From: Michel Lespinasse <michel@lespinasse.org>
To: Linux-MM <linux-mm@kvack.org>,
Linux-Kernel <linux-kernel@vger.kernel.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
Michal Hocko <mhocko@suse.com>,
Matthew Wilcox <willy@infradead.org>,
Rik van Riel <riel@surriel.com>,
Paul McKenney <paulmck@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Suren Baghdasaryan <surenb@google.com>,
Joel Fernandes <joelaf@google.com>,
Andy Lutomirski <luto@kernel.org>,
Michel Lespinasse <michel@lespinasse.org>
Subject: [PATCH 06/29] mm: introduce CONFIG_SPECULATIVE_PAGE_FAULT
Date: Fri, 30 Apr 2021 12:52:07 -0700 [thread overview]
Message-ID: <20210430195232.30491-7-michel@lespinasse.org> (raw)
In-Reply-To: <20210430195232.30491-1-michel@lespinasse.org>
This configuration variable will be used to build the code needed to
handle speculative page fault.
This is enabled by default on supported architectures with SMP and MMU set.
The architecture support is needed since the speculative page fault handler
is called from the architecture's page faulting code, and some code has to
be added there to try speculative fault handling first.
Signed-off-by: Michel Lespinasse <michel@lespinasse.org>
---
mm/Kconfig | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/mm/Kconfig b/mm/Kconfig
index 24c045b24b95..322bda319dea 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -872,4 +872,26 @@ config MAPPING_DIRTY_HELPERS
config KMAP_LOCAL
bool
+config ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT
+ def_bool n
+
+config SPECULATIVE_PAGE_FAULT
+ bool "Speculative page faults"
+ default y
+ depends on ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT && MMU && SMP
+ help
+ Try to handle user space page faults without holding the mmap lock.
+
+ Instead of blocking writers through the use of mmap lock,
+ the page fault handler merely verifies, at the end of the page
+ fault, that no writers have been running concurrently with it.
+
+ In high concurrency situations, the speculative fault handler
+ gains a throughput advantage by avoiding having to update the
+ mmap lock reader count.
+
+ If the check fails due to a concurrent writer, or due to hitting
+ an unsupported case, the fault handler falls back to classical
+ processing using the mmap read lock.
+
endmenu
--
2.20.1
next prev parent reply other threads:[~2021-04-30 19:52 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 19:52 [PATCH 00/29] Speculative page faults (anon vmas only) Michel Lespinasse
2021-04-30 19:52 ` [PATCH 01/29] mm: export dump_mm Michel Lespinasse
2021-04-30 19:52 ` [PATCH 02/29] mmap locking API: mmap_lock_is_contended returns a bool Michel Lespinasse
2021-04-30 19:52 ` [PATCH 03/29] mmap locking API: name the return values Michel Lespinasse
2021-04-30 19:52 ` [PATCH 04/29] do_anonymous_page: use update_mmu_tlb() Michel Lespinasse
2021-06-10 0:38 ` Suren Baghdasaryan
2021-06-10 0:38 ` Suren Baghdasaryan
2021-04-30 19:52 ` [PATCH 05/29] do_anonymous_page: reduce code duplication Michel Lespinasse
2021-04-30 19:52 ` Michel Lespinasse [this message]
2021-04-30 19:52 ` [PATCH 07/29] x86/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2021-04-30 19:52 ` [PATCH 08/29] mm: add FAULT_FLAG_SPECULATIVE flag Michel Lespinasse
2021-06-10 0:58 ` Suren Baghdasaryan
2021-06-10 0:58 ` Suren Baghdasaryan
2021-04-30 19:52 ` [PATCH 09/29] mm: add do_handle_mm_fault() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 10/29] mm: add per-mm mmap sequence counter for speculative page fault handling Michel Lespinasse
2021-04-30 19:52 ` [PATCH 11/29] mm: rcu safe vma freeing Michel Lespinasse
2021-04-30 19:52 ` [PATCH 12/29] x86/mm: attempt speculative mm faults first Michel Lespinasse
2021-04-30 19:52 ` [PATCH 13/29] mm: add speculative_page_walk_begin() and speculative_page_walk_end() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 14/29] mm: refactor __handle_mm_fault() / handle_pte_fault() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 15/29] mm: implement speculative handling in __handle_mm_fault() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 16/29] mm: add pte_map_lock() and pte_spinlock() Michel Lespinasse
2021-04-30 23:33 ` kernel test robot
2021-04-30 23:33 ` kernel test robot
2021-04-30 23:45 ` kernel test robot
2021-04-30 23:45 ` kernel test robot
2021-04-30 19:52 ` [PATCH 17/29] mm: implement speculative handling in do_anonymous_page() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 18/29] mm: enable speculative fault handling through do_anonymous_page() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 19/29] mm: implement speculative handling in do_numa_page() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 20/29] mm: enable speculative fault " Michel Lespinasse
2021-04-30 19:52 ` [PATCH 21/29] mm: implement speculative handling in wp_page_copy() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 22/29] mm: implement and enable speculative fault handling in handle_pte_fault() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 23/29] mm: implement speculative handling in do_swap_page() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 24/29] mm: enable speculative fault handling through do_swap_page() Michel Lespinasse
2021-04-30 19:52 ` [PATCH 25/29] mm: disable speculative faults for single threaded user space Michel Lespinasse
2021-04-30 19:52 ` [PATCH 26/29] mm: disable rcu safe vma freeing " Michel Lespinasse
2021-04-30 19:52 ` [PATCH 27/29] mm: anon spf statistics Michel Lespinasse
2021-04-30 22:52 ` kernel test robot
2021-04-30 22:52 ` kernel test robot
2021-04-30 19:52 ` [PATCH 28/29] arm64/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2021-04-30 19:52 ` [PATCH 29/29] arm64/mm: attempt speculative mm faults first Michel Lespinasse
2021-04-30 19:52 ` [PATCH 30/31] powerpc/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT Michel Lespinasse
2021-04-30 19:52 ` [PATCH 31/31] powerpc/mm: attempt speculative mm faults first Michel Lespinasse
2021-04-30 22:46 ` [PATCH 00/29] Speculative page faults (anon vmas only) Michel Lespinasse
2021-05-03 18:11 ` Michel Lespinasse
2021-05-17 17:57 ` Paul E. McKenney
2021-05-20 22:10 ` Suren Baghdasaryan
2021-05-20 22:10 ` Suren Baghdasaryan
2021-05-20 23:08 ` Paul E. McKenney
2021-06-01 7:41 ` Michel Lespinasse
2021-06-01 20:18 ` Paul E. McKenney
2021-06-01 20:23 ` Paul E. McKenney
2021-06-14 7:04 ` Michel Lespinasse
2021-05-01 19:56 ` Theodore Ts'o
2021-05-01 21:19 ` Michel Lespinasse
2021-06-17 13:46 ` David Hildenbrand
2021-07-09 10:41 ` David Hildenbrand
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=20210430195232.30491-7-michel@lespinasse.org \
--to=michel@lespinasse.org \
--cc=akpm@linux-foundation.org \
--cc=joelaf@google.com \
--cc=ldufour@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mhocko@suse.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=riel@surriel.com \
--cc=surenb@google.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.