Supply a new memory manager for RuntimeDyld, to avoid crashes in
generated code caused by memory placement that can overflow a 32 bit
data type. This is a drop-in replacement for the
llvm::SectionMemoryManager class in the LLVM library, with Michael
Smith's proposed fix from
https://www.github.com/llvm/llvm-project/pull/71968.
We hereby slurp it into our own source tree, after moving into a new
namespace llvm::backport and making some minor adjustments so that it
can be compiled with older LLVM versions as far back as 12. It's harder
to make it work on even older LLVM versions, but it doesn't seem likely
that people are really using them so that is not investigated for now.
The problem could also be addressed by switching to JITLink instead of
RuntimeDyld, and that is the LLVM project's recommended solution as
the latter is about to be deprecated. We'll have to do that soon enough
anyway, and then when the LLVM version support window advances far
enough in a few years we'll be able to delete this code. Unfortunately
that wouldn't be enough for PostgreSQL today: in most relevant versions
of LLVM, JITLink is missing or incomplete.
Several other projects have already back-ported this fix into their fork
of LLVM, which is a vote of confidence despite the lack of commit into
LLVM as of today. We don't have our own copy of LLVM so we can't do
exactly what they've done; instead we have a copy of the whole patched
class so we can pass an instance of it to RuntimeDyld.
The LLVM project hasn't chosen to commit the fix yet, and even if it
did, it wouldn't be back-ported into the releases of LLVM that most of
our users care about, so there is not much point in waiting any longer
for that. If they make further changes and commit it to LLVM 19 or 20,
we'll still need this for older versions, but we may want to
resynchronize our copy and update some comments.
The changes that we've had to make to our copy can be seen by diffing
our SectionMemoryManager.{h,cpp} files against the ones in the tree of
the pull request. Per the LLVM project's license requirements, a copy
is in SectionMemoryManager.LICENSE.
This should fix the spate of crash reports we've been receiving lately
from users on large memory ARM systems.
Back-patch to all supported releases.
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Co-authored-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se> (license aspects)
Reported-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Discussion: https://postgr.es/m/CAO6_Xqr63qj%3DSx7HY6ZiiQ6R_JbX%2B-p6sTPwDYwTWZjUmjsYBg%40mail.gmail.com
We had been using "diff -upd", which evidently works for most people,
but Solaris's diff doesn't like it. (We'd not noticed because the
Solaris buildfarm animals weren't running this test until they were
upgraded to the latest buildfarm client script.) Change to "diff -U3"
which is what pg_regress has used for ages.
Per buildfarm (and off-list discussion with Noah Misch).
Back-patch to v16 where this test was added. In v16,
also back-patch the relevant part of 628c1d1f2 so that
the test script looks about the same in all branches.
This reverts commit 95c5acb3fc (v17) and
counterparts in each other non-master branch. If released, that commit
would have caused a worst-in-years minor release regression, via
undetected LWLock self-deadlock. This commit and its self-deadlock fix
warrant more bake time in the master branch.
Reported by Alexander Lakhin.
Discussion: https://postgr.es/m/10ec0bc3-5933-1189-6bb8-5dec4114558e@gmail.com
The inplace update survives ROLLBACK. The inval didn't, so another
backend's DDL could then update the row without incorporating the
inplace update. In the test this fixes, a mix of CREATE INDEX and ALTER
TABLE resulted in a table with an index, yet relhasindex=f. That is a
source of index corruption. Back-patch to v12 (all supported versions).
The back branch versions don't change WAL, because those branches just
added end-of-recovery SIResetAll(). All branches change the ABI of
extern function PrepareToInvalidateCacheTuple(). No PGXN extension
calls that, and there's no apparent use case in extensions.
Reviewed by Nitin Motiani and (in earlier versions) Andres Freund.
Discussion: https://postgr.es/m/20240523000548.58.nmisch@google.com
... to fix bugs when the referenced table is partitioned.
The catalog representation we chose for foreign keys connecting
partitioned tables (in commit f56f8f8da6) is inconvenient, in the
sense that a standalone table has a different way to represent the
constraint when referencing a partitioned table, than when the same
table becomes a partition (and vice versa). Because of this, we need to
create additional catalog rows on detach (pg_constraint and pg_trigger),
and remove them on attach. We were doing some of those things, but not
all of them, leading to missing catalog rows in certain cases.
The worst problem seems to be that we are missing action triggers after
detaching a partition, which means that you could update/delete rows
from the referenced partitioned table that still had referencing rows on
that table, the server failing to throw the required errors.
!!!
Note that this means existing databases with FKs that reference
partitioned tables might have rows that break relational integrity, on
tables that were once partitions on the referencing side of the FK.
Another possible problem is that trying to reattach a table
that had been detached would fail indicating that internal triggers
cannot be found, which from the user's point of view is nonsensical.
In branches 15 and above, we fix this by creating a new helper function
addFkConstraint() which is in charge of creating a standalone
pg_constraint row, and repurposing addFkRecurseReferencing() and
addFkRecurseReferenced() so that they're only the recursive routine for
each side of the FK, and they call addFkConstraint() to create
pg_constraint at each partitioning level and add the necessary triggers.
These new routines can be used during partition creation, partition
attach and detach, and foreign key creation. This reduces redundant
code and simplifies the flow.
In branches 14 and 13, we have a much simpler fix that consists on
simply removing the constraint on detach. The reason is that those
branches are missing commit f4566345cf, which reworked the way this
works in a way that we didn't consider back-patchable at the time.
We opted to leave branch 12 alone, because it's different from branch 13
enough that the fix doesn't apply; and because it is going in EOL mode
very soon, patching it now might be worse since there's no way to undo
the damage if it goes wrong.
Existing databases might need to be repaired.
In the future we might want to rethink the catalog representation to
avoid this problem, but for now the code seems to do what's required to
make the constraints operate correctly.
Co-authored-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Co-authored-by: Tender Wang <tndrwang@gmail.com>
Co-authored-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Guillaume Lelarge <guillaume@lelarge.info>
Reported-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Reported-by: Thomas Baehler (SBB CFF FFS) <thomas.baehler2@sbb.ch>
Discussion: https://postgr.es/m/20230420144344.40744130@karst
Discussion: https://postgr.es/m/20230705233028.2f554f73@karst
Discussion: https://postgr.es/m/GVAP278MB02787E7134FD691861635A8BC9032@GVAP278MB0278.CHEP278.PROD.OUTLOOK.COM
Discussion: https://postgr.es/m/18541-628a61bc267cd2d3@postgresql.org
Commit 149ac7d455 which re-implemented pgindent in Perl explicitly
imported the devnull function from File::Spec, but the module does
not export anything. In recent versions of Perl calling a missing
import function cause a warning, which combined with warnings being
fatal cause pgindent to error out.
Backpatch to all supported versions.
Author: Erik Wienhold <ewie@ewie.name>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discusson: https://postgr.es/m/2372cd74-11b0-46f9-b28e-8f9627215d19@ewie.name
Backpatch-through: v12
Latest versions of Strawberry Perl define USE_THREAD_SAFE_LOCALE, and we
therefore get a handshake error when building against such instances.
The solution is to perform a test to see if USE_THREAD_SAFE_LOCALE is
defined and only define NO_THREAD_SAFE_LOCALE if it isn't.
Backpatch the meson.build fix back to release 16 and apply the same
logic to Mkvcbuild.pm in releases 12 through 16.
Original report of the issue from Muralikrishna Bandaru.
MacPorts version 2.9.3 started failing in our ci_macports_packages.sh
script, for reasons not fully determined, but plausibly linked to the
release of 2.10.1. 2.10.1 seems to work, so let's switch to it.
Back-patch to 15, where CI began.
Reported-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/81f104e8-f0a9-43c0-85bd-2bbbf590a5b8%40eisentraut.org
Commit d01ce180 invented a new way to find the latest MacPorts version.
By bad luck, a new beta release has just been published, and it seems
to lack some packages we need. Go back to searching for this specific
version for now. We still search with a pattern so that we can find the
package for the running version of macOS, but for now we always look for
2.9.3. The code to do that had been anticipated already in a commented
out line, I just didn't expect to have to use it so soon...
Also include the whole MacPorts installation script in the cache key, so
that changes to the script cause a fresh installation. This should make
it a bit easier to reason about the effect of changes on cached state in
github accounts using CI, when we make adjustments.
Back-patch to 15, like d01ce180.
Discussion: https://postgr.es/m/CA%2BhUKGLqJdv6RcwyZ_0H7khxtLTNJyuK%2BvDFzv3uwYbn8hKH6A%40mail.gmail.com
1. Previously we were using ghcr.io/cirruslabs/macos-XXX-base:latest
images, but Cirrus has started ignoring that and using a particular
image, currently ghcr.io/cirruslabs/macos-runner:sonoma, for github
accounts using free CI resources (as opposed to dedicated runner
machines, as cfbot uses). Let's just ask for that image anyway, to stay
in sync.
2. Instead of hard-coding a MacPorts installation URL, deduce it from
the running macOS version and the available releases. This removes the
need to keep the ci_macports_packages.sh in sync with .cirrus.task.yml,
and to advance the MacPorts version from time to time.
3. Change the cache key we use to cache the whole macports installation
across builds to include the OS major version, to trigger a fresh
installation when appropriate.
Back-patch to 15 where CI began.
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKGLqJdv6RcwyZ_0H7khxtLTNJyuK%2BvDFzv3uwYbn8hKH6A%40mail.gmail.com
macOS 15's SDK pulls in headers related to <regex.h> when we include
<xlocale.h>. This causes our own regex_t implementation to clash with
the OS's regex_t implementation. Luckily our function names already had
pg_ prefixes, but the macros and typenames did not.
Include <regex.h> explicitly on all POSIX systems, and fix everything
that breaks. Then we can prove that we are capable of fully hiding and
replacing the system regex API with our own.
1. Deal with standard-clobbering macros by undefining them all first.
POSIX says they are "symbolic constants". If they are macros, this
allows us to redefine them. If they are enums or variables, our macros
will hide them.
2. Deal with standard-clobbering types by giving our types pg_
prefixes, and then using macros to redirect xxx_t -> pg_xxx_t.
After including our "regex/regex.h", the system <regex.h> is hidden,
because we've replaced all the standard names. The PostgreSQL source
tree and extensions can continue to use standard prefix-less type and
macro names, but reach our implementation, if they included our
"regex/regex.h" header.
Back-patch to all supported branches, so that macOS 15's tool chain can
build them.
Reported-by: Stan Hu <stanhu@gmail.com>
Suggested-by: Tom Lane <tgl@sss.pgh.pa.us>
Tested-by: Aleksander Alekseev <aleksander@timescale.com>
Discussion: https://postgr.es/m/CAMBWrQnEwEJtgOv7EUNsXmFw2Ub4p5P%2B5QTBEgYwiyjy7rAsEQ%40mail.gmail.com
This could have caused spurious failures only on SPARC Linux, because
today's only todo_start tests for that platform. Back-patch to v16,
where Meson support first appeared.
Reviewed by Robert Haas.
Discussion: https://postgr.es/m/20240512232923.aa.nmisch@google.com
We did not recover the subtransaction IDs of prepared transactions
when starting a hot standby from a shutdown checkpoint. As a result,
such subtransactions were considered as aborted, rather than
in-progress. That would lead to hint bits being set incorrectly, and
the subtransactions suddenly becoming visible to old snapshots when
the prepared transaction was committed.
To fix, update pg_subtrans with prepared transactions's subxids when
starting hot standby from a shutdown checkpoint. The snapshots taken
from that state need to be marked as "suboverflowed", so that we also
check the pg_subtrans.
Backport to all supported versions.
Discussion: https://www.postgresql.org/message-id/6b852e98-2d49-4ca1-9e95-db419a2696e0@iki.fi
We missed performing table sync if the invalidation happened while the
non-ready tables list was being prepared. This occurs because the sync
state was set to valid at the end of non-ready table list preparation
irrespective of the invalidations processed while the list is being
prepared.
Fix it by changing the boolean variable to a tri-state enum and by setting
table state to valid only if no invalidations have occurred while the list
is being prepared.
Reprted-by: Alexander Lakhin
Diagnosed-by: Alexander Lakhin
Author: Vignesh C
Reviewed-by: Hou Zhijie, Alexander Lakhin, Ajin Cherian, Amit Kapila
Backpatch-through: 15
Discussion: https://postgr.es/m/711a6afe-edb7-1211-cc27-1bef8239eec7@gmail.com
While back-patching commit 6f0cef935, I forgot that the MSVC
build scripts would also need adjustment in the back branches.
This is a blind attempt at a fix, but it's basically copying
nearby code so I think it will work.
Per buildfarm (via Andrew Dunstan)
Discussion: https://postgr.es/m/4cc4dc47-ca2b-4129-8784-db69b5f82777@dunslane.net
Commit 5579388d removed code that supplied a fallback implementation of
getaddrinfo(), which was dead code on modern systems. One tiny piece of
the removed code was still doing something useful on Windows, though:
that OS's own gai_strerror()/gai_strerrorA() function returns a pointer
to a static buffer that it overwrites each time, so it's not
thread-safe. In rare circumstances, a multi-threaded client program
could get an incorrect or corrupted error message.
Restore the replacement gai_strerror() function, though now that it's
only for Windows we can put it into a win32-specific file and cut it
down to the errors that Windows documents. The error messages here are
taken from FreeBSD, because Windows' own messages seemed too verbose.
Back-patch to 16.
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKGKz%2BF9d2PTiXwfYV7qJw%2BWg2jzACgSDgPizUw7UG%3Di58A%40mail.gmail.com
This commit addresses a set of issues when changing token type mappings
in a text search configuration when using duplicated token names:
- ADD MAPPING would fail on insertion because of a constraint failure
after inserting the same mapping.
- ALTER MAPPING with an "overridden" configuration failed with "tuple
already updated by self" when the token mappings are removed.
- DROP MAPPING failed with "tuple already updated by self", like
previously, but in a different code path.
The code is refactored so the token names (with their numbers) are
handled as a List with unique members rather than an array with numbers,
ensuring that no duplicates mess up with the catalog inserts, updates
and deletes. The list is generated by getTokenTypes(), with the same
error handling as previously while duplicated tokens are discarded from
the list used to work on the catalogs.
Regression tests are expanded to cover much more ground for the cases
fixed by this commit, as there was no coverage for the code touched in
this commit. A bit more is done regarding the fact that a token name
not supported by a configuration's parser should result in an error even
if IF EXISTS is used in a DROP MAPPING clause. This is implied in the
code but there was no coverage for that, and it was very easy to miss.
These issues exist since at least their introduction in core with
140d4ebcb4, so backpatch all the way down.
Reported-by: Alexander Lakhin
Author: Tender Wang, Michael Paquier
Discussion: https://postgr.es/m/18310-1eb233c5908189c8@postgresql.org
Backpatch-through: 12
We should have done it this way all along, but we accidentally got
away with using the wrong BIO field up until OpenSSL 3.2. There,
the library's BIO routines that we rely on use the "data" field
for their own purposes, and our conflicting use causes assorted
weird behaviors up to and including core dumps when SSL connections
are attempted. Switch to using the approved field for the purpose,
i.e. app_data.
While at it, remove our configure probes for BIO_get_data as well
as the fallback implementation. BIO_{get,set}_app_data have been
there since long before any OpenSSL version that we still support,
even in the back branches.
Also, update src/test/ssl/t/001_ssltests.pl to allow for a minor
change in an error message spelling that evidently came in with 3.2.
Tristan Partin and Bo Andreson. Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAN55FZ1eDDYsYaL7mv+oSLUij2h_u6hvD4Qmv-7PK7jkji0uyQ@mail.gmail.com
If an out-of-memory error was thrown at an unfortunate time,
ensure_record_cache_typmod_slot_exists() could leak memory and leave
behind a global state that produced an infinite loop on the next call.
Fix by merging RecordCacheArray and RecordIdentifierArray into a single
array. With only one allocation or re-allocation, there is no
intermediate state.
Back-patch to all supported releases.
Reported-by: "James Pang (chaolpan)" <chaolpan@cisco.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/PH0PR11MB519113E738814BDDA702EDADD6EFA%40PH0PR11MB5191.namprd11.prod.outlook.com
See prior commit for an explanation for the goal of the change and why it had
to be split into two commits.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/20230808021541.7lbzdefvma7qmn3w@awork3.anarazel.de
Backpatch: 15-, where CI support was added
Commit 31966b15 invented a way for functions dealing with relation
extension to accept a Relation in online code and an SMgrRelation in
recovery code. It seems highly likely that future bufmgr.c interfaces
will face the same problem, and need to do something similar.
Generalize the names so that each interface doesn't have to re-invent
the wheel.
Back-patch to 16. Since extension AM authors might start using the
constructor macros once 16 ships, we agreed to do the rename in 16
rather than waiting for 17.
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKG%2B6tLD2BhpRWycEoti6LVLyQq457UL4ticP5xd8LqHySA%40mail.gmail.com
Attribute missing values might be needed past the lifetime of the tuple
descriptors from which they are extracted. To avoid possibly using
pointers for by-reference values which might thus be left dangling, we
cache a datumCopy'd version of the datum in the TopMemoryContext. Since
we first search for the value this only needs to be done once per
session for any such value.
Original complaint from Tom Lane, idea for mitigation by Andrew Dunstan,
tweaked by Tom Lane.
Backpatch to version 11 where missing values were introduced.
Discussion: https://postgr.es/m/1306569.1687978174@sss.pgh.pa.us
A significant chunk of the time on the macos CI task is spent installing
packages using homebrew. The downloads of the packages are cached, but the
installation needs to happen every time. We can't cache the whole homebrew
installation, because it is too large due to pre-installed packages.
Speed this up by installing packages using macports and caching the
installation as .dmg. That's a lot faster than unpacking a tarball.
In addition, don't install llvm - it wasn't enabled when building, so it's
just a waste of time/space.
This substantially speeds up the mac CI time, both in the cold cache and in
the warm cache case (the latter from ~1m20s to ~5s).
It doesn't seem great to have diverging sources of packages for CI between
branches, so backpatch to 15 (where CI was added).
Discussion: https://postgr.es/m/20230805202539.r3umyamsnctysdc7@awork3.anarazel.de
Backpatch: 15-, where CI was added
pgperltidy as well as pgperlcritic and pgperlsyncheck now allow
passing files and directories on the command line, like pgindent does.
(Previously, they would always operate on the whole tree.)
Also, for consistency with pgindent's new behavior (as of b16259b3c1),
passing an argument is now required. To get the previous default
behavior, use "pgperltidy ." for example.
Discussion: https://www.postgresql.org/message-id/flat/45aacd8a-5265-d9da-8df2-b8e2c0cf6a07%40eisentraut.org
Commit f62975b2a made headerscheck and cpluspluscheck a little
smarter than this documentation gave them credit for. Make
their docs match current reality. Also add a warning about the
layer of dust that has settled on the rest of these scripts.
Discussion: https://postgr.es/m/769950.1684797558@sss.pgh.pa.us
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
This is equivalent to a revert of f193883 and fb32748, with the addition
that the declaration of the SQLValueFunction node needs to gain a couple
of node_attr for query jumbling. The performance impact of removing the
function call inlining is proving to be too huge for some workloads
where these are used. A worst-case test case of involving only simple
SELECT queries with a SQL keyword is proving to lead to a reduction of
10% in TPS via pgbench and prepared queries on a high-end machine.
None of the tests I ran back for this set of changes saw such a huge
gap, but Alexander Lakhin and Andres Freund have found that this can be
noticeable. Keeping the older performance would mean to do more
inlining in the executor when using COERCE_SQL_SYNTAX for a function
expression, similarly to what SQLValueFunction does. This requires more
redesign work and there is little time until 16beta1 is released, so for
now reverting the change is the best way forward, bringing back the
previous performance.
Bump catalog version.
Reported-by: Alexander Lakhin
Discussion: https://postgr.es/m/b32bed1b-0746-9b20-1472-4bdc9ca66d52@gmail.com
Calling fseek() or ftello() on a handle to a non-seeking device such as
a pipe or a communications device is not supported. Unfortunately,
MSVC's flavor of these routines, _fseeki64() and _ftelli64(), do not
return an error when given a pipe as handle. Some of the logic of
pg_dump and restore relies on these routines to check if a handle is
seekable, causing failures when passing the contents of pg_dump to
pg_restore through a pipe, for example.
This commit introduces wrappers for fseeko() and ftello() on MSVC so as
any callers are able to properly detect the cases of non-seekable
handles. This relies mainly on GetFileType(), sharing a bit of code
with the MSVC port for fstat(). The code in charge of getting a file
type is refactored into a new file called win32common.c, shared by
win32stat.c and the new win32fseek.c. It includes the MSVC ports for
fseeko() and ftello().
Like 765f5df, this is backpatched down to 14, where the fstat()
implementation for MSVC is able to understand about files larger than
4GB in size. Using a TAP test for that is proving to be tricky as
IPC::Run handles the pipes by itself, still I have been able to check
the fix manually.
Reported-by: Daniel Watzinger
Author: Juan José Santamaría Flecha, Michael Paquier
Discussion: https://postgr.es/m/CAC+AXB26a4EmxM2suXxPpJaGrqAdxracd7hskLg-zxtPB50h7A@mail.gmail.com
Backpatch-through: 14
If a variable has an initialization expression that wraps onto the
next line(s), pg_bsd_indent will now indent the continuation lines
one stop, instead of aligning them flush with the variable declaration.
We've been holding off applying this until the last v16 CF finished,
but now it's time.
Thomas Munro and Tom Lane
Discussion: https://postgr.es/m/20230120013137.7ky7nl4e4zjorrfa@awork3.anarazel.de
This is mainly useful because the upcoming logical-decoding-on-standby feature
adds further reasons for invalidating slots, and we don't want to end up with
multiple invalidated_* fields, or check different attributes.
Eventually we should consider not resetting restart_lsn when invalidating a
slot due to max_slot_wal_keep_size. But that's a user visible change, so left
for later.
Increases SLOT_VERSION, due to the changed field (with a different alignment,
no less).
Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
In order to have the option to use O_DIRECT/FILE_FLAG_NO_BUFFERING in a
later commit, we need the addresses of user space buffers to be well
aligned. The exact requirements vary by OS and file system (typically
sectors and/or memory pages). The address alignment size is set to
4096, which is enough for currently known systems: it matches modern
sectors and common memory page size. There is no standard governing
O_DIRECT's requirements so we might eventually have to reconsider this
with more information from the field or future systems.
Aligning I/O buffers on memory pages is also known to improve regular
buffered I/O performance.
Three classes of I/O buffers for regular data pages are adjusted:
(1) Heap buffers are now allocated with the new palloc_aligned() or
MemoryContextAllocAligned() functions introduced by commit 439f6175.
(2) Stack buffers now use a new struct PGIOAlignedBlock to respect
PG_IO_ALIGN_SIZE, if possible with this compiler. (3) The buffer
pool is also aligned in shared memory.
WAL buffers were already aligned on XLOG_BLCKSZ. It's possible for
XLOG_BLCKSZ to be configured smaller than PG_IO_ALIGNED_SIZE and thus
for O_DIRECT WAL writes to fail to be well aligned, but that's a
pre-existing condition and will be addressed by a later commit.
BufFiles are not yet addressed (there's no current plan to use O_DIRECT
for those, but they could potentially get some incidental speedup even
in plain buffered I/O operations through better alignment).
If we can't align stack objects suitably using the compiler extensions
we know about, we disable the use of O_DIRECT by setting PG_O_DIRECT to
0. This avoids the need to consider systems that have O_DIRECT but
can't align stack objects the way we want; such systems could in theory
be supported with more work but we don't currently know of any such
machines, so it's easier to pretend there is no O_DIRECT support
instead. That's an existing and tested class of system.
Add assertions that all buffers passed into smgrread(), smgrwrite() and
smgrextend() are correctly aligned, unless PG_O_DIRECT is 0 (= stack
alignment tricks may be unavailable) or the block size has been set too
small to allow arrays of buffers to be all aligned.
Author: Thomas Munro <thomas.munro@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/CA+hUKGK1X532hYqJ_MzFWt0n1zt8trz980D79WbjwnT-yYLZpg@mail.gmail.com
a9c70b46db and 8aaa04b32S added counting of IO operations to a new view,
pg_stat_io. Now, add IO timing for reads, writes, extends, and fsyncs to
pg_stat_io as well.
This combines the tracking for pgBufferUsage with the tracking for pg_stat_io
into a new function pgstat_count_io_op_time(). This should make it a bit
easier to avoid the somewhat costly instr_time conversion done for
pgBufferUsage.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_ay5iKmnbXZ3DsauViF3eMxu4m1oNnJXqV_HyqYeg55Ww%40mail.gmail.com
The primary bottlenecks for relation extension are:
1) The extension lock is held while acquiring a victim buffer for the new
page. Acquiring a victim buffer can require writing out the old page
contents including possibly needing to flush WAL.
2) When extending via ReadBuffer() et al, we write a zero page during the
extension, and then later write out the actual page contents. This can
nearly double the write rate.
3) The existing bulk relation extension infrastructure in hio.c just amortized
the cost of acquiring the relation extension lock, but none of the other
costs.
Unfortunately 1) cannot currently be addressed in a central manner as the
callers to ReadBuffer() need to acquire the extension lock. To address that,
this this commit moves the responsibility for acquiring the extension lock
into bufmgr.c functions. That allows to acquire the relation extension lock
for just the required time. This will also allow us to improve relation
extension further, without changing callers.
The reason we write all-zeroes pages during relation extension is that we hope
to get ENOSPC errors earlier that way (largely works, except for CoW
filesystems). It is easier to handle out-of-space errors gracefully if the
page doesn't yet contain actual tuples. This commit addresses 2), by using the
recently introduced smgrzeroextend(), which extends the relation, without
dirtying the kernel page cache for all the extended pages.
To address 3), this commit introduces a function to extend a relation by
multiple blocks at a time.
There are three new exposed functions: ExtendBufferedRel() for extending the
relation by a single block, ExtendBufferedRelBy() to extend a relation by
multiple blocks at once, and ExtendBufferedRelTo() for extending a relation up
to a certain size.
To avoid duplicating code between ReadBuffer(P_NEW) and the new functions,
ReadBuffer(P_NEW) now implements relation extension with
ExtendBufferedRel(), using a flag to tell ExtendBufferedRel() that the
relation lock is already held.
Note that this commit does not yet lead to a meaningful performance or
scalability improvement - for that uses of ReadBuffer(P_NEW) will need to be
converted to ExtendBuffered*(), which will be done in subsequent commits.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/20221029025420.eplyow6k7tgu6he3@awork3.anarazel.de
Allow pg_dump to use the zstd compression, in addition to gzip/lz4. Bulk
of the new compression method is implemented in compress_zstd.{c,h},
covering the pg_dump compression APIs. The rest of the patch adds test
and makes various places aware of the new compression method.
The zstd library (which this patch relies on) supports multithreaded
compression since version 1.5. We however disallow that feature for now,
as it might interfere with parallel backups on platforms that rely on
threads (e.g. Windows). This can be improved / relaxed in the future.
This also fixes a minor issue in InitDiscoverCompressFileHandle(), which
was not updated to check if the file already has the .lz4 extension.
Adding zstd compression was originally proposed in 2020 (see the second
thread), but then was reworked to use the new compression API introduced
in e9960732a9. I've considered both threads when compiling the list of
reviewers.
Author: Justin Pryzby
Reviewed-by: Tomas Vondra, Jacob Champion, Andreas Karlsson
Discussion: https://postgr.es/m/20230224191840.GD1653@telsasoft.com
Discussion: https://postgr.es/m/20201221194924.GI30237@telsasoft.com
