The sort function has the inbuilt reversal option. We can use it to save
some time.
Link: https://lkml.kernel.org/r/20230106091319.3824-1-apantykhin@gmail.com
Signed-off-by: Alexander Pantyukhin <apantykhin@gmail.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This command provides a way to traverse the entire page hierarchy by a
given virtual address on x86. In addition to qemu's commands info
tlb/info mem it provides the complete information about the paging
structure for an arbitrary virtual address. It supports 4KB/2MB/1GB and 5
level paging.
Here is an example output for 2MB success translation:
(gdb) translate-vm address
cr3:
cr3 binary data 0x1085be003
next entry physical address 0x1085be000
---
bit 3 page level write through False
bit 4 page level cache disabled False
level 4:
entry address 0xffff8881085be7f8
page entry binary data 0x800000010ac83067
next entry physical address 0x10ac83000
---
bit 0 entry present True
bit 1 read/write access allowed True
bit 2 user access allowed True
bit 3 page level write through False
bit 4 page level cache disabled False
bit 5 entry has been accessed True
bit 7 page size False
bit 11 restart to ordinary False
bit 63 execute disable True
level 3:
entry address 0xffff88810ac83a48
page entry binary data 0x101af7067
next entry physical address 0x101af7000
---
bit 0 entry present True
bit 1 read/write access allowed True
bit 2 user access allowed True
bit 3 page level write through False
bit 4 page level cache disabled False
bit 5 entry has been accessed True
bit 7 page size False
bit 11 restart to ordinary False
bit 63 execute disable False
level 2:
entry address 0xffff888101af7368
page entry binary data 0x80000001634008e7
page size 2MB
page physical address 0x163400000
---
bit 0 entry present True
bit 1 read/write access allowed True
bit 2 user access allowed True
bit 3 page level write through False
bit 4 page level cache disabled False
bit 5 entry has been accessed True
bit 7 page size True
bit 6 page dirty True
bit 8 global translation False
bit 11 restart to ordinary True
bit 12 pat False
bits (59, 62) protection key 0
bit 63 execute disable True
[dmitrii.bundin.a@gmail.com: add SPDX line, other tweaks]
Link: https://lkml.kernel.org/r/20230113175151.22278-1-dmitrii.bundin.a@gmail.com
[akpm@linux-foundation.org: s/physicall/physical/]
Link: https://lkml.kernel.org/r/20230102171014.31408-1-dmitrii.bundin.a@gmail.com
Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Acked by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When destroying a kthread worker warn if there are still some pending
delayed works. This indicates that the caller should clear all pending
delayed works before destroying the kthread worker.
Link: https://lkml.kernel.org/r/20230104144230.938521-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
/proc/cmdline is never removed, mark is as permanent for slightly faster
open and close.
Link: https://lkml.kernel.org/r/Y66xAveh2yUsP7m9@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It was suggested by Fabio that kunmap() be marked deprecated in
checkpatch.[1] This did not seem necessary until an invalid conversion of
kmap_local_page() appeared in mainline.[2][3] The introduction of this bug
would have been flagged with kunmap() being marked deprecated.
Add kunmap() and kunmap_atomic() to checkpatch to help prevent further
confusion.
[1] https://lore.kernel.org/all/1884934.6tgchFWduM@suse/
[2] d406d26745 ("cifs: skip alloc when request has no pages")
[3] https://lore.kernel.org/r/20221229-cifs-kmap-v1-1-c70d0e9a53eb@intel.com
Link: https://lkml.kernel.org/r/20221229-kmap-checkpatch-v2-1-919fc4d4e3c2@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Suggested-by: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "spelling: Fix some trivial typos".
Seems like permitted has two t's :), Lets add that to spellings to help
others.
This patch (of 3):
Add another common typo. Noticed when I sent a patch with the typo and
in kvm and of.
[ribalda@chromium.org: fix trivial typo]
Link: https://lkml.kernel.org/r/20221220-permited-v1-2-52ea9857fa61@chromium.org
Link: https://lkml.kernel.org/r/20221220-permited-v1-1-52ea9857fa61@chromium.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Variables are assigned first and then used. Initialization is not
required.
[akpm@linux-foundation.org: give hfsplus_listxattr:key_len narrower scope]
Link: https://lkml.kernel.org/r/20221221032119.10037-1-xupengfei@nfschina.com
Signed-off-by: XU pengfei <xupengfei@nfschina.com>
Reviewed-by: Andrew Morton <akpm@linux-foudation.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When working on SoC bring-up, (a full) userspace may not be available,
making it hard to benchmark the CPU performance of the system under
development. Still, one may want to have a rough idea of the (relative)
performance of one or more CPU cores, especially when working on e.g. the
clock driver that controls the CPU core clock(s).
Hence make the classical Dhrystone 2.1 benchmark available as a Linux
kernel test module, based on[1].
When built-in, this benchmark can be run without any userspace present.
Parallel runs (run on multiple CPU cores) are supported, just kick the
"run" file multiple times.
Note that the actual figures depend on the configuration options that
control compiler optimization (e.g. CONFIG_CC_OPTIMIZE_FOR_SIZE vs.
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE), and on the compiler options used when
building the kernel in general. Hence numbers may differ from those
obtained by running similar benchmarks in userspace.
[1] https://github.com/qris/dhrystone-deb.git
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/4d07ad990740a5f1e426ce4566fb514f60ec9bdd.1670509558.git.geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
[geert+renesas@glider.be: fix uninitialized use of ret]
Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2212190857310.137329@ramsan.of.borg
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The percpu interface is supposed to be preempt and irq safe.
But:
The uniprocessor implementation of percpu_counter_add() is not irq safe:
if an interrupt happens during the +=, then the result is undefined.
Therefore: switch from preempt_disable() to local_irq_save().
This prevents interrupts from interrupting the +=, and as a side effect
prevents preemption.
Link: https://lkml.kernel.org/r/20221216150441.200533-2-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: "Sun, Jiebin" <jiebin.sun@intel.com>
Cc: <1vier1@web.de>
Cc: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "various irq handling fixes/docu updates".
If an interrupt happens between __this_cpu_read(*fbc->counters) and
this_cpu_add(*fbc->counters, amount), and that interrupt modifies the
per_cpu_counter, then the this_cpu_add() after the interrupt returns may
under/overflow.
Link: https://lkml.kernel.org/r/20221216150155.200389-1-manfred@colorfullife.com
Link: https://lkml.kernel.org/r/20221216150441.200533-1-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: "Sun, Jiebin" <jiebin.sun@intel.com>
Cc: <1vier1@web.de>
Cc: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a section about the requirements of the error injectable functions and
the type of errors.
Since this section must be read before using ALLOW_ERROR_INJECTION()
macro, that section is referred from the comment of the macro too.
Link: https://lkml.kernel.org/r/167081321427.387937.15475445689482551048.stgit@devnote3
Link: https://lore.kernel.org/all/20221211115218.2e6e289bb85f8cf53c11aa97@kernel.org/T/#u
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Florent Revest <revest@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "error-injection: Clarify the requirements of error
injectable functions".
Patches for clarifying the requirement of error injectable functions and
to remove the confusing EI_ETYPE_NONE.
This patch (of 2):
Since the EI_ETYPE_NONE is confusing type, replace it with appropriate
errno. The EI_ETYPE_NONE has been introduced for a dummy (error) value,
but it can mislead people that they can use ALLOW_ERROR_INJECTION(func,
NONE). So remove it from the EI_ETYPE and use appropriate errno instead.
[akpm@linux-foundation.org: include/linux/error-injection.h needs errno.h]
Link: https://lkml.kernel.org/r/167081319306.387937.10079195394503045678.stgit@devnote3
Link: https://lkml.kernel.org/r/167081320421.387937.4259807348852421112.stgit@devnote3
Fixes: 663faf9f7b ("error-injection: Add injectable error types")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Florent Revest <revest@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
generic_ptr is a void * type and does not require a cast.
Link: https://lkml.kernel.org/r/20221213073633.3586-1-zeming@nfschina.com
Signed-off-by: Li zeming <zeming@nfschina.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The void * type pointer does not need to be cast and assigned to another
pointer.
Link: https://lkml.kernel.org/r/20221213074522.3738-1-zeming@nfschina.com
Signed-off-by: Li zeming <zeming@nfschina.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230202151554.2310273-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Fixes: d180e0a1be ("Drivers: hv: Create debugfs file with hyper-v balloon usage information")
Cc: stable <stable@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230202140918.2289522-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is just a conversion to the folio API. While there are some nods
towards supporting multi-page folios in here, the blocks array is still
sized for one page's worth of blocks, and there are other assumptions such
as the blocks_per_page variable.
[willy@infradead.org: fix accidentally-triggering WARN_ON_ONCE]
Link: https://lkml.kernel.org/r/Y9kuaBgXf9lKJ8b0@casper.infradead.org
Link: https://lkml.kernel.org/r/20230126201255.1681189-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Convert writepage_t to use a folio".
More folioisation. I split out the mpage work from everything else
because it completely dominated the patch, but some implementations I just
converted outright.
This patch (of 2):
We always write back an entire folio, but that's currently passed as the
head page. Convert all filesystems that use write_cache_pages() to expect
a folio instead of a page.
Link: https://lkml.kernel.org/r/20230126201255.1681189-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230126201255.1681189-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This is the equivalent of memcpy_from_page(). It differs in that it takes
the position in a file instead of offset in a folio, it accepts the total
number of bytes to be copied (instead of the number of bytes to be copied
from this folio) and it returns how many bytes were copied from the folio,
rather than making the caller calculate that and then checking if the
caller got it right.
[akpm@linux-foundation.org: fix typo in comment]
Link: https://lkml.kernel.org/r/20230126201552.1681588-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The ->rw_page method is a special purpose bypass of the usual bio handling
path that is limited to single-page reads and writes and synchronous which
causes a lot of extra code in the drivers, callers and the block layer.
The only remaining user is the MM swap code. Switch that swap code to
simply submit a single-vec on-stack bio an synchronously wait on it based
on a newly added QUEUE_FLAG_SYNCHRONOUS flag set by the drivers that
currently implement ->rw_page instead. While this touches one extra cache
line and executes extra code, it simplifies the block layer and drivers
and ensures that all feastures are properly supported by all drivers, e.g.
right now ->rw_page bypassed cgroup writeback entirely.
[akpm@linux-foundation.org: fix comment typo, per Dan]
Link: https://lkml.kernel.org/r/20230125133436.447864-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Split the block device case from swap_readpage into a separate helper,
following the abstraction for file based swap.
Link: https://lkml.kernel.org/r/20230125133436.447864-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Optimize the synchronous swap in case by using an on-stack bio instead of
allocating one using bio_alloc.
Link: https://lkml.kernel.org/r/20230125133436.447864-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Split the block device case from swap_readpage into a separate helper,
following the abstraction for file based swap and frontswap.
Link: https://lkml.kernel.org/r/20230125133436.447864-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
swap_readpage always returns 0, and no caller checks the return value.
[akpm@linux-foundation.org: fix void-returning swap_readpage() stub, per Keith]
Link: https://lkml.kernel.org/r/20230125133436.447864-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "remove ->rw_page".
This series removes the ->rw_page block_device_operation, which is an old
and clumsy attempt at a simple read/write fast path for the block layer.
It isn't actually used by the fastest block layer operations that we
support (polled I/O through io_uring), but only used by the mpage buffered
I/O helpers which are some of the slowest I/O we have and do not make any
difference there at all, and zram which is a block device abused to
duplicate the zram functionality.
Given that zram is heavily used we need to make sure there is a good
replacement for synchronous I/O, so this series adds a new flag for
drivers that complete I/O synchronously and uses that flag to use on-stack
bios and synchronous submission for them in the swap code.
This patch (of 7):
These are micro-optimizations for synchronous I/O, which do not matter
compared to all the other inefficiencies in the legacy buffer_head based
mpage code.
Link: https://lkml.kernel.org/r/20230125133436.447864-1-hch@lst.de
Link: https://lkml.kernel.org/r/20230125133436.447864-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move the VM_FLUSH_RESET_PERMS to the caller and rename the function to
better describe what it is doing.
Link: https://lkml.kernel.org/r/20230121071051.1143058-11-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
vunmap only needs to find and free the vmap_area and vm_strut, so open
code that there and merge the rest of the code into vfree.
Link: https://lkml.kernel.org/r/20230121071051.1143058-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All these checks apply to the free_vm_area interface as well, so move them
to the common routine.
Link: https://lkml.kernel.org/r/20230121071051.1143058-9-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the common helper to find and remove a vmap_area instead of open
coding it.
Link: https://lkml.kernel.org/r/20230121071051.1143058-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__remove_vm_area is the only part of va_remove_mappings that requires a
vmap_area. Move the call out to the caller and only pass the vm_struct to
va_remove_mappings.
Link: https://lkml.kernel.org/r/20230121071051.1143058-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This adds an extra, never taken, in_interrupt() branch, but will allow to
cut down the maze of vfree helpers.
Link: https://lkml.kernel.org/r/20230121071051.1143058-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move these two functions around a bit to avoid forward declarations.
Link: https://lkml.kernel.org/r/20230121071051.1143058-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fold __vfree_deferred into vfree_atomic, and call vfree_atomic early on
from vfree if called from interrupt context so that the extra low-level
helper can be avoided.
Link: https://lkml.kernel.org/r/20230121071051.1143058-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__vfree is a subset of vfree that just skips a few checks, and which is
only used by vfree and an error cleanup path. Fold __vfree into vfree and
switch the only other caller to call vfree() instead.
Link: https://lkml.kernel.org/r/20230121071051.1143058-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "cleanup vfree and vunmap".
This little series untangles the vfree and vunmap code path a bit.
This patch (of 10):
VM_FLUSH_RESET_PERMS is just for use with vmalloc as it is tied to freeing
the underlying pages.
Link: https://lkml.kernel.org/r/20230121071051.1143058-1-hch@lst.de
Link: https://lkml.kernel.org/r/20230121071051.1143058-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 7efc3b7261 ("mm/compaction: fix set skip in
fast_find_migrateblock") address an issue where a pageblock selected by
fast_find_migrateblock() was ignored. Unfortunately, the same fix
resulted in numerous reports of khugepaged or kcompactd stalling for long
periods of time or consuming 100% of CPU.
Tracing showed that there was a lot of rescanning between a small subset
of pageblocks because the conditions for marking the block skip are not
met. The scan is not reaching the end of the pageblock because enough
pages were isolated but none were migrated successfully. Eventually it
circles back to the same block.
Pageblock skip tracking tries to minimise both latency and excessive
scanning but tracking exactly when a block is fully scanned requires an
excessive amount of state. This patch forcibly rescans a pageblock when
all isolated pages fail to migrate even though it could be for transient
reasons such as page writeback or page dirty. This will sometimes migrate
too many pages but pageblocks will be marked skip and forward progress
will be made.
"Usemen" from the mmtests configuration
workload-usemem-stress-numa-compact was used to stress compaction. The
compaction trace events were recorded using a 6.2-rc5 kernel that includes
commit 7efc3b7261 and count of unique ranges were measured. The top 5
ranges were
3076 range=(0x10ca00-0x10cc00)
3076 range=(0x110a00-0x110c00)
3098 range=(0x13b600-0x13b800)
3104 range=(0x141c00-0x141e00)
11424 range=(0x11b600-0x11b800)
While this workload is very different than what the bugs reported, the
pattern of the same subset of blocks being repeatedly scanned is observed.
At one point, *only* the range range=(0x11b600 ~ 0x11b800) was scanned
for 2 seconds. 14 seconds passed between the first migration-related
event and the last.
With the series applied including this patch, the top 5 ranges were
1 range=(0x11607e-0x116200)
1 range=(0x116200-0x116278)
1 range=(0x116278-0x116400)
1 range=(0x116400-0x116424)
1 range=(0x116424-0x116600)
Only unique ranges were scanned and the time between the first
migration-related event was 0.11 milliseconds.
Link: https://lkml.kernel.org/r/20230125134434.18017-5-mgorman@techsingularity.net
Fixes: 7efc3b7261 ("mm/compaction: fix set skip in fast_find_migrateblock")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
cc->finish_pageblock is set when the current pageblock should be rescanned
but fast_find_migrateblock can select an alternative block. Disable
fast_find_migrateblock when the current pageblock scan should be
completed.
Link: https://lkml.kernel.org/r/20230125134434.18017-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If a page has been captured then draining is unnecssary so check first for
a captured page.
Link: https://lkml.kernel.org/r/20230125134434.18017-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Fix excessive CPU usage during compaction".
Commit 7efc3b7261 ("mm/compaction: fix set skip in fast_find_migrateblock")
fixed a problem where pageblocks found by fast_find_migrateblock() were
ignored. Unfortunately there were numerous bug reports complaining about high
CPU usage and massive stalls once 6.1 was released. Due to the severity,
the patch was reverted by Vlastimil as a short-term fix[1] to -stable.
The underlying problem for each of the bugs is suspected to be the
repeated scanning of the same pageblocks. This series should guarantee
forward progress even with commit 7efc3b7261. More information is in
the changelog for patch 4.
[1] http://lore.kernel.org/r/20230113173345.9692-1-vbabka@suse.cz
This patch (of 4):
The rescan field was not well named albeit accurate at the time. Rename
the field to finish_pageblock to indicate that the remainder of the
pageblock should be scanned regardless of COMPACT_CLUSTER_MAX. The intent
is that pageblocks with transient failures get marked for skipping to
avoid revisiting the same pageblock.
Link: https://lkml.kernel.org/r/20230125134434.18017-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The implementation of page_alloc poisoning sampling assumed that
tag_clear_highpage resets page tags for __GFP_ZEROTAGS allocations.
However, this is no longer the case since commit 70c248aca9 ("mm: kasan:
Skip unpoisoning of user pages").
This leads to kernel crashes when MTE-enabled userspace mappings are used
with Hardware Tag-Based KASAN enabled.
Reset page tags for __GFP_ZEROTAGS allocations in post_alloc_hook().
Also clarify and fix related comments.
[andreyknvl@google.com: update comment]
Link: https://lkml.kernel.org/r/5dbd866714b4839069e2d8469ac45b60953db290.1674592780.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/24ea20c1b19c2b4b56cf9f5b354915f8dbccfc77.1674592496.git.andreyknvl@google.com
Fixes: 44383cef54 ("kasan: allow sampling page_alloc allocations for HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Peter Collingbourne <pcc@google.com>
Tested-by: Peter Collingbourne <pcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
W=1 build with clangs complains:
mm/sparse.c:347:27: warning: unused function 'pgdat_to_phys' [-Wunused-function]
static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
^
1 warning generated.
pgdat_to_phys() is only used by functions defined when
CONFIG_MEMORY_HOTREMOVE=y.
Move pgdat_to_phys() under #ifdef CONFIG_MEMORY_HOTREMOVE
to make clang happy.
Link: https://lkml.kernel.org/r/20230121101151.1703292-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/all/202301210155.1E5zABb5-lkp@intel.com
Cc: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When allocating a high-order page, separate allocation timestamp is
recorded for each sub-page resulting in different timestamp values between
them.
This behavior is not consistent with the behavior when recording free
timestamp and caused confusion when analyzing memory dumps. Record single
timestamp for the entire allocation, aligning with the behavior for free
timestamps.
Link: https://lkml.kernel.org/r/20230121165054.520507-1-42.hyeyoo@gmail.com
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add documentation for memory_failure's per NUMA node sysfs entries
Link: https://lkml.kernel.org/r/20230120034622.2698268-4-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Right before memory_failure finishes its handling, accumulate poisoned
page's resolution counters to pglist_data's memory_failure_stats, so as to
update the corresponding sysfs entries.
Tested:
1) Start an application to allocate memory buffer chunks
2) Convert random memory buffer addresses to physical addresses
3) Inject memory errors using EINJ at chosen physical addresses
4) Access poisoned memory buffer and recover from SIGBUS
5) Check counter values under
/sys/devices/system/node/node*/memory_failure/*
Link: https://lkml.kernel.org/r/20230120034622.2698268-3-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Introduce per NUMA node memory error statistics", v2.
Background
==========
In the RFC for Kernel Support of Memory Error Detection [1], one advantage
of software-based scanning over hardware patrol scrubber is the ability to
make statistics visible to system administrators. The statistics include
2 categories:
* Memory error statistics, for example, how many memory error are
encountered, how many of them are recovered by the kernel. Note these
memory errors are non-fatal to kernel: during the machine check
exception (MCE) handling kernel already classified MCE's severity to be
unnecessary to panic (but either action required or optional).
* Scanner statistics, for example how many times the scanner have fully
scanned a NUMA node, how many errors are first detected by the scanner.
The memory error statistics are useful to userspace and actually not
specific to scanner detected memory errors, and are the focus of this
patchset.
Motivation
==========
Memory error stats are important to userspace but insufficient in kernel
today. Datacenter administrators can better monitor a machine's memory
health with the visible stats. For example, while memory errors are
inevitable on servers with 10+ TB memory, starting server maintenance when
there are only 1~2 recovered memory errors could be overreacting; in cloud
production environment maintenance usually means live migrate all the
workload running on the server and this usually causes nontrivial
disruption to the customer. Providing insight into the scope of memory
errors on a system helps to determine the appropriate follow-up action.
In addition, the kernel's existing memory error stats need to be
standardized so that userspace can reliably count on their usefulness.
Today kernel provides following memory error info to userspace, but they
are not sufficient or have disadvantages:
* HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total,
not per NUMA node stats though
* ras:memory_failure_event: only available after explicitly enabled
* /dev/mcelog provides many useful info about the MCEs, but doesn't
capture how memory_failure recovered memory MCEs
* kernel logs: userspace needs to process log text
Exposing memory error stats is also a good start for the in-kernel memory
error detector. Today the data source of memory error stats are either
direct memory error consumption, or hardware patrol scrubber detection
(either signaled as UCNA or SRAO). Once in-kernel memory scanner is
implemented, it will be the main source as it is usually configured to
scan memory DIMMs constantly and faster than hardware patrol scrubber.
How Implemented
===============
As Naoya pointed out [2], exposing memory error statistics to userspace is
useful independent of software or hardware scanner. Therefore we
implement the memory error statistics independent of the in-kernel memory
error detector. It exposes the following per NUMA node memory error
counters:
/sys/devices/system/node/node${X}/memory_failure/total
/sys/devices/system/node/node${X}/memory_failure/recovered
/sys/devices/system/node/node${X}/memory_failure/ignored
/sys/devices/system/node/node${X}/memory_failure/failed
/sys/devices/system/node/node${X}/memory_failure/delayed
These counters describe how many raw pages are poisoned and after the
attempted recoveries by the kernel, their resolutions: how many are
recovered, ignored, failed, or delayed respectively. This approach can be
easier to extend for future use cases than /proc/meminfo, trace event, and
log. The following math holds for the statistics:
* total = recovered + ignored + failed + delayed
These memory error stats are reset during machine boot.
The 1st commit introduces these sysfs entries. The 2nd commit populates
memory error stats every time memory_failure attempts memory error
recovery. The 3rd commit adds documentations for introduced stats.
[1] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#mc22959244f5388891c523882e61163c6e4d703af
[2] https://lore.kernel.org/linux-mm/7E670362-C29E-4626-B546-26530D54F937@gmail.com/T/#m52d8d7a333d8536bd7ce74253298858b1c0c0ac6
This patch (of 3):
Today kernel provides following memory error info to userspace, but each
has its own disadvantage
* HardwareCorrupted in /proc/meminfo: number of bytes poisoned in total,
not per NUMA node stats though
* ras:memory_failure_event: only available after explicitly enabled
* /dev/mcelog provides many useful info about the MCEs, but
doesn't capture how memory_failure recovered memory MCEs
* kernel logs: userspace needs to process log text
Exposes per NUMA node memory error stats as sysfs entries:
/sys/devices/system/node/node${X}/memory_failure/total
/sys/devices/system/node/node${X}/memory_failure/recovered
/sys/devices/system/node/node${X}/memory_failure/ignored
/sys/devices/system/node/node${X}/memory_failure/failed
/sys/devices/system/node/node${X}/memory_failure/delayed
These counters describe how many raw pages are poisoned and after the
attempted recoveries by the kernel, their resolutions: how many are
recovered, ignored, failed, or delayed respectively. The following math
holds for the statistics:
* total = recovered + ignored + failed + delayed
Link: https://lkml.kernel.org/r/20230120034622.2698268-1-jiaqiyan@google.com
Link: https://lkml.kernel.org/r/20230120034622.2698268-2-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexander Pantyukhin