Commit Graph

2835 Commits

Author SHA1 Message Date
John Baldwin
e42b096439 Document EINTEGRITY errors for many system calls.
EINTEGRITY was previously documented as a UFS-specific error for
mount(2).  This documents EINTEGRITY as a filesystem-independent error
that may be reported by the backing store of a filesystem.

While here, document EIO as a filesystem-independent error for both
mount(2) and posix_fadvise(2).  EIO was previously only documented for
UFS for mount(2).

Reviewed by:	mckusick
Suggested by:	mckusick
MFC after:	2 weeks
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D24168
2020-03-30 21:44:00 +00:00
John Baldwin
c034143269 Refactor driver and consumer interfaces for OCF (in-kernel crypto).
- The linked list of cryptoini structures used in session
  initialization is replaced with a new flat structure: struct
  crypto_session_params.  This session includes a new mode to define
  how the other fields should be interpreted.  Available modes
  include:

  - COMPRESS (for compression/decompression)
  - CIPHER (for simply encryption/decryption)
  - DIGEST (computing and verifying digests)
  - AEAD (combined auth and encryption such as AES-GCM and AES-CCM)
  - ETA (combined auth and encryption using encrypt-then-authenticate)

  Additional modes could be added in the future (e.g. if we wanted to
  support TLS MtE for AES-CBC in the kernel we could add a new mode
  for that.  TLS modes might also affect how AAD is interpreted, etc.)

  The flat structure also includes the key lengths and algorithms as
  before.  However, code doesn't have to walk the linked list and
  switch on the algorithm to determine which key is the auth key vs
  encryption key.  The 'csp_auth_*' fields are always used for auth
  keys and settings and 'csp_cipher_*' for cipher.  (Compression
  algorithms are stored in csp_cipher_alg.)

- Drivers no longer register a list of supported algorithms.  This
  doesn't quite work when you factor in modes (e.g. a driver might
  support both AES-CBC and SHA2-256-HMAC separately but not combined
  for ETA).  Instead, a new 'crypto_probesession' method has been
  added to the kobj interface for symmteric crypto drivers.  This
  method returns a negative value on success (similar to how
  device_probe works) and the crypto framework uses this value to pick
  the "best" driver.  There are three constants for hardware
  (e.g. ccr), accelerated software (e.g. aesni), and plain software
  (cryptosoft) that give preference in that order.  One effect of this
  is that if you request only hardware when creating a new session,
  you will no longer get a session using accelerated software.
  Another effect is that the default setting to disallow software
  crypto via /dev/crypto now disables accelerated software.

  Once a driver is chosen, 'crypto_newsession' is invoked as before.

- Crypto operations are now solely described by the flat 'cryptop'
  structure.  The linked list of descriptors has been removed.

  A separate enum has been added to describe the type of data buffer
  in use instead of using CRYPTO_F_* flags to make it easier to add
  more types in the future if needed (e.g. wired userspace buffers for
  zero-copy).  It will also make it easier to re-introduce separate
  input and output buffers (in-kernel TLS would benefit from this).

  Try to make the flags related to IV handling less insane:

  - CRYPTO_F_IV_SEPARATE means that the IV is stored in the 'crp_iv'
    member of the operation structure.  If this flag is not set, the
    IV is stored in the data buffer at the 'crp_iv_start' offset.

  - CRYPTO_F_IV_GENERATE means that a random IV should be generated
    and stored into the data buffer.  This cannot be used with
    CRYPTO_F_IV_SEPARATE.

  If a consumer wants to deal with explicit vs implicit IVs, etc. it
  can always generate the IV however it needs and store partial IVs in
  the buffer and the full IV/nonce in crp_iv and set
  CRYPTO_F_IV_SEPARATE.

  The layout of the buffer is now described via fields in cryptop.
  crp_aad_start and crp_aad_length define the boundaries of any AAD.
  Previously with GCM and CCM you defined an auth crd with this range,
  but for ETA your auth crd had to span both the AAD and plaintext
  (and they had to be adjacent).

  crp_payload_start and crp_payload_length define the boundaries of
  the plaintext/ciphertext.  Modes that only do a single operation
  (COMPRESS, CIPHER, DIGEST) should only use this region and leave the
  AAD region empty.

  If a digest is present (or should be generated), it's starting
  location is marked by crp_digest_start.

  Instead of using the CRD_F_ENCRYPT flag to determine the direction
  of the operation, cryptop now includes an 'op' field defining the
  operation to perform.  For digests I've added a new VERIFY digest
  mode which assumes a digest is present in the input and fails the
  request with EBADMSG if it doesn't match the internally-computed
  digest.  GCM and CCM already assumed this, and the new AEAD mode
  requires this for decryption.  The new ETA mode now also requires
  this for decryption, so IPsec and GELI no longer do their own
  authentication verification.  Simple DIGEST operations can also do
  this, though there are no in-tree consumers.

  To eventually support some refcounting to close races, the session
  cookie is now passed to crypto_getop() and clients should no longer
  set crp_sesssion directly.

- Assymteric crypto operation structures should be allocated via
  crypto_getkreq() and freed via crypto_freekreq().  This permits the
  crypto layer to track open asym requests and close races with a
  driver trying to unregister while asym requests are in flight.

- crypto_copyback, crypto_copydata, crypto_apply, and
  crypto_contiguous_subsegment now accept the 'crp' object as the
  first parameter instead of individual members.  This makes it easier
  to deal with different buffer types in the future as well as
  separate input and output buffers.  It's also simpler for driver
  writers to use.

- bus_dmamap_load_crp() loads a DMA mapping for a crypto buffer.
  This understands the various types of buffers so that drivers that
  use DMA do not have to be aware of different buffer types.

- Helper routines now exist to build an auth context for HMAC IPAD
  and OPAD.  This reduces some duplicated work among drivers.

- Key buffers are now treated as const throughout the framework and in
  device drivers.  However, session key buffers provided when a session
  is created are expected to remain alive for the duration of the
  session.

- GCM and CCM sessions now only specify a cipher algorithm and a cipher
  key.  The redundant auth information is not needed or used.

- For cryptosoft, split up the code a bit such that the 'process'
  callback now invokes a function pointer in the session.  This
  function pointer is set based on the mode (in effect) though it
  simplifies a few edge cases that would otherwise be in the switch in
  'process'.

  It does split up GCM vs CCM which I think is more readable even if there
  is some duplication.

- I changed /dev/crypto to support GMAC requests using CRYPTO_AES_NIST_GMAC
  as an auth algorithm and updated cryptocheck to work with it.

- Combined cipher and auth sessions via /dev/crypto now always use ETA
  mode.  The COP_F_CIPHER_FIRST flag is now a no-op that is ignored.
  This was actually documented as being true in crypto(4) before, but
  the code had not implemented this before I added the CIPHER_FIRST
  flag.

- I have not yet updated /dev/crypto to be aware of explicit modes for
  sessions.  I will probably do that at some point in the future as well
  as teach it about IV/nonce and tag lengths for AEAD so we can support
  all of the NIST KAT tests for GCM and CCM.

- I've split up the exising crypto.9 manpage into several pages
  of which many are written from scratch.

- I have converted all drivers and consumers in the tree and verified
  that they compile, but I have not tested all of them.  I have tested
  the following drivers:

  - cryptosoft
  - aesni (AES only)
  - blake2
  - ccr

  and the following consumers:

  - cryptodev
  - IPsec
  - ktls_ocf
  - GELI (lightly)

  I have not tested the following:

  - ccp
  - aesni with sha
  - hifn
  - kgssapi_krb5
  - ubsec
  - padlock
  - safe
  - armv8_crypto (aarch64)
  - glxsb (i386)
  - sec (ppc)
  - cesa (armv7)
  - cryptocteon (mips64)
  - nlmsec (mips64)

Discussed with:	cem
Relnotes:	yes
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D23677
2020-03-27 18:25:23 +00:00
Mateusz Piotrowski
f04020edc5 Sort UMA macros and create MLINKS for them
This patch is a follow-up to r344518.

Reported by:	ngie

Reviewed by:	hselasky
Differential Revision:	https://reviews.freebsd.org/D24165
2020-03-23 14:04:42 +00:00
Mark Johnston
fffcb56f7a Add COUNTER_U64_SYSINIT() and COUNTER_U64_DEFINE_EARLY().
The aim is to reduce the boilerplate needed today to define and
initialize global counters.  Also add SI_SUB_COUNTER to the sysinit
ordering.

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23977
2020-03-06 19:09:01 +00:00
Warner Losh
68a229849a _Static_assert is to be preferred to CTASSERT.
Document the existing prefernce that _Static_assert be used in preference to the
old CTASSERT we used to use for compile time assertions.
2020-02-27 15:30:13 +00:00
Ed Maste
59ffd5eb99 style.9: update C99 commentary
Make style.9 read as a current statement of C99 preferences, rather than a
description of ongoing changes to our preferred style.  Alsu use the short
form "ISO C99" on the 2nd and later instances rather than repeating the
unwieldy `ISO/IEC 9899:1999 ("ISO C99")` each time.

Reviewed by:	cem, imp, jhb, kib
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23648
2020-02-25 17:18:59 +00:00
Matt Macy
45035becfe Add zfree to zero allocation before free
Key and cookie management typically wants to
avoid information leaks by explicitly zeroing
before free. This routine simplifies that by
permitting consumers to do so without carrying
the size around.

Reviewed by:	jeff@, jhb@
MFC after:	1 week
Sponsored by:	Rubicon Communications, LLC (Netgate)
Differential Revision:	https://reviews.freebsd.org/D22790
2020-02-16 00:12:53 +00:00
Warner Losh
702547720c Remove sparc64 specific bits of the man pages. 2020-02-12 06:52:22 +00:00
Ryan Libby
ec0d828071 uma: add UMA_ZONE_CONTIG, and a default contig_alloc
For now, copy the mbuf allocator.

Reviewed by:	jeff, markj (previous version)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D23237
2020-02-04 22:40:11 +00:00
Warner Losh
51691e26d0 Remove vpo.4
The Parallel Port SCSI adapter was interesting for 100MB ZIP drives, but is no
longer used or maintained. Remove it from the tree.

The Parallel Port microsequencer (microseq.9) is now mostly unused in the tree,
but remains. PPI still refrences it, but doesn't use its full functionality.

Relnotes: Yes
Reviewed by: rgrimes@, Ihor Antonov
Discussed on: arch@
Differential Revision:  https://reviews.freebsd.org/D23389
2020-02-02 04:53:27 +00:00
Mark Johnston
1c29da0279 Reimplement stack capture of running threads on i386 and amd64.
After r355784 the td_oncpu field is no longer synchronized by the thread
lock, so the stack capture interrupt cannot be delievered precisely.
Fix this using a loop which drops the thread lock and restarts if the
wrong thread was sampled from the stack capture interrupt handler.

Change the implementation to use a regular interrupt instead of an NMI.
Now that we drop the thread lock, there is no advantage to the latter.

Simplify the KPIs.  Remove stack_save_td_running() and add a return
value to stack_save_td().  On platforms that do not support stack
capture of running threads, stack_save_td() returns EOPNOTSUPP.  If the
target thread is running in user mode, stack_save_td() returns EBUSY.

Reviewed by:	kib
Reported by:	mjg, pho
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23355
2020-01-31 15:43:33 +00:00
John Baldwin
03fd4409c7 Correct the return types of fueword*().
MFC after:	1 week
Sponsored by:	DARPA
2020-01-23 23:36:58 +00:00
Gleb Smirnoff
a7f12fce22 Remove struct callout_handle. Should have gone with r355732. 2020-01-22 05:47:59 +00:00
Gleb Smirnoff
1d11092814 Change argument order of epoch_call() to more natural, first function,
then its argument.

A miss from r356826.
2020-01-22 02:28:39 +00:00
Emmanuel Vadot
94292d7e95 fdt_pinctrl: Add new methods for gpios
Most of the gpio controller cannot configure or get the configuration
of the pin muxing as it's usually handled in the pinctrl driver.
But they can know what is the pinmuxing driver either because they are
child of it or via the gpio-range property.
Add some new methods to fdt_pinctrl that a pin controller can implement.
Some methods are :
fdt_pinctrl_is_gpio: Use to know if the pin in the gpio mode
fdt_pinctrl_set_flags: Set the flags of the pin (pullup/pulldown etc ...)
fdt_pinctrl_get_flags: Get the flags of the pin (pullup/pulldown etc ...)

The defaults method returns EOPNOTSUPP.

Reviewed by:	ian, bcr (manpages)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D23093
2020-01-16 21:19:27 +00:00
Ryan Libby
54c5ae804f uma: reorganize flags
- Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC.
 - Move flag VTOSLAB from public to private.
 - Introduce public NOTPAGE flag and make HASH private.
 - Introduce public NOTOUCH flag and make OFFPAGE private.
 - Update man page.

The net effect of this should be to make the contract with clients more
clear.  Clients should choose constraints, UMA will figure out how to
implement them.  This also breaks the confusing double meaning of
OFFPAGE.

Reviewed by:	jeff, markj
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
Conrad Meyer
2c1962aba6 epoch.9: Add missing functions, clean up documentation
Various rototilling.
2019-12-28 01:35:32 +00:00
Mateusz Guzik
1f162fef76 Add read-mostly sleepable locks
To be used when like rmlocks, except when sleeping for readers needs to be
allowed. See the manpage for more information.

Reviewed by:	kib (previous version)
Differential Revision:	https://reviews.freebsd.org/D22823
2019-12-27 11:19:57 +00:00
Conrad Meyer
f3bae413e9 random(9): Deprecate random(9), remove meaningless srandom(9)
srandom(9) is meaningless on SMP systems or any system with, say,
interrupts.  One could never rely on random(9) to produce a reproducible
sequence of outputs on the basis of a specific srandom() seed because the
global state was shared by all kernel contexts.  As such, removing it is
literally indistinguishable to random(9) consumers (as compared with
retaining it).

Mark random(9) as deprecated and slated for quick removal.  This is not to
say we intend to remove all fast, non-cryptographic PRNG(s) in the kernel.
It/they just won't be random(9), as it exists today, in either name or
implementation.

Before random(9) is removed, a replacement will be provided and in-tree
consumers will be converted.

Note that despite the name, the random(9) interface does not bear any
resemblance to random(3).  Instead, it is the same crummy 1988 Park-Miller
LCG used in libc rand(3).
2019-12-26 19:41:09 +00:00
Conrad Meyer
fea73412a0 sleep(9), sleepqueue(9): const'ify wchan pointers
_sleep(9), wakeup(9), sleepqueue(9), et al do not dereference or modify the
channel pointers provided in any way; they are merely used as intptrs into a
dictionary structure to match waiters with wakers.  Correctly annotate this
such that _sleep() and wakeup() may be used on const pointers without
invoking ugly patterns like __DECONST().  Plumb const through all of the
underlying sleepqueue bits.

No functional change.

Reviewed by:	rlibby
Discussed with:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D22914
2019-12-24 16:19:33 +00:00
Scott Long
757d4fbaa7 Introduce the concept of busdma tag templates. A template can be allocated
off the stack, initialized to default values, and then filled in with
driver-specific values, all without having to worry about the numerous
other fields in the tag. The resulting template is then passed into
busdma and the normal opaque tag object created.  See the man page for
details on how to initialize a template.

Templates do not support tag filters.  Filters have been broken for many
years, and only existed for an ancient make/model of hardware that had a
quirky DMA engine.  Instead of breaking the ABI/API and changing the
arugment signature of bus_dma_tag_create() to remove the filter arguments,
templates allow us to ignore them, and also significantly reduce the
complexity of creating and managing tags.

Reviewed by:	imp, kib
Differential Revision:	https://reviews.freebsd.org/D22906
2019-12-24 14:48:46 +00:00
John Baldwin
f236a86702 Bump Dd for changes in r355866.
Pointy hat to:	jhb
MFC after:	2 weeks
2019-12-18 01:27:49 +00:00
John Baldwin
284789e871 Update the crypto(4) and crypto(9) manpages.
There are probably bits that are still wrong, but this fixes some
things at least:
- Add named arguments to the functions in crypto(9).
- Add missing algorithms.
- Don't mention arguments that don't exist in crypto_register.
- Add CIOGSESSION2.
- Remove CIOCNFSESSION.
- Clarify some stale language that assumed an fd had only one sesson.
- Note that you have to use CRIOGET and add a note in BUGS lamenting
  that one has to use CRIOGET.
- Various other cleanups.

Reviewed by:	cem (earlier version)
MFC after:	2 weeks
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D22784
2019-12-17 22:58:07 +00:00
Warner Losh
c0834910ca Better copyright advice
Document the common practices around copyrights with "all rights reserved" in
them as new copyright notices get added.

It's an open question qhether to point people at the fact that since the Berne
convention was ratified, All rights reserved is largely obsolete.
https://en.wikipedia.org/wiki/All_rights_reserved#Obsolescence has the
details. The committer's guide will be revised shortly, and it's likely that's a
better place for this discussion. If not, I'll add a blurb here.

Reviewed by: jhb@, brooks@
Differential Review: https://reviews.freebsd.org/D22800
2019-12-13 22:32:05 +00:00
Warner Losh
16db09d8c1 Don't use contractions. Fix the date.
Contractions cause problems for translators, so s/aren't/are not/ in the one
place this slipped through.

While here, noticed I commited with the date I did the work, not today's
date. Fix that too.

Noticed by: bjk@
2019-12-13 21:39:10 +00:00
John Baldwin
4b28d96e5d Remove the deprecated timeout(9) interface.
All in-tree consumers have been converted to callout(9).

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D22602
2019-12-13 21:03:12 +00:00
Warner Losh
b832a7e505 Create new wrapper function: bus_delayed_attach_children()
Delay the attachment of children, when requested, until after interrutps are
running. This is often needed to allow children to run transactions on i2c or
spi busses. It's a common enough idiom that it will be useful to have its own
wrapper.

Reviewed by: ian
Differential Revision: https://reviews.freebsd.org/D21465
2019-12-13 19:39:33 +00:00
Ryan Libby
9825eadf2c bitset: rename confusing macro NAND to ANDNOT
s/BIT_NAND/BIT_ANDNOT/, and for CPU and DOMAINSET too.  The actual
implementation is "and not" (or "but not"), i.e. A but not B.
Fortunately this does appear to be what all existing callers want.

Don't supply a NAND (not (A and B)) operation at this time.

Discussed with:	jeff
Reviewed by:	cem
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D22791
2019-12-13 09:32:16 +00:00
John Baldwin
a8a03706fb Add a callout_func_t typedef for functions used with callout_*().
This typedef is the same as timeout_t except that it is in the callout
namespace and header.

Use this typedef in various places of the callout implementation that
were either using the raw type or timeout_t.

While here, add <sys/callout.h> to the manpage.

Reviewed by:	kib, imp
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D22751
2019-12-10 21:58:30 +00:00
Mateusz Guzik
abd80ddb94 vfs: introduce v_irflag and make v_type smaller
The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.

v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.

Reviewed by:	kib, jeff
Differential Revision:	https://reviews.freebsd.org/D22715
2019-12-08 21:30:04 +00:00
Warner Losh
a7147da9d4 Fix accidentally changed copyright year.
Noticed by: bapt@
2019-12-04 16:55:55 +00:00
Warner Losh
a339dcccb0 Regularize copyright notices for me.
Remove stray All Rights Reserved and other non-license stuff. Make sure all
copyrights have year.
2019-12-03 15:48:28 +00:00
Mark Johnston
003cf08ba9 Revise the page cache size policy.
In r353734 the use of the page caches was limited to systems with a
relatively large amount of RAM per CPU.  This was to mitigate some
issues reported with the system not able to keep up with memory pressure
in cases where it had been able to do so prior to the addition of the
direct free pool cache.  This change re-enables those caches.

The change modifies uma_zone_set_maxcache(), which was introduced
specifically for the page cache zones.  Rather than using it to limit
only the full bucket cache, have it also set uz_count_max to provide an
upper bound on the per-CPU cache size that is consistent with the number
of items requested.  Remove its return value since it has no use.

Enable the page cache zones unconditionally, and limit them to 0.1% of
the domain's pages.  The limit can be overridden by the
vm.pgcache_zone_max tunable as before.

Change the item size parameter passed to uma_zcache_create() to the
correct size, and stop setting UMA_ZONE_MAXBUCKET.  This allows the page
cache buckets to be adaptively sized, like the rest of UMA's caches.
This also causes the initial bucket size to be small, so only systems
which benefit from large caches will get them.

Reviewed by:	gallatin, jeff
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
Rick Macklem
84208c00bc Update the VOP_COPY_FILE_RANGE man page to reflect the semantic change
made by r354574.

This is a content change.
2019-11-10 01:21:10 +00:00
Rick Macklem
282c7fdc5f Update the VOP_COPY_FILE_RANGE.9 man page to reflect the semantic change
implemented by r354564.

This is a content change.
2019-11-08 23:58:33 +00:00
Rick Macklem
b2ea509012 Fix the man page to correctly describe the use of the "len" argument.
The man page incorrectly described the use of the"len" argument, which
is updated to the number of bytes copied and not reduced by the number
of bytes copied.

This is a content change.
2019-11-08 06:40:17 +00:00
Andriy Gapon
337f6465a9 document taskqueue_start_threads_in_proc
While here, fix taskqueue_start_threads_cpuset that was documented under
old name of taskqueue_start_threads_pinned.

MFC after:	4 weeks
2019-10-17 06:58:07 +00:00
Andriy Gapon
c812bea351 add superio.4 and superio.9 manual pages
This adds basic documentation on what the superio driver is and how
other drivers can interact with it.  I decided to also document
superio's ivar accessors.

Reviewed by:	bcr, brueffer (both manual contents only)
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D21958
2019-10-11 11:13:47 +00:00
Andriy Gapon
93d9a79816 remove unrelated files accidentally committed in r353381 2019-10-10 07:41:42 +00:00
Andriy Gapon
d0c0856f63 emulate illumos membar_producer with atomic_thread_fence_rel
membar_producer is supposed to be a store-store barrier.
Also, in the code that FreeBSD has ported from illumos membar_producer
is used only with regular stores to regular memory (with respect to
caching).

We do not have an MI primitive for the store-store barrier, so
atomic_thread_fence_rel is the closest we have as it provides
(load | store) -> store barrier.

Previously, membar_producer was an empty function call on all 32-bit
arm-s, 32-bit powerpc, riscv and all mips variants.  I think that it was
inadequate.
On other platforms, such as amd64, arm64, i386, powerpc64, sparc64,
membar_producer was implemented using stronger primitives than required
for a store-store barrier with respect to regular memory access.
For example, it used sfence on amd64 and lock-ed nop in i386 (despite TSO).
On powerpc64 we now use recommended lwsync instead of eieio.
On sparc64 FreeBSD uses TSO mode.
On arm64/aarch64 we now use dmb sy instead of dmb ish.  Not sure if this
is an improvement, actually.

After this change we can drop opensolaris_atomic.S for aarch64, amd64,
powerpc64 and sparc64 as all required atomic operations have either
direct or light-weight mapping to FreeBSD native atomic operations.

Discussed with:	kib
MFC after:	4 weeks
2019-10-10 07:39:41 +00:00
Mark Johnston
38a20ba16f Fix a couple of nits in r352110.
- Remove a dead variable from the amd64 pmap_extract_and_hold().
- Fix grammar in the vm_page_wire man page.

Reported by:	alc
Reviewed by:	alc, kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D21639
2019-09-16 15:06:19 +00:00
Mark Johnston
e8bcf6966b Revert r352406, which contained changes I didn't intend to commit. 2019-09-16 15:04:45 +00:00
Mark Johnston
41fd4b9422 Fix a couple of nits in r352110.
- Remove a dead variable from the amd64 pmap_extract_and_hold().
- Fix grammar in the vm_page_wire man page.

Reported by:	alc
Reviewed by:	alc, kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D21639
2019-09-16 15:03:12 +00:00
Yuri Pankov
e3e469850c sbuf(9): fix sbuf_drain_func typedef markup
Reviewed by:	0mp (previous version)
Differential Revision:	https://reviews.freebsd.org/D21569
2019-09-16 13:10:03 +00:00
Mark Johnston
fee2a2fa39 Change synchonization rules for vm_page reference counting.
There are several mechanisms by which a vm_page reference is held,
preventing the page from being freed back to the page allocator.  In
particular, holding the page's object lock is sufficient to prevent the
page from being freed; holding the busy lock or a wiring is sufficent as
well.  These references are protected by the page lock, which must
therefore be acquired for many per-page operations.  This results in
false sharing since the page locks are external to the vm_page
structures themselves and each lock protects multiple structures.

Transition to using an atomically updated per-page reference counter.
The object's reference is counted using a flag bit in the counter.  A
second flag bit is used to atomically block new references via
pmap_extract_and_hold() while removing managed mappings of a page.
Thus, the reference count of a page is guaranteed not to increase if the
page is unbusied, unmapped, and the object's write lock is held.  As
a consequence of this, the page lock no longer protects a page's
identity; operations which move pages between objects are now
synchronized solely by the objects' locks.

The vm_page_wire() and vm_page_unwire() KPIs are changed.  The former
requires that either the object lock or the busy lock is held.  The
latter no longer has a return value and may free the page if it releases
the last reference to that page.  vm_page_unwire_noq() behaves the same
as before; the caller is responsible for checking its return value and
freeing or enqueuing the page as appropriate.  vm_page_wire_mapped() is
introduced for use in pmap_extract_and_hold().  It fails if the page is
concurrently being unmapped, typically triggering a fallback to the
fault handler.  vm_page_wire() no longer requires the page lock and
vm_page_unwire() now internally acquires the page lock when releasing
the last wiring of a page (since the page lock still protects a page's
queue state).  In particular, synchronization details are no longer
leaked into the caller.

The change excises the page lock from several frequently executed code
paths.  In particular, vm_object_terminate() no longer bounces between
page locks as it releases an object's pages, and direct I/O and
sendfile(SF_NOCACHE) completions no longer require the page lock.  In
these latter cases we now get linear scalability in the common scenario
where different threads are operating on different files.

__FreeBSD_version is bumped.  The DRM ports have been updated to
accomodate the KPI changes.

Reviewed by:	jeff (earlier version)
Tested by:	gallatin (earlier version), pho
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D20486
2019-09-09 21:32:42 +00:00
Mark Johnston
e46cfc2542 Revert a portion of r351628 that I did not mean to commit.
Reported by:	mjg
MFC with:	r351628
2019-09-03 14:39:36 +00:00
Mark Johnston
08cfa56ea3 Extend uma_reclaim() to permit different reclamation targets.
The page daemon periodically invokes uma_reclaim() to reclaim cached
items from each zone when the system is under memory pressure.  This
is important since the size of these caches is unbounded by default.
However it also results in bursts of high latency when allocating from
heavily used zones as threads miss in the per-CPU caches and must
access the keg in order to allocate new items.

With r340405 we maintain an estimate of each zone's usage of its
(per-NUMA domain) cache of full buckets.  Start making use of this
estimate to avoid reclaiming the entire cache when under memory
pressure.  In particular, introduce TRIM, DRAIN and DRAIN_CPU
verbs for uma_reclaim() and uma_zone_reclaim().  When trimming, only
items in excess of the estimate are reclaimed.  Draining a zone
reclaims all of the cached full buckets (the previous behaviour of
uma_reclaim()), and may further drain the per-CPU caches in extreme
cases.

Now, when under memory pressure, the page daemon will trim zones
rather than draining them.  As a result, heavily used zones do not incur
bursts of bucket cache misses following reclamation, but large, unused
caches will be reclaimed as before.

Reviewed by:	jeff
Tested by:	pho (an earlier version)
MFC after:	2 months
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
Mark Johnston
d794b3a3c2 Update and clean up the UMA man page.
- Fix warnings from igor and mandoc.
- Provide a brief description of the separation between zones and their
  backend slab allocators.
- Document cache zones and secondary zones.
- Document the kernel config options added in r350659.
- Document the uma_zalloc_pcpu() and uma_zfree_pcpu() wrappers.
- Document uma_zone_reserve(), uma_zone_reserve_kva() and
  uma_zone_prealloc().
- Document uma_zone_alloc() and uma_zone_freef().
- Add some missing MLINKs and Xrefs.

MFC after:	2 weeks
2019-08-30 19:35:44 +00:00
John Baldwin
93a0379392 Trim a spurious blank line I added in r348969.
I did not bump .Dd since there is no content change.

MFC after:	3 days
2019-08-19 17:28:12 +00:00
Konstantin Belousov
3a91d1062a i386: Implement atomic_load_64(9) and atomic_store_64(9).
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2019-08-18 15:58:44 +00:00