for qca808x
  net: phy: at803x: refactor qca808x cable test get status function
  net: phy: at803x: generalize cdt fault length function
  net: ethernet: cortina: Drop TSO support
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking updates from Paolo Abeni:
 "The most interesting thing is probably the networking structs
  reorganization and a significant amount of changes is around
  self-tests.

  Core &amp; protocols:

   - Analyze and reorganize core networking structs (socks, netdev,
     netns, mibs) to optimize cacheline consumption and set up build
     time warnings to safeguard against future header changes

     This improves TCP performances with many concurrent connections up
     to 40%

   - Add page-pool netlink-based introspection, exposing the memory
     usage and recycling stats. This helps indentify bad PP users and
     possible leaks

   - Refine TCP/DCCP source port selection to no longer favor even
     source port at connect() time when IP_LOCAL_PORT_RANGE is set. This
     lowers the time taken by connect() for hosts having many active
     connections to the same destination

   - Refactor the TCP bind conflict code, shrinking related socket
     structs

   - Refactor TCP SYN-Cookie handling, as a preparation step to allow
     arbitrary SYN-Cookie processing via eBPF

   - Tune optmem_max for 0-copy usage, increasing the default value to
     128KB and namespecifying it

   - Allow coalescing for cloned skbs coming from page pools, improving
     RX performances with some common configurations

   - Reduce extension header parsing overhead at GRO time

   - Add bridge MDB bulk deletion support, allowing user-space to
     request the deletion of matching entries

   - Reorder nftables struct members, to keep data accessed by the
     datapath first

   - Introduce TC block ports tracking and use. This allows supporting
     multicast-like behavior at the TC layer

   - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
     classifiers (RSVP and tcindex)

   - More data-race annotations

   - Extend the diag interface to dump TCP bound-only sockets

   - Conditional notification of events for TC qdisc class and actions

   - Support for WPAN dynamic associations with nearby devices, to form
     a sub-network using a specific PAN ID

   - Implement SMCv2.1 virtual ISM device support

   - Add support for Batman-avd mulicast packet type

  BPF:

   - Tons of verifier improvements:
       - BPF register bounds logic and range support along with a large
         test suite
       - log improvements
       - complete precision tracking support for register spills
       - track aligned STACK_ZERO cases as imprecise spilled registers.
         This improves the verifier "instructions processed" metric from
         single digit to 50-60% for some programs
       - support for user's global BPF subprogram arguments with few
         commonly requested annotations for a better developer
         experience
       - support tracking of BPF_JNE which helps cases when the compiler
         transforms (unsigned) "a &gt; 0" into "if a == 0 goto xxx" and the
         like
       - several fixes

   - Add initial TX metadata implementation for AF_XDP with support in
     mlx5 and stmmac drivers. Two types of offloads are supported right
     now, that is, TX timestamp and TX checksum offload

   - Fix kCFI bugs in BPF all forms of indirect calls from BPF into
     kernel and from kernel into BPF work with CFI enabled. This allows
     BPF to work with CONFIG_FINEIBT=y

   - Change BPF verifier logic to validate global subprograms lazily
     instead of unconditionally before the main program, so they can be
     guarded using BPF CO-RE techniques

   - Support uid/gid options when mounting bpffs

   - Add a new kfunc which acquires the associated cgroup of a task
     within a specific cgroup v1 hierarchy where the latter is
     identified by its id

   - Extend verifier to allow bpf_refcount_acquire() of a map value
     field obtained via direct load which is a use-case needed in
     sched_ext

   - Add BPF link_info support for uprobe multi link along with bpftool
     integration for the latter

   - Support for VLAN tag in XDP hints

   - Remove deprecated bpfilter kernel leftovers given the project is
     developed in user-space (https://github.com/facebook/bpfilter)

  Misc:

   - Support for parellel TC self-tests execution

   - Increase MPTCP self-tests coverage

   - Updated the bridge documentation, including several so-far
     undocumented features

   - Convert all the net self-tests to run in unique netns, to avoid
     random failures due to conflict and allow concurrent runs

   - Add TCP-AO self-tests

   - Add kunit tests for both cfg80211 and mac80211

   - Autogenerate Netlink families documentation from YAML spec

   - Add yml-gen support for fixed headers and recursive nests, the tool
     can now generate user-space code for all genetlink families for
     which we have specs

   - A bunch of additional module descriptions fixes

   - Catch incorrect freeing of pages belonging to a page pool

  Driver API:

   - Rust abstractions for network PHY drivers; do not cover yet the
     full C API, but already allow implementing functional PHY drivers
     in rust

   - Introduce queue and NAPI support in the netdev Netlink interface,
     allowing complete access to the device &lt;&gt; NAPIs &lt;&gt; queues
     relationship

   - Introduce notifications filtering for devlink to allow control
     application scale to thousands of instances

   - Improve PHY validation, requesting rate matching information for
     each ethtool link mode supported by both the PHY and host

   - Add support for ethtool symmetric-xor RSS hash

   - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
     platform

   - Expose pin fractional frequency offset value over new DPLL generic
     netlink attribute

   - Convert older drivers to platform remove callback returning void

   - Add support for PHY package MMD read/write

  New hardware / drivers:

   - Ethernet:
       - Octeon CN10K devices
       - Broadcom 5760X P7
       - Qualcomm SM8550 SoC
       - Texas Instrument DP83TG720S PHY

   - Bluetooth:
       - IMC Networks Bluetooth radio

  Removed:

   - WiFi:
       - libertas 16-bit PCMCIA support
       - Atmel at76c50x drivers
       - HostAP ISA/PCMCIA style 802.11b driver
       - zd1201 802.11b USB dongles
       - Orinoco ISA/PCMCIA 802.11b driver
       - Aviator/Raytheon driver
       - Planet WL3501 driver
       - RNDIS USB 802.11b driver

  Driver updates:

   - Ethernet high-speed NICs:
       - Intel (100G, ice, idpf):
          - allow one by one port representors creation and removal
          - add temperature and clock information reporting
          - add get/set for ethtool's header split ringparam
          - add again FW logging
          - adds support switchdev hardware packet mirroring
          - iavf: implement symmetric-xor RSS hash
          - igc: add support for concurrent physical and free-running
            timers
          - i40e: increase the allowable descriptors
       - nVidia/Mellanox:
          - Preparation for Socket-Direct multi-dev netdev. That will
            allow in future releases combining multiple PFs devices
            attached to different NUMA nodes under the same netdev
       - Broadcom (bnxt):
          - TX completion handling improvements
          - add basic ntuple filter support
          - reduce MSIX vectors usage for MQPRIO offload
          - add VXLAN support, USO offload and TX coalesce completion
            for P7
       - Marvell Octeon EP:
          - xmit-more support
          - add PF-VF mailbox support and use it for FW notifications
            for VFs
       - Wangxun (ngbe/txgbe):
          - implement ethtool functions to operate pause param, ring
            param, coalesce channel number and msglevel
       - Netronome/Corigine (nfp):
          - add flow-steering support
          - support UDP segmentation offload

   - Ethernet NICs embedded, slower, virtual:
       - Xilinx AXI: remove duplicate DMA code adopting the dma engine
         driver
       - stmmac: add support for HW-accelerated VLAN stripping
       - TI AM654x sw: add mqprio, frame preemption &amp; coalescing
       - gve: add support for non-4k page sizes.
       - virtio-net: support dynamic coalescing moderation

   - nVidia/Mellanox Ethernet datacenter switches:
       - allow firmware upgrade without a reboot
       - more flexible support for bridge flooding via the compressed
         FID flooding mode

   - Ethernet embedded switches:
       - Microchip:
          - fine-tune flow control and speed configurations in KSZ8xxx
          - KSZ88X3: enable setting rmii reference
       - Renesas:
          - add jumbo frames support
       - Marvell:
          - 88E6xxx: add "eth-mac" and "rmon" stats support

   - Ethernet PHYs:
       - aquantia: add firmware load support
       - at803x: refactor the driver to simplify adding support for more
         chip variants
       - NXP C45 TJA11xx: Add MACsec offload support

   - Wifi:
       - MediaTek (mt76):
          - NVMEM EEPROM improvements
          - mt7996 Extremely High Throughput (EHT) improvements
          - mt7996 Wireless Ethernet Dispatcher (WED) support
          - mt7996 36-bit DMA support
       - Qualcomm (ath12k):
          - support for a single MSI vector
          - WCN7850: support AP mode
       - Intel (iwlwifi):
          - new debugfs file fw_dbg_clear
          - allow concurrent P2P operation on DFS channels

   - Bluetooth:
       - QCA2066: support HFP offload
       - ISO: more broadcast-related improvements
       - NXP: better recovery in case receiver/transmitter get out of sync"

* tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1714 commits)
  lan78xx: remove redundant statement in lan78xx_get_eee
  lan743x: remove redundant statement in lan743x_ethtool_get_eee
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_rx_flow_steer()
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_srxclsrldel()
  bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()
  tcp: Revert no longer abort SYN_SENT when receiving some ICMP
  Revert "mlx5 updates 2023-12-20"
  Revert "net: stmmac: Enable Per DMA Channel interrupt"
  ipvlan: Remove usage of the deprecated ida_simple_xx() API
  ipvlan: Fix a typo in a comment
  net/sched: Remove ipt action tests
  net: stmmac: Use interrupt mode INTM=1 for per channel irq
  net: stmmac: Add support for TX/RX channel interrupt
  net: stmmac: Make MSI interrupt routine generic
  dt-bindings: net: snps,dwmac: per channel irq
  net: phy: at803x: make read_status more generic
  net: phy: at803x: add support for cdt cross short test for qca808x
  net: phy: at803x: refactor qca808x cable test get status function
  net: phy: at803x: generalize cdt fault length function
  net: ethernet: cortina: Drop TSO support
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER</title>
<updated>2024-01-08T23:27:15+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2023-12-28T14:47:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5e0a760b44417f7cadd79de2204d6247109558a0'/>
<id>5e0a760b44417f7cadd79de2204d6247109558a0</id>
<content type='text'>
commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive.  This has caused
issues with code that was not yet upstream and depended on the previous
definition.

To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.

Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive.  This has caused
issues with code that was not yet upstream and depended on the previous
definition.

To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.

Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, treewide: introduce NR_PAGE_ORDERS</title>
<updated>2024-01-08T23:27:15+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2023-12-28T14:47:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fd37721803c6e73619108f76ad2e12a9aa5fafaf'/>
<id>fd37721803c6e73619108f76ad2e12a9aa5fafaf</id>
<content type='text'>
NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.

NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.

[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
  Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.

NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.

[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
  Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, kasan: use KASAN_TAG_KERNEL instead of 0xff</title>
<updated>2023-12-29T19:58:44+00:00</updated>
<author>
<name>Andrey Konovalov</name>
<email>andreyknvl@google.com</email>
</author>
<published>2023-12-21T20:04:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5cb6674b694b84803cbee8bfccaa2bfdfeb6eae4'/>
<id>5cb6674b694b84803cbee8bfccaa2bfdfeb6eae4</id>
<content type='text'>
Use the KASAN_TAG_KERNEL marco instead of open-coding 0xff in the mm code.
This macro is provided by include/linux/kasan-tags.h, which does not
include any other headers, so it's safe to include it into mm.h without
causing circular include dependencies.

Link: https://lkml.kernel.org/r/71db9087b0aebb6c4dccbc609cc0cd50621533c7.1703188911.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the KASAN_TAG_KERNEL marco instead of open-coding 0xff in the mm code.
This macro is provided by include/linux/kasan-tags.h, which does not
include any other headers, so it's safe to include it into mm.h without
causing circular include dependencies.

Link: https://lkml.kernel.org/r/71db9087b0aebb6c4dccbc609cc0cd50621533c7.1703188911.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: page_alloc: simplify __free_pages_ok()</title>
<updated>2023-12-20T22:48:14+00:00</updated>
<author>
<name>Yajun Deng</name>
<email>yajun.deng@linux.dev</email>
</author>
<published>2023-12-16T03:05:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=250ae189d98290d0539b4f9b8c4703e0bf24f9d3'/>
<id>250ae189d98290d0539b4f9b8c4703e0bf24f9d3</id>
<content type='text'>
There is redundant code in __free_pages_ok(). Use free_one_page()
simplify it.

Link: https://lkml.kernel.org/r/20231216030503.2126130-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng &lt;yajun.deng@linux.dev&gt;
Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is redundant code in __free_pages_ok(). Use free_one_page()
simplify it.

Link: https://lkml.kernel.org/r/20231216030503.2126130-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng &lt;yajun.deng@linux.dev&gt;
Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: page_alloc: unreserve highatomic page blocks before oom</title>
<updated>2023-12-11T00:51:52+00:00</updated>
<author>
<name>Charan Teja Kalla</name>
<email>quic_charante@quicinc.com</email>
</author>
<published>2023-11-24T10:57:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ac3f3b0a55518056bc80ed32a41931c99e1f7d81'/>
<id>ac3f3b0a55518056bc80ed32a41931c99e1f7d81</id>
<content type='text'>
__alloc_pages_direct_reclaim() is called from slowpath allocation where
high atomic reserves can be unreserved after there is a progress in
reclaim and yet no suitable page is found.  Later should_reclaim_retry()
gets called from slow path allocation to decide if the reclaim needs to be
retried before OOM kill path is taken.

should_reclaim_retry() checks the available(reclaimable + free pages)
memory against the min wmark levels of a zone and returns:

a) true, if it is above the min wmark so that slow path allocation will
   do the reclaim retries.

b) false, thus slowpath allocation takes oom kill path.

should_reclaim_retry() can also unreserves the high atomic reserves **but
only after all the reclaim retries are exhausted.**

In a case where there are almost none reclaimable memory and free pages
contains mostly the high atomic reserves but allocation context can't use
these high atomic reserves, makes the available memory below min wmark
levels hence false is returned from should_reclaim_retry() leading the
allocation request to take OOM kill path.  This can turn into a early oom
kill if high atomic reserves are holding lot of free memory and
unreserving of them is not attempted.

(early)OOM is encountered on a VM with the below state:
[  295.998653] Normal free:7728kB boost:0kB min:804kB low:1004kB
high:1204kB reserved_highatomic:8192KB active_anon:4kB inactive_anon:0kB
active_file:24kB inactive_file:24kB unevictable:1220kB writepending:0kB
present:70732kB managed:49224kB mlocked:0kB bounce:0kB free_pcp:688kB
local_pcp:492kB free_cma:0kB
[  295.998656] lowmem_reserve[]: 0 32
[  295.998659] Normal: 508*4kB (UMEH) 241*8kB (UMEH) 143*16kB (UMEH)
33*32kB (UH) 7*64kB (UH) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB
0*4096kB = 7752kB

Per above log, the free memory of ~7MB exist in the high atomic reserves
is not freed up before falling back to oom kill path.

Fix it by trying to unreserve the high atomic reserves in
should_reclaim_retry() before __alloc_pages_direct_reclaim() can fallback
to oom kill path.

Link: https://lkml.kernel.org/r/1700823445-27531-1-git-send-email-quic_charante@quicinc.com
Fixes: 0aaa29a56e4f ("mm, page_alloc: reserve pageblocks for high-order atomic allocations on demand")
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Reported-by: Chris Goldsworthy &lt;quic_cgoldswo@quicinc.com&gt;
Suggested-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Chris Goldsworthy &lt;quic_cgoldswo@quicinc.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__alloc_pages_direct_reclaim() is called from slowpath allocation where
high atomic reserves can be unreserved after there is a progress in
reclaim and yet no suitable page is found.  Later should_reclaim_retry()
gets called from slow path allocation to decide if the reclaim needs to be
retried before OOM kill path is taken.

should_reclaim_retry() checks the available(reclaimable + free pages)
memory against the min wmark levels of a zone and returns:

a) true, if it is above the min wmark so that slow path allocation will
   do the reclaim retries.

b) false, thus slowpath allocation takes oom kill path.

should_reclaim_retry() can also unreserves the high atomic reserves **but
only after all the reclaim retries are exhausted.**

In a case where there are almost none reclaimable memory and free pages
contains mostly the high atomic reserves but allocation context can't use
these high atomic reserves, makes the available memory below min wmark
levels hence false is returned from should_reclaim_retry() leading the
allocation request to take OOM kill path.  This can turn into a early oom
kill if high atomic reserves are holding lot of free memory and
unreserving of them is not attempted.

(early)OOM is encountered on a VM with the below state:
[  295.998653] Normal free:7728kB boost:0kB min:804kB low:1004kB
high:1204kB reserved_highatomic:8192KB active_anon:4kB inactive_anon:0kB
active_file:24kB inactive_file:24kB unevictable:1220kB writepending:0kB
present:70732kB managed:49224kB mlocked:0kB bounce:0kB free_pcp:688kB
local_pcp:492kB free_cma:0kB
[  295.998656] lowmem_reserve[]: 0 32
[  295.998659] Normal: 508*4kB (UMEH) 241*8kB (UMEH) 143*16kB (UMEH)
33*32kB (UH) 7*64kB (UH) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB
0*4096kB = 7752kB

Per above log, the free memory of ~7MB exist in the high atomic reserves
is not freed up before falling back to oom kill path.

Fix it by trying to unreserve the high atomic reserves in
should_reclaim_retry() before __alloc_pages_direct_reclaim() can fallback
to oom kill path.

Link: https://lkml.kernel.org/r/1700823445-27531-1-git-send-email-quic_charante@quicinc.com
Fixes: 0aaa29a56e4f ("mm, page_alloc: reserve pageblocks for high-order atomic allocations on demand")
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Reported-by: Chris Goldsworthy &lt;quic_cgoldswo@quicinc.com&gt;
Suggested-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Chris Goldsworthy &lt;quic_cgoldswo@quicinc.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: page_alloc: enforce minimum zone size to do high atomic reserves</title>
<updated>2023-12-11T00:51:52+00:00</updated>
<author>
<name>Charan Teja Kalla</name>
<email>quic_charante@quicinc.com</email>
</author>
<published>2023-11-24T11:05:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9cd20f3fe045af95a8fe7a12328b21bfd2f3b8bf'/>
<id>9cd20f3fe045af95a8fe7a12328b21bfd2f3b8bf</id>
<content type='text'>
Highatomic reserves are set to roughly 1% of zone for maximum and a
pageblock size for minimum.  Encountered a system with the below
configuration:
Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB
reserved_highatomic:8192KB managed:49224kB

On such systems, even a single pageblock makes highatomic reserves are set
to ~8% of the zone memory.  This high value can easily exert pressure on
the zone.

Per discussion with Michal and Mel, it is not much useful to reserve the
memory for highatomic allocations on such small systems[1].  Since the
minimum size for high atomic reserves is always going to be a pageblock
size and if 1% of zone managed pages is going to be below pageblock size,
don't reserve memory for high atomic allocations.  Thanks Michal for this
suggestion[2].

Since no memory is being reserved for high atomic allocations and if
respective allocation failures are seen, this patch can be reverted.

[1] https://lore.kernel.org/linux-mm/20231117161956.d3yjdxhhm4rhl7h2@techsingularity.net/
[2] https://lore.kernel.org/linux-mm/ZVYRJMUitykepLRy@tiehlicka/

Link: https://lkml.kernel.org/r/c3a2a48e2cfe08176a80eaf01c110deb9e918055.1700821416.git.quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Highatomic reserves are set to roughly 1% of zone for maximum and a
pageblock size for minimum.  Encountered a system with the below
configuration:
Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB
reserved_highatomic:8192KB managed:49224kB

On such systems, even a single pageblock makes highatomic reserves are set
to ~8% of the zone memory.  This high value can easily exert pressure on
the zone.

Per discussion with Michal and Mel, it is not much useful to reserve the
memory for highatomic allocations on such small systems[1].  Since the
minimum size for high atomic reserves is always going to be a pageblock
size and if 1% of zone managed pages is going to be below pageblock size,
don't reserve memory for high atomic allocations.  Thanks Michal for this
suggestion[2].

Since no memory is being reserved for high atomic allocations and if
respective allocation failures are seen, this patch can be reverted.

[1] https://lore.kernel.org/linux-mm/20231117161956.d3yjdxhhm4rhl7h2@techsingularity.net/
[2] https://lore.kernel.org/linux-mm/ZVYRJMUitykepLRy@tiehlicka/

Link: https://lkml.kernel.org/r/c3a2a48e2cfe08176a80eaf01c110deb9e918055.1700821416.git.quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: page_alloc: correct high atomic reserve calculations</title>
<updated>2023-12-11T00:51:51+00:00</updated>
<author>
<name>Charan Teja Kalla</name>
<email>quic_charante@quicinc.com</email>
</author>
<published>2023-11-24T11:05:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d68e39fc45f70e35eb74df2128d315c1d91e4dc4'/>
<id>d68e39fc45f70e35eb74df2128d315c1d91e4dc4</id>
<content type='text'>
Patch series "mm: page_alloc: fixes for high atomic reserve
caluculations", v3.

The state of the system where the issue exposed shown in oom kill logs:

[  295.998653] Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB reserved_highatomic:8192KB active_anon:4kB inactive_anon:0kB active_file:24kB inactive_file:24kB unevictable:1220kB writepending:0kB present:70732kB managed:49224kB mlocked:0kB bounce:0kB free_pcp:688kBlocal_pcp:492kB free_cma:0kB
[  295.998656] lowmem_reserve[]: 0 32
[  295.998659] Normal: 508*4kB (UMEH) 241*8kB (UMEH) 143*16kB (UMEH)
33*32kB (UH) 7*64kB (UH) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 7752kB

From the above, it is seen that ~16MB of memory reserved for high atomic
reserves against the expectation of 1% reserves which is fixed in the 1st
patch.

Don't reserve the high atomic page blocks if 1% of zone memory size is
below a pageblock size.


This patch (of 2):

reserve_highatomic_pageblock() aims to reserve the 1% of the managed pages
of a zone, which is used for the high order atomic allocations.

It uses the below calculation to reserve:
static void reserve_highatomic_pageblock(struct page *page, ....) {

   .......
   max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;

   if (zone-&gt;nr_reserved_highatomic &gt;= max_managed)
       goto out;

   zone-&gt;nr_reserved_highatomic += pageblock_nr_pages;
   set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
   move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);

out:
   ....
}

Since we are always appending the 1% of zone managed pages count to
pageblock_nr_pages, the minimum it is turning into 2 pageblocks as the
nr_reserved_highatomic is incremented/decremented in pageblock sizes.

Encountered a system(actually a VM running on the Linux kernel) with the
below zone configuration:
Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB
reserved_highatomic:8192KB managed:49224kB

The existing calculations making it to reserve the 8MB(with pageblock size
of 4MB) i.e.  16% of the zone managed memory.  Reserving such high amount
of memory can easily exert memory pressure in the system thus may lead
into unnecessary reclaims till unreserving of high atomic reserves.

Since high atomic reserves are managed in pageblock size granules, as
MIGRATE_HIGHATOMIC is set for such pageblock, fix the calculations for
high atomic reserves as, minimum is pageblock size , maximum is
approximately 1% of the zone managed pages.

Link: https://lkml.kernel.org/r/cover.1700821416.git.quic_charante@quicinc.com
Link: https://lkml.kernel.org/r/1660034138397b82a0a8b6ae51cbe96bd583d89e.1700821416.git.quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Acked-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "mm: page_alloc: fixes for high atomic reserve
caluculations", v3.

The state of the system where the issue exposed shown in oom kill logs:

[  295.998653] Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB reserved_highatomic:8192KB active_anon:4kB inactive_anon:0kB active_file:24kB inactive_file:24kB unevictable:1220kB writepending:0kB present:70732kB managed:49224kB mlocked:0kB bounce:0kB free_pcp:688kBlocal_pcp:492kB free_cma:0kB
[  295.998656] lowmem_reserve[]: 0 32
[  295.998659] Normal: 508*4kB (UMEH) 241*8kB (UMEH) 143*16kB (UMEH)
33*32kB (UH) 7*64kB (UH) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 7752kB

From the above, it is seen that ~16MB of memory reserved for high atomic
reserves against the expectation of 1% reserves which is fixed in the 1st
patch.

Don't reserve the high atomic page blocks if 1% of zone memory size is
below a pageblock size.


This patch (of 2):

reserve_highatomic_pageblock() aims to reserve the 1% of the managed pages
of a zone, which is used for the high order atomic allocations.

It uses the below calculation to reserve:
static void reserve_highatomic_pageblock(struct page *page, ....) {

   .......
   max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;

   if (zone-&gt;nr_reserved_highatomic &gt;= max_managed)
       goto out;

   zone-&gt;nr_reserved_highatomic += pageblock_nr_pages;
   set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
   move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);

out:
   ....
}

Since we are always appending the 1% of zone managed pages count to
pageblock_nr_pages, the minimum it is turning into 2 pageblocks as the
nr_reserved_highatomic is incremented/decremented in pageblock sizes.

Encountered a system(actually a VM running on the Linux kernel) with the
below zone configuration:
Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB
reserved_highatomic:8192KB managed:49224kB

The existing calculations making it to reserve the 8MB(with pageblock size
of 4MB) i.e.  16% of the zone managed memory.  Reserving such high amount
of memory can easily exert memory pressure in the system thus may lead
into unnecessary reclaims till unreserving of high atomic reserves.

Since high atomic reserves are managed in pageblock size granules, as
MIGRATE_HIGHATOMIC is set for such pageblock, fix the calculations for
high atomic reserves as, minimum is pageblock size , maximum is
approximately 1% of the zone managed pages.

Link: https://lkml.kernel.org/r/cover.1700821416.git.quic_charante@quicinc.com
Link: https://lkml.kernel.org/r/1660034138397b82a0a8b6ae51cbe96bd583d89e.1700821416.git.quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Acked-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/page_alloc: dedupe some memcg uncharging logic</title>
<updated>2023-12-11T00:51:39+00:00</updated>
<author>
<name>Brendan Jackman</name>
<email>jackmanb@google.com</email>
</author>
<published>2023-11-08T16:49:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=17b46e7beb8fe4e4807f70aaa615cf50a5ba9d3a'/>
<id>17b46e7beb8fe4e4807f70aaa615cf50a5ba9d3a</id>
<content type='text'>
The duplication makes it seem like some work is required before uncharging
in the !PageHWPoison case.  But it isn't, so we can simplify the code a
little.

Note the PageMemcgKmem check is redundant, but I've left it in as it
avoids an unnecessary function call.

Link: https://lkml.kernel.org/r/20231108164920.3401565-1-jackmanb@google.com
Signed-off-by: Brendan Jackman &lt;jackmanb@google.com&gt;
Reviewed-by: Yosry Ahmed &lt;yosryahmed@google.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The duplication makes it seem like some work is required before uncharging
in the !PageHWPoison case.  But it isn't, so we can simplify the code a
little.

Note the PageMemcgKmem check is redundant, but I've left it in as it
avoids an unnecessary function call.

Link: https://lkml.kernel.org/r/20231108164920.3401565-1-jackmanb@google.com
Signed-off-by: Brendan Jackman &lt;jackmanb@google.com&gt;
Reviewed-by: Yosry Ahmed &lt;yosryahmed@google.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
