From: Andrew Morton <akpm@linux-foundation•org>
To: Suren Baghdasaryan <surenb@google•com>
Cc: michel@lespinasse•org, joelaf@google•com, songliubraving@fb•com,
mhocko@suse•com, leewalsh@google•com, david@redhat•com,
peterz@infradead•org, bigeasy@linutronix•de, peterx@redhat•com,
dhowells@redhat•com, linux-mm@kvack•org, edumazet@google•com,
jglisse@google•com, punit.agrawal@bytedance•com, will@kernel•org,
arjunroy@google•com, dave@stgolabs•net, minchan@google•com,
x86@kernel•org, hughd@google•com, willy@infradead•org,
gurua@google•com, mingo@redhat•com,
linux-arm-kernel@lists•infradead.org, rientjes@google•com,
axelrasmussen@google•com, kernel-team@android•com,
soheil@google•com, paulmck@kernel•org, jannh@google•com,
liam.howlett@oracle•com, shakeelb@google•com, luto@kernel•org,
gthelen@google•com, ldufour@linux•ibm.com, vbabka@suse•cz,
posk@google•com, lstoakes@gmail•com, peterjung1337@gmail•com,
linuxppc-dev@lists•ozlabs.org, kent.overstreet@linux•dev,
linux-kernel@vger•kernel.org, hannes@cmpxchg•org,
tatashin@google•com, mgorman@techsingularity•net,
rppt@kernel•org
Subject: Re: [PATCH v2 00/33] Per-VMA locks
Date: Fri, 27 Jan 2023 14:51:38 -0800 [thread overview]
Message-ID: <20230127145138.8cc44bf00ebf289dffec0975@linux-foundation.org> (raw)
In-Reply-To: <20230127194110.533103-1-surenb@google.com>
On Fri, 27 Jan 2023 11:40:37 -0800 Suren Baghdasaryan <surenb@google•com> wrote:
> Per-vma locks idea that was discussed during SPF [1] discussion at LSF/MM
> last year [2], which concluded with suggestion that “a reader/writer
> semaphore could be put into the VMA itself; that would have the effect of
> using the VMA as a sort of range lock. There would still be contention at
> the VMA level, but it would be an improvement.” This patchset implements
> this suggested approach.
I think I'll await reviewer/tester input for a while.
> The patchset implements per-VMA locking only for anonymous pages which
> are not in swap and avoids userfaultfs as their implementation is more
> complex. Additional support for file-back page faults, swapped and user
> pages can be added incrementally.
This is a significant risk. How can we be confident that these as yet
unimplemented parts are implementable and that the result will be good?
next prev parent reply other threads:[~2023-01-27 22:52 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-27 19:40 [PATCH v2 00/33] Per-VMA locks Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 01/33] maple_tree: Be more cautious about dead nodes Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 02/33] maple_tree: Detect dead nodes in mas_start() Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 03/33] maple_tree: Fix freeing of nodes in rcu mode Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 04/33] maple_tree: remove extra smp_wmb() from mas_dead_leaves() Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 05/33] maple_tree: Fix write memory barrier of nodes once dead for RCU mode Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 06/33] maple_tree: Add smp_rmb() to dead node detection Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 07/33] mm: Enable maple tree RCU mode by default Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 08/33] mm: introduce CONFIG_PER_VMA_LOCK Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 09/33] mm: rcu safe VMA freeing Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 10/33] mm: move mmap_lock assert function definitions Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 11/33] mm: add per-VMA lock and helper functions to control it Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 12/33] mm: mark VMA as being written when changing vm_flags Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 13/33] mm/mmap: move VMA locking before vma_adjust_trans_huge call Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 14/33] mm/khugepaged: write-lock VMA while collapsing a huge page Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 15/33] mm/mmap: write-lock VMAs before merging, splitting or expanding them Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 16/33] mm/mmap: write-lock VMA before shrinking or expanding it Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 17/33] mm/mremap: write-lock VMA while remapping it to a new address range Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 18/33] mm: write-lock VMAs before removing them from VMA tree Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 19/33] mm: conditionally write-lock VMA in free_pgtables Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 20/33] mm/mmap: write-lock adjacent VMAs if they can grow into unmapped area Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 21/33] kernel/fork: assert no VMA readers during its destruction Suren Baghdasaryan
2023-01-27 19:40 ` [PATCH v2 22/33] mm/mmap: prevent pagefault handler from racing with mmu_notifier registration Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 23/33] mm: introduce lock_vma_under_rcu to be used from arch-specific code Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 24/33] mm: fall back to mmap_lock if vma->anon_vma is not yet set Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 25/33] mm: add FAULT_FLAG_VMA_LOCK flag Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 26/33] mm: prevent do_swap_page from handling page faults under VMA lock Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 27/33] mm: prevent userfaults to be handled under per-vma lock Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 28/33] mm: introduce per-VMA lock statistics Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 29/33] x86/mm: try VMA lock-based page fault handling first Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 30/33] arm64/mm: " Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 31/33] powerc/mm: " Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 32/33] mm/mmap: free vm_area_struct without call_rcu in exit_mmap Suren Baghdasaryan
2023-01-27 19:41 ` [PATCH v2 33/33] mm: separate vma->lock from vm_area_struct Suren Baghdasaryan
2023-01-27 22:51 ` Andrew Morton [this message]
2023-01-27 23:26 ` [PATCH v2 00/33] Per-VMA locks Matthew Wilcox
2023-01-28 0:00 ` Suren Baghdasaryan
2023-02-14 16:47 ` Suren Baghdasaryan
2023-02-15 17:32 ` [External] " Punit Agrawal
2023-02-15 17:39 ` Suren Baghdasaryan
2023-02-28 12:06 ` Punit Agrawal
2023-02-28 18:08 ` Suren Baghdasaryan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230127145138.8cc44bf00ebf289dffec0975@linux-foundation.org \
--to=akpm@linux-foundation$(echo .)org \
--cc=arjunroy@google$(echo .)com \
--cc=axelrasmussen@google$(echo .)com \
--cc=bigeasy@linutronix$(echo .)de \
--cc=dave@stgolabs$(echo .)net \
--cc=david@redhat$(echo .)com \
--cc=dhowells@redhat$(echo .)com \
--cc=edumazet@google$(echo .)com \
--cc=gthelen@google$(echo .)com \
--cc=gurua@google$(echo .)com \
--cc=hannes@cmpxchg$(echo .)org \
--cc=hughd@google$(echo .)com \
--cc=jannh@google$(echo .)com \
--cc=jglisse@google$(echo .)com \
--cc=joelaf@google$(echo .)com \
--cc=kent.overstreet@linux$(echo .)dev \
--cc=kernel-team@android$(echo .)com \
--cc=ldufour@linux$(echo .)ibm.com \
--cc=leewalsh@google$(echo .)com \
--cc=liam.howlett@oracle$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-mm@kvack$(echo .)org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=lstoakes@gmail$(echo .)com \
--cc=luto@kernel$(echo .)org \
--cc=mgorman@techsingularity$(echo .)net \
--cc=mhocko@suse$(echo .)com \
--cc=michel@lespinasse$(echo .)org \
--cc=minchan@google$(echo .)com \
--cc=mingo@redhat$(echo .)com \
--cc=paulmck@kernel$(echo .)org \
--cc=peterjung1337@gmail$(echo .)com \
--cc=peterx@redhat$(echo .)com \
--cc=peterz@infradead$(echo .)org \
--cc=posk@google$(echo .)com \
--cc=punit.agrawal@bytedance$(echo .)com \
--cc=rientjes@google$(echo .)com \
--cc=rppt@kernel$(echo .)org \
--cc=shakeelb@google$(echo .)com \
--cc=soheil@google$(echo .)com \
--cc=songliubraving@fb$(echo .)com \
--cc=surenb@google$(echo .)com \
--cc=tatashin@google$(echo .)com \
--cc=vbabka@suse$(echo .)cz \
--cc=will@kernel$(echo .)org \
--cc=willy@infradead$(echo .)org \
--cc=x86@kernel$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox