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| author | Thomas Munro <tmunro@postgresql.org> | 2021-07-19 08:52:00 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2021-07-19 11:01:01 +1200 |
| commit | 2dbe8905711ba09a2214b6e835f8f0c2c4981cb3 (patch) | |
| tree | 775e44cb05c4dfa8f12e68eb388f04e9aa252c96 /src/bin/pg_test_fsync | |
| parent | f157db862225a7bfe041ca3f7b73e913e2a8d8d6 (diff) | |
| download | postgresql-2dbe8905711ba09a2214b6e835f8f0c2c4981cb3.tar.gz postgresql-2dbe8905711ba09a2214b6e835f8f0c2c4981cb3.zip | |
Support direct I/O on macOS.
Macs don't understand O_DIRECT, but they can disable caching with a
separate fcntl() call. Extend the file opening functions in fd.c to
handle this for us if the caller passes in PG_O_DIRECT.
For now, this affects only WAL data and even then only if you set:
max_wal_senders=0
wal_level=minimal
This is not expected to be very useful on its own, but later proposed
patches will make greater use of direct I/O, and it'll be useful for
testing if developers on Macs can see the effects.
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKG%2BADiyyHe0cun2wfT%2BSVnFVqNYPxoO6J9zcZkVO7%2BNGig%40mail.gmail.com
Diffstat (limited to 'src/bin/pg_test_fsync')
| -rw-r--r-- | src/bin/pg_test_fsync/pg_test_fsync.c | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/src/bin/pg_test_fsync/pg_test_fsync.c b/src/bin/pg_test_fsync/pg_test_fsync.c index 78dab5096c6..fef31844fa0 100644 --- a/src/bin/pg_test_fsync/pg_test_fsync.c +++ b/src/bin/pg_test_fsync/pg_test_fsync.c @@ -217,8 +217,10 @@ handle_args(int argc, char *argv[]) "%u seconds per test\n", secs_per_test), secs_per_test); -#if PG_O_DIRECT != 0 +#if defined(O_DIRECT) printf(_("O_DIRECT supported on this platform for open_datasync and open_sync.\n")); +#elif defined(F_NOCACHE) + printf(_("F_NOCACHE supported on this platform for open_datasync and open_sync.\n")); #else printf(_("Direct I/O is not supported on this platform.\n")); #endif @@ -258,6 +260,31 @@ test_open(void) close(tmpfile); } +static int +open_direct(const char *path, int flags, mode_t mode) +{ + int fd; + +#ifdef O_DIRECT + flags |= O_DIRECT; +#endif + + fd = open(path, flags, mode); + +#if !defined(O_DIRECT) && defined(F_NOCACHE) + if (fd >= 0 && fcntl(fd, F_NOCACHE, 1) < 0) + { + int save_errno = errno; + + close(fd); + errno = save_errno; + return -1; + } +#endif + + return fd; +} + static void test_sync(int writes_per_op) { @@ -279,7 +306,7 @@ test_sync(int writes_per_op) fflush(stdout); #ifdef OPEN_DATASYNC_FLAG - if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT | PG_BINARY, 0)) == -1) + if ((tmpfile = open_direct(filename, O_RDWR | O_DSYNC | PG_BINARY, 0)) == -1) { printf(NA_FORMAT, _("n/a*")); fs_warning = true; @@ -386,7 +413,7 @@ test_sync(int writes_per_op) fflush(stdout); #ifdef OPEN_SYNC_FLAG - if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT | PG_BINARY, 0)) == -1) + if ((tmpfile = open_direct(filename, O_RDWR | OPEN_SYNC_FLAG | PG_BINARY, 0)) == -1) { printf(NA_FORMAT, _("n/a*")); fs_warning = true; @@ -454,7 +481,7 @@ test_open_sync(const char *msg, int writes_size) fflush(stdout); #ifdef OPEN_SYNC_FLAG - if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT | PG_BINARY, 0)) == -1) + if ((tmpfile = open_direct(filename, O_RDWR | OPEN_SYNC_FLAG | PG_BINARY, 0)) == -1) printf(NA_FORMAT, _("n/a*")); else { |