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  1. 26 6月, 2023 3 次提交
  3. 25 6月, 2023 8 次提交
  5. 21 6月, 2023 1 次提交
  7. 16 6月, 2023 1 次提交
  9. 13 6月, 2023 1 次提交
  11. 07 6月, 2023 6 次提交
  13. 30 5月, 2023 7 次提交
  15. 19 5月, 2023 6 次提交
    • N
      memcg: support ksm merge any mode per cgroup · 0f6fb357
      由 Nanyong Sun 提交于 
      hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I72R0B
CVE: NA

----------------------------------------------------------------------

Add control file "memory.ksm" to enable ksm per cgroup.
Echo to 1 will set all tasks currently in the cgroup to ksm merge
any mode, which means ksm gets enabled for all vma's of a process.
Meanwhile echo to 0 will disable ksm for them and unmerge the
merged pages.
Cat the file will show the above state and ksm related profits
of this cgroup.
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
      0f6fb357
    • D
      mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0 · 351ceedb
      由 David Hildenbrand 提交于 
      mainline inclusion
from mainline-v6.4-rc1
commit 24139c07
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I72R0B
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=24139c07f413ef4b555482c758343d71392a19bc

----------------------------------------------------------------------

Patch series "mm/ksm: improve PR_SET_MEMORY_MERGE=0 handling and cleanup
disabling KSM", v2.

(1) Make PR_SET_MEMORY_MERGE=0 unmerge pages like setting MADV_UNMERGEABLE
does, (2) add a selftest for it and (3) factor out disabling of KSM from
s390/gmap code.

This patch (of 3):

Let's unmerge any KSM pages when setting PR_SET_MEMORY_MERGE=0, and clear
the VM_MERGEABLE flag from all VMAs -- just like KSM would.  Of course,
only do that if we previously set PR_SET_MEMORY_MERGE=1.

Link: https://lkml.kernel.org/r/20230422205420.30372-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230422205420.30372-2-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NStefan Roesch <shr@devkernel.io>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	mm/ksm.c
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
      351ceedb
    • S
      mm: add new KSM process and sysfs knobs · a098d41e
      由 Stefan Roesch 提交于 
      mainline inclusion
from mainline-v6.4-rc1
commit d21077fb
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I72R0B
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d21077fbc2fc987c2e593c34dc3b4d84e546dc9f

----------------------------------------------------------------------

This adds the general_profit KSM sysfs knob and the process profit metric
knobs to ksm_stat.

1) expose general_profit metric

   The documentation mentions a general profit metric, however this
   metric is not calculated.  In addition the formula depends on the size
   of internal structures, which makes it more difficult for an
   administrator to make the calculation.  Adding the metric for a better
   user experience.

2) document general_profit sysfs knob

3) calculate ksm process profit metric

   The ksm documentation mentions the process profit metric and how to
   calculate it.  This adds the calculation of the metric.

4) mm: expose ksm process profit metric in ksm_stat

   This exposes the ksm process profit metric in /proc/<pid>/ksm_stat.
   The documentation mentions the formula for the ksm process profit
   metric, however it does not calculate it.  In addition the formula
   depends on the size of internal structures.  So it makes sense to
   expose it.

5) document new procfs ksm knobs

Link: https://lkml.kernel.org/r/20230418051342.1919757-3-shr@devkernel.ioSigned-off-by: NStefan Roesch <shr@devkernel.io>
Reviewed-by: NBagas Sanjaya <bagasdotme@gmail.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
      a098d41e
    • S
      mm: add new api to enable ksm per process · 2cd2cdfe
      由 Stefan Roesch 提交于 
      mainline inclusion
from mainline-v6.4-rc1
commit d7597f59
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I72R0B
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d7597f59d1d33e9efbffa7060deb9ee5bd119e62

----------------------------------------------------------------------

Patch series "mm: process/cgroup ksm support", v9.

So far KSM can only be enabled by calling madvise for memory regions.  To
be able to use KSM for more workloads, KSM needs to have the ability to be
enabled / disabled at the process / cgroup level.

Use case 1:
  The madvise call is not available in the programming language.  An
  example for this are programs with forked workloads using a garbage
  collected language without pointers.  In such a language madvise cannot
  be made available.

  In addition the addresses of objects get moved around as they are
  garbage collected.  KSM sharing needs to be enabled "from the outside"
  for these type of workloads.

Use case 2:
  The same interpreter can also be used for workloads where KSM brings
  no benefit or even has overhead.  We'd like to be able to enable KSM on
  a workload by workload basis.

Use case 3:
  With the madvise call sharing opportunities are only enabled for the
  current process: it is a workload-local decision.  A considerable number
  of sharing opportunities may exist across multiple workloads or jobs (if
  they are part of the same security domain).  Only a higler level entity
  like a job scheduler or container can know for certain if its running
  one or more instances of a job.  That job scheduler however doesn't have
  the necessary internal workload knowledge to make targeted madvise
  calls.

Security concerns:

  In previous discussions security concerns have been brought up.  The
  problem is that an individual workload does not have the knowledge about
  what else is running on a machine.  Therefore it has to be very
  conservative in what memory areas can be shared or not.  However, if the
  system is dedicated to running multiple jobs within the same security
  domain, its the job scheduler that has the knowledge that sharing can be
  safely enabled and is even desirable.

Performance:

  Experiments with using UKSM have shown a capacity increase of around 20%.

  Here are the metrics from an instagram workload (taken from a machine
  with 64GB main memory):

   full_scans: 445
   general_profit: 20158298048
   max_page_sharing: 256
   merge_across_nodes: 1
   pages_shared: 129547
   pages_sharing: 5119146
   pages_to_scan: 4000
   pages_unshared: 1760924
   pages_volatile: 10761341
   run: 1
   sleep_millisecs: 20
   stable_node_chains: 167
   stable_node_chains_prune_millisecs: 2000
   stable_node_dups: 2751
   use_zero_pages: 0
   zero_pages_sharing: 0

After the service is running for 30 minutes to an hour, 4 to 5 million
shared pages are common for this workload when using KSM.

Detailed changes:

1. New options for prctl system command
   This patch series adds two new options to the prctl system call.
   The first one allows to enable KSM at the process level and the second
   one to query the setting.

The setting will be inherited by child processes.

With the above setting, KSM can be enabled for the seed process of a cgroup
and all processes in the cgroup will inherit the setting.

2. Changes to KSM processing
   When KSM is enabled at the process level, the KSM code will iterate
   over all the VMA's and enable KSM for the eligible VMA's.

   When forking a process that has KSM enabled, the setting will be
   inherited by the new child process.

3. Add general_profit metric
   The general_profit metric of KSM is specified in the documentation,
   but not calculated.  This adds the general profit metric to
   /sys/kernel/debug/mm/ksm.

4. Add more metrics to ksm_stat
   This adds the process profit metric to /proc/<pid>/ksm_stat.

5. Add more tests to ksm_tests and ksm_functional_tests
   This adds an option to specify the merge type to the ksm_tests.
   This allows to test madvise and prctl KSM.

   It also adds a two new tests to ksm_functional_tests: one to test
   the new prctl options and the other one is a fork test to verify that
   the KSM process setting is inherited by client processes.

This patch (of 3):

So far KSM can only be enabled by calling madvise for memory regions.  To
be able to use KSM for more workloads, KSM needs to have the ability to be
enabled / disabled at the process / cgroup level.

1. New options for prctl system command

   This patch series adds two new options to the prctl system call.
   The first one allows to enable KSM at the process level and the second
   one to query the setting.

   The setting will be inherited by child processes.

   With the above setting, KSM can be enabled for the seed process of a
   cgroup and all processes in the cgroup will inherit the setting.

2. Changes to KSM processing

   When KSM is enabled at the process level, the KSM code will iterate
   over all the VMA's and enable KSM for the eligible VMA's.

   When forking a process that has KSM enabled, the setting will be
   inherited by the new child process.

  1) Introduce new MMF_VM_MERGE_ANY flag

     This introduces the new flag MMF_VM_MERGE_ANY flag.  When this flag
     is set, kernel samepage merging (ksm) gets enabled for all vma's of a
     process.

  2) Setting VM_MERGEABLE on VMA creation

     When a VMA is created, if the MMF_VM_MERGE_ANY flag is set, the
     VM_MERGEABLE flag will be set for this VMA.

  3) support disabling of ksm for a process

     This adds the ability to disable ksm for a process if ksm has been
     enabled for the process with prctl.

  4) add new prctl option to get and set ksm for a process

     This adds two new options to the prctl system call
     - enable ksm for all vmas of a process (if the vmas support it).
     - query if ksm has been enabled for a process.

3. Disabling MMF_VM_MERGE_ANY for storage keys in s390

   In the s390 architecture when storage keys are used, the
   MMF_VM_MERGE_ANY will be disabled.

Link: https://lkml.kernel.org/r/20230418051342.1919757-1-shr@devkernel.io
Link: https://lkml.kernel.org/r/20230418051342.1919757-2-shr@devkernel.ioSigned-off-by: NStefan Roesch <shr@devkernel.io>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	kernel/sys.c mm/ksm.c mm/mmap.c
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
      2cd2cdfe
    • X
      ksm: count allocated ksm rmap_items for each process · 8c3ecf85
      由 xu xin 提交于 
      mainline inclusion
from mainline-v6.1-rc1
commit cb4df4ca
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I72R0B
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cb4df4cae4f2bd8cf7a32eff81178fce31600f7c

----------------------------------------------------------------------

Patch series "ksm: count allocated rmap_items and update documentation",
v5.

KSM can save memory by merging identical pages, but also can consume
additional memory, because it needs to generate rmap_items to save each
scanned page's brief rmap information.

To determine how beneficial the ksm-policy (like madvise), they are using
brings, so we add a new interface /proc/<pid>/ksm_stat for each process
The value "ksm_rmap_items" in it indicates the total allocated ksm
rmap_items of this process.

The detailed description can be seen in the following patches' commit
message.

This patch (of 2):

KSM can save memory by merging identical pages, but also can consume
additional memory, because it needs to generate rmap_items to save each
scanned page's brief rmap information.  Some of these pages may be merged,
but some may not be abled to be merged after being checked several times,
which are unprofitable memory consumed.

The information about whether KSM save memory or consume memory in
system-wide range can be determined by the comprehensive calculation of
pages_sharing, pages_shared, pages_unshared and pages_volatile.  A simple
approximate calculation:

	profit =~ pages_sharing * sizeof(page) - (all_rmap_items) *
	         sizeof(rmap_item);

where all_rmap_items equals to the sum of pages_sharing, pages_shared,
pages_unshared and pages_volatile.

But we cannot calculate this kind of ksm profit inner single-process wide
because the information of ksm rmap_item's number of a process is lacked.
For user applications, if this kind of information could be obtained, it
helps upper users know how beneficial the ksm-policy (like madvise) they
are using brings, and then optimize their app code.  For example, one
application madvise 1000 pages as MERGEABLE, while only a few pages are
really merged, then it's not cost-efficient.

So we add a new interface /proc/<pid>/ksm_stat for each process in which
the value of ksm_rmap_itmes is only shown now and so more values can be
added in future.

So similarly, we can calculate the ksm profit approximately for a single
process by:

	profit =~ ksm_merging_pages * sizeof(page) - ksm_rmap_items *
		 sizeof(rmap_item);

where ksm_merging_pages is shown at /proc/<pid>/ksm_merging_pages, and
ksm_rmap_items is shown in /proc/<pid>/ksm_stat.

Link: https://lkml.kernel.org/r/20220830143731.299702-1-xu.xin16@zte.com.cn
Link: https://lkml.kernel.org/r/20220830143838.299758-1-xu.xin16@zte.com.cnSigned-off-by: Nxu xin <xu.xin16@zte.com.cn>
Reviewed-by: NXiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: NYang Yang <yang.yang29@zte.com.cn>
Signed-off-by: NCGEL ZTE <cgel.zte@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	include/linux/mm_types.h
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
      8c3ecf85
    • X
      ksm: count ksm merging pages for each process · 44acbc78
      由 xu xin 提交于 
      mainline inclusion
from mainline-v5.19-rc1
commit 76093853
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I72R0B
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7609385337a4feb6236e42dcd0df2185683ce839

----------------------------------------------------------------------

Some applications or containers want to use KSM by calling madvise() to
advise areas of address space to be MERGEABLE.  But they may not know
which applications are more likely to cause real merges in the
deployment.  If this patch is applied, it helps them know their
corresponding number of merged pages, and then optimize their app code.

As current KSM only counts the number of KSM merging pages(e.g.
ksm_pages_sharing and ksm_pages_shared) of the whole system, we cannot see
the more fine-grained KSM merging, for the upper application optimization,
the merging area cannot be set easily according to the KSM page merging
probability of each process.  Therefore, it is necessary to add extra
statistical means so that the upper level users can know the detailed KSM
merging information of each process.

We add a new proc file named as ksm_merging_pages under /proc/<pid>/ to
indicate the involved ksm merging pages of this process.

[akpm@linux-foundation.org: fix comment typo, remove BUG_ON()s]
Link: https://lkml.kernel.org/r/20220325082318.2352853-1-xu.xin16@zte.com.cnSigned-off-by: Nxu xin <xu.xin16@zte.com.cn>
Reported-by: Nkernel test robot <lkp@intel.com>
Reviewed-by: NYang Yang <yang.yang29@zte.com.cn>
Reviewed-by: NRan Xiaokai <ran.xiaokai@zte.com.cn>
Reported-by: NZeal Robot <zealci@zte.com.cn>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Ohhoon Kwon <ohoono.kwon@samsung.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	include/linux/mm_types.h
Signed-off-by: NNanyong Sun <sunnanyong@huawei.com>
      44acbc78
  17. 18 5月, 2023 7 次提交