04 Oct, 2022
40 commits
-
Create the new routine remove_inode_single_folio that will remove a single
folio from a file. This is refactored code from remove_inode_hugepages.
It checks for the uncommon case in which the folio is still mapped and
unmaps.No functional change. This refactoring will be put to use and expanded
upon in a subsequent patches.Link: https://lkml.kernel.org/r/20220914221810.95771-5-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz
Reviewed-by: Miaohe Lin
Cc: Andrea Arcangeli
Cc: "Aneesh Kumar K.V"
Cc: Axel Rasmussen
Cc: David Hildenbrand
Cc: Davidlohr Bueso
Cc: James Houghton
Cc: "Kirill A. Shutemov"
Cc: Michal Hocko
Cc: Mina Almasry
Cc: Muchun Song
Cc: Naoya Horiguchi
Cc: Pasha Tatashin
Cc: Peter Xu
Cc: Prakash Sangappa
Cc: Sven Schnelle
Signed-off-by: Andrew Morton -
remove_huge_page removes a hugetlb page from the page cache. Change to
hugetlb_delete_from_page_cache as it is a more descriptive name.
huge_add_to_page_cache is global in scope, but only deals with hugetlb
pages. For consistency and clarity, rename to hugetlb_add_to_page_cache.Link: https://lkml.kernel.org/r/20220914221810.95771-4-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz
Reviewed-by: Miaohe Lin
Cc: Andrea Arcangeli
Cc: "Aneesh Kumar K.V"
Cc: Axel Rasmussen
Cc: David Hildenbrand
Cc: Davidlohr Bueso
Cc: James Houghton
Cc: "Kirill A. Shutemov"
Cc: Michal Hocko
Cc: Mina Almasry
Cc: Muchun Song
Cc: Naoya Horiguchi
Cc: Pasha Tatashin
Cc: Peter Xu
Cc: Prakash Sangappa
Cc: Sven Schnelle
Signed-off-by: Andrew Morton -
Commit c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing
synchronization") added code to take i_mmap_rwsem in read mode for the
duration of fault processing. However, this has been shown to cause
performance/scaling issues. Revert the code and go back to only taking
the semaphore in huge_pmd_share during the fault path.Keep the code that takes i_mmap_rwsem in write mode before calling
try_to_unmap as this is required if huge_pmd_unshare is called.NOTE: Reverting this code does expose the following race condition.
Faulting thread Unsharing thread
... ...
ptep = huge_pte_offset()
or
ptep = huge_pte_alloc()
...
i_mmap_lock_write
lock page table
ptep invalid
Reviewed-by: Miaohe Lin
Cc: Andrea Arcangeli
Cc: "Aneesh Kumar K.V"
Cc: Axel Rasmussen
Cc: David Hildenbrand
Cc: Davidlohr Bueso
Cc: James Houghton
Cc: "Kirill A. Shutemov"
Cc: Michal Hocko
Cc: Mina Almasry
Cc: Muchun Song
Cc: Naoya Horiguchi
Cc: Pasha Tatashin
Cc: Peter Xu
Cc: Prakash Sangappa
Cc: Sven Schnelle
Signed-off-by: Andrew Morton -
Patch series "hugetlb: Use new vma lock for huge pmd sharing
synchronization", v2.hugetlb fault scalability regressions have recently been reported [1].
This is not the first such report, as regressions were also noted when
commit c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing
synchronization") was added [2] in v5.7. At that time, a proposal to
address the regression was suggested [3] but went nowhere.The regression and benefit of this patch series is not evident when
using the vm_scalability benchmark reported in [2] on a recent kernel.
Results from running,
"./usemem -n 48 --prealloc --prefault -O -U 3448054972"48 sample Avg
next-20220913 next-20220913 next-20220913
unmodified revert i_mmap_sema locking vma sema locking, this series
-----------------------------------------------------------------------------
498150 KB/s 501934 KB/s 504793 KB/sThe recent regression report [1] notes page fault and fork latency of
shared hugetlb mappings. To measure this, I created two simple programs:
1) map a shared hugetlb area, write fault all pages, unmap area
Do this in a continuous loop to measure faults per second
2) map a shared hugetlb area, write fault a few pages, fork and exit
Do this in a continuous loop to measure forks per second
These programs were run on a 48 CPU VM with 320GB memory. The shared
mapping size was 250GB. For comparison, a single instance of the program
was run. Then, multiple instances were run in parallel to introduce
lock contention. Changing the locking scheme results in a significant
performance benefit.test instances unmodified revert vma
--------------------------------------------------------------------------
faults per sec 1 393043 395680 389932
faults per sec 24 71405 81191 79048
forks per sec 1 2802 2747 2725
forks per sec 24 439 536 500
Combined faults 24 1621 68070 53662
Combined forks 24 358 67 142Combined test is when running both faulting program and forking program
simultaneously.Patches 1 and 2 of this series revert c0d0381ade79 and 87bf91d39bb5 which
depends on c0d0381ade79. Acquisition of i_mmap_rwsem is still required in
the fault path to establish pmd sharing, so this is moved back to
huge_pmd_share. With c0d0381ade79 reverted, this race is exposed:Faulting thread Unsharing thread
... ...
ptep = huge_pte_offset()
or
ptep = huge_pte_alloc()
...
i_mmap_lock_write
lock page table
ptep invalid
Reviewed-by: Miaohe Lin
Cc: Andrea Arcangeli
Cc: "Aneesh Kumar K.V"
Cc: Axel Rasmussen
Cc: David Hildenbrand
Cc: Davidlohr Bueso
Cc: James Houghton
Cc: "Kirill A. Shutemov"
Cc: Michal Hocko
Cc: Mina Almasry
Cc: Muchun Song
Cc: Naoya Horiguchi
Cc: Pasha Tatashin
Cc: Peter Xu
Cc: Prakash Sangappa
Cc: Sven Schnelle
Signed-off-by: Andrew Morton -
Pointer variables allocate memory first, and then judge. There is no need
to initialize the assignment.Link: https://lkml.kernel.org/r/20220914012113.6271-1-xupengfei@nfschina.com
Signed-off-by: XU pengfei
Reviewed-by: Muchun Song
Cc: Mike Kravetz
Signed-off-by: Andrew Morton -
It's only used in mm/filemap.c, since commit
("mm/migrate.c: rework migration_entry_wait() to not take a pageref").Make it static.
Link: https://lkml.kernel.org/r/20220914021738.3228011-1-sunke@kylinos.cn
Signed-off-by: Ke Sun
Reported-by: k2ci
Signed-off-by: Andrew Morton -
The memory-notify-based approach aims to handle meory-less nodes, however,
it just adds the complexity of code as pointed by David in thread [1].
The handling of memory-less nodes is introduced by commit 4faf8d950ec4
("hugetlb: handle memory hot-plug events"). >From its commit message, we
cannot find any necessity of handling this case. So, we can simply
register/unregister sysfs entries in register_node/unregister_node to
simlify the code.BTW, hotplug callback added because in hugetlb_register_all_nodes() we
register sysfs nodes only for N_MEMORY nodes, seeing commit 9b5e5d0fdc91,
which said it was a preparation for handling memory-less nodes via memory
hotplug. Since we want to remove memory hotplug, so make sure we only
register per-node sysfs for online (N_ONLINE) nodes in
hugetlb_register_all_nodes().https://lore.kernel.org/linux-mm/60933ffc-b850-976c-78a0-0ee6e0ea9ef0@redhat.com/ [1]
Link: https://lkml.kernel.org/r/20220914072603.60293-3-songmuchun@bytedance.com
Suggested-by: David Hildenbrand
Signed-off-by: Muchun Song
Acked-by: David Hildenbrand
Cc: Andi Kleen
Cc: Greg Kroah-Hartman
Cc: Mike Kravetz
Cc: Oscar Salvador
Cc: Rafael J. Wysocki
Signed-off-by: Andrew Morton -
Patch series "simplify handling of per-node sysfs creation and removal",
v4.This patch (of 2):
The following commit offload per-node sysfs creation and removal to a
kworker and did not say why it is needed. And it also said "I don't know
that this is absolutely required". It seems like the author was not sure
as well. Since it only complicates the code, this patch will revert the
changes to simplify the code.39da08cb074c ("hugetlb: offload per node attribute registrations")
We could use memory hotplug notifier to do per-node sysfs creation and
removal instead of inserting those operations to node registration and
unregistration. Then, it can reduce the code coupling between node.c and
hugetlb.c. Also, it can simplify the code.Link: https://lkml.kernel.org/r/20220914072603.60293-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20220914072603.60293-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song
Acked-by: Mike Kravetz
Acked-by: David Hildenbrand
Cc: Andi Kleen
Cc: Greg Kroah-Hartman
Cc: Muchun Song
Cc: Oscar Salvador
Cc: Rafael J. Wysocki
Signed-off-by: Andrew Morton -
Replace the simple calculation with PAGE_ALIGN.
Link: https://lkml.kernel.org/r/20220913015505.1998958-1-zuoze1@huawei.com
Signed-off-by: ze zuo
Reviewed-by: Muchun Song
Signed-off-by: Andrew Morton -
Cc: Catalin Marinas
Cc: ke.wang
Cc: Matthew Wilcox
Cc: Zhaoyang Huang
Signed-off-by: Andrew Morton -
The name "check_free_page()" provides no information regarding its return
value when the page is indeed found to be bad.Renaming it to "free_page_is_bad()" makes it clear that a `true' return
value means the page was bad.And make it return a bool, not an int.
[akpm@linux-foundation.org: don't use bool as int]
Cc: Catalin Marinas
Cc: ke.wang
Cc: Matthew Wilcox
Cc: Zhaoyang Huang
Signed-off-by: Andrew Morton -
Use kstrtobool which is more powerful to handle all kinds of parameters
like 'Yy1Nn0' or [oO][NnFf] for "on" and "off".Link: https://lkml.kernel.org/r/20220913071358.1812206-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin
Acked-by: Michal Hocko
Cc: Johannes Weiner
Cc: Jonathan Corbet
Cc: Kefeng Wang
Cc: Muchun Song
Cc: Roman Gushchin
Cc: Shakeel Butt
Signed-off-by: Andrew Morton -
When the 'kdamond_wait_activation()' function or 'after_sampling()' or
'after_aggregation()' DAMON callbacks return an error, it is unnecessary
to use bool 'done' to check if kdamond should be finished. This commit
simplifies the kdamond stop mechanism by removing 'done' and break the
while loop directly in the cases.Link: https://lkml.kernel.org/r/1663060287-30201-4-git-send-email-kaixuxia@tencent.com
Signed-off-by: Kaixu Xia
Reviewed-by: SeongJae Park
Signed-off-by: Andrew Morton -
We can initialize the variable 'pid' with '-1' in pid_show() to simplify
the variable assignment operation and make the code more readable.Link: https://lkml.kernel.org/r/1663060287-30201-3-git-send-email-kaixuxia@tencent.com
Signed-off-by: Kaixu Xia
Reviewed-by: SeongJae Park
Signed-off-by: Andrew Morton -
Patch series "mm/damon: code simplifications and cleanups".
This patchset contains some code simplifications and cleanups for DAMON.
This patch (of 4):
The parameter 'struct damon_ctx *ctx' isn't used in the functions
__damon_{p,v}a_prepare_access_check(), so we can remove it and simplify
the parameter passing.Link: https://lkml.kernel.org/r/1663060287-30201-1-git-send-email-kaixuxia@tencent.com
Link: https://lkml.kernel.org/r/1663060287-30201-2-git-send-email-kaixuxia@tencent.com
Signed-off-by: Kaixu Xia
Reviewed-by: SeongJae Park
Signed-off-by: Andrew Morton -
damon_lru_sort_new_{hot,cold}_scheme() have quite a lot of duplicates.
This commit factors out the duplicate to a separate function and use it
for reducing the duplicate.Link: https://lkml.kernel.org/r/20220913174449.50645-23-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_LRU_SORT to generate the module parameters for
DAMOS watermarks using the generator macro to simplify the code and reduce
duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-22-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_RECLAIM to generate the module parameters for
DAMOS quotas using the generator macro to simplify the code and reduce
duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-21-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_LRU_SORT have module parameters for DAMOS time quota only but size
quota. This commit implements a macro for generating the module
parameters so that we can reuse later.Link: https://lkml.kernel.org/r/20220913174449.50645-20-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_RECLAIM and DAMON_LRU_SORT have module parameters for DAMOS quotas
that having same names. This commit implements a macro for generating
such module parameters so that we can reuse later.Link: https://lkml.kernel.org/r/20220913174449.50645-19-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_LRU_SORT to generate the module parameters for
DAMOS statistics using the generator macro to simplify the code and reduce
duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-18-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_RECLAIM to generate the module parameters for
DAMOS statistics using the generator macro to simplify the code and
reduce duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-17-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_RECLAIM and DAMON_LRU_SORT have module parameters for DAMOS
statistics that having same names. This commit implements a macro for
generating such module parameters so that we can reuse later.Link: https://lkml.kernel.org/r/20220913174449.50645-16-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_RECLAIM to generate the module parameters for
DAMOS watermarks using the generator macro to simplify the code and reduce
duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-15-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_LRU_SORT to generate the module parameters for
DAMOS watermarks using the generator macro to simplify the code and reduce
duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-14-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_RECLAIM and DAMON_LRU_SORT have module parameters for watermarks
that having same names. This commit implements a macro for generating
such module parameters so that we can reuse later.Link: https://lkml.kernel.org/r/20220913174449.50645-13-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_RECLAIM to generate the module parameters for
DAMON monitoring attributes using the generator macro to simplify the code
and reduce duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-12-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
This commit makes DAMON_LRU_SORT to generate the module parameters for
DAMON monitoring attributes using the generator macro to simplify the code
and reduce duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-11-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_RECLAIM and DAMON_LRU_SORT have module parameters for monitoring
attributes that having same names. This commot implements a macro for
generating such module parameters so that we can reuse later.Link: https://lkml.kernel.org/r/20220913174449.50645-10-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_LRU_SORT receives monitoring attributes by parameters one by one to
separate variables, and then combines those into 'struct damon_attrs'.
This commit makes the module directly stores the parameter values to a
static 'struct damon_attrs' variable and use it to simplify the code.Link: https://lkml.kernel.org/r/20220913174449.50645-9-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON_RECLAIM receives monitoring attributes by parameters one by one to
separate variables, and then combine those into 'struct damon_attrs'.
This commit makes the module directly stores the parameter values to a
static 'struct damon_attrs' variable and use it to simplify the code.Link: https://lkml.kernel.org/r/20220913174449.50645-8-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
Number of parameters for 'damon_set_attrs()' is six. As it could be
confusing and verbose, this commit reduces the number by receiving single
pointer to a 'struct damon_attrs'.Link: https://lkml.kernel.org/r/20220913174449.50645-7-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
DAMON monitoring attributes are directly defined as fields of 'struct
damon_ctx'. This makes 'struct damon_ctx' a little long and complicated.
This commit defines and uses a struct, 'struct damon_attrs', which is
dedicated for only the monitoring attributes to make the purpose of the
five values clearer and simplify 'struct damon_ctx'.Link: https://lkml.kernel.org/r/20220913174449.50645-6-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
The 'struct damos' creation function, 'damon_new_scheme()', does
initialization of private fileds of 'struct damos_quota' in it. As its
verbose and makes the function unnecessarily long, this commit factors it
out to separate function.Link: https://lkml.kernel.org/r/20220913174449.50645-5-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
The function for new 'struct damos' creation, 'damon_new_scheme()', copies
each field of the struct one by one, though it could simply copied via
struct to struct. This commit replaces the unnecessarily verbose
field-to-field copies with struct-to-struct copies to make code simple and
short.Link: https://lkml.kernel.org/r/20220913174449.50645-4-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
The bodies of damon_pa_{mark_accessed,deactivate_pages}() contains
duplicates. This commit factors out the common part to a separate
function and removes the duplicates.Link: https://lkml.kernel.org/r/20220913174449.50645-3-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
Patch series "mm/damon: cleanup code".
DAMON code was not so clean from the beginning, but it has been too much
nowadays, especially due to the duplicates in DAMON_RECLAIM and
DAMON_LRU_SORT. This patchset cleans some of the mess.This patch (of 22):
The 'switch-case' statement in 'damon_va_apply_scheme()' function provides
a 'case' for every supported DAMOS action while all not-yet-supported
DAMOS actions fall through the 'default' case, and comment it so that
people can easily know which actions are supported. Its counterpart in
'paddr', 'damon_pa_apply_scheme()', however, doesn't. This commit makes
the 'paddr' side function follows the pattern of 'vaddr' for better
readability and consistency.Link: https://lkml.kernel.org/r/20220913174449.50645-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20220913174449.50645-2-sj@kernel.org
Signed-off-by: SeongJae Park
Signed-off-by: Andrew Morton -
In damon_lru_sort_apply_parameters(), we can use damon_set_schemes() to
replace the way of creating the first 'scheme' in original code, this
makes the code look cleaner.Link: https://lkml.kernel.org/r/20220911005917.835-1-xhao@linux.alibaba.com
Signed-off-by: Xin Hao
Reviewed-by: SeongJae Park
Signed-off-by: Andrew Morton -
Several trivial fixups (that I should have spotted during review).
Link: https://lkml.kernel.org/r/20220914052033.838050-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky
Signed-off-by: Andrew Morton -
zram_table_entry::flags stores object size in the lower bits and zram
pageflags in the upper bits. However, for some reason, we use 24 lower
bits, while maximum zram object size is PAGE_SIZE, which requires
PAGE_SHIFT bits (up to 16 on arm64). This wastes 24 - PAGE_SHIFT bits
that we can use for additional zram pageflags instead.Also add a BUILD_BUG_ON() to alert us should we run out of bits in
zram_table_entry::flags.Link: https://lkml.kernel.org/r/20220912152744.527438-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky
Reviewed-by: Brian Geffon
Acked-by: Minchan Kim
Cc: Nitin Gupta
Signed-off-by: Andrew Morton
