From 3f53a96a8bd0cd4a18f819b6857e6a764706ede5 Mon Sep 17 00:00:00 2001 From: Filipe David Manana Date: Thu, 22 Apr 2010 23:40:26 +0100 Subject: Add file:datasync/1 for syncing file contents only file:datasync/1 invokes the POSIX system call "int fdatasync(int fd)". This system call is similar to "fsync" but, unlike fsync, it does not update the metadata associated with the file (like the access time for example). It's used by many DBMSs (MySQL and SQLite of example) to increase disk IO performance, as it avoids disk seeks and disk write operations compared to fsync. More details on it at: http://linux.die.net/man/2/fdatasync An example, from the MySQL source: http://bazaar.launchpad.net/~mysql/mysql-server/mysql-5.1-telco-6.1/annotate/head%3A/mysys/my_sync.c#L61 This new function just calls fsync on systems not implementing fdatasync. --- erts/emulator/drivers/common/efile_drv.c | 23 +++++++++++++++++++++++ erts/emulator/drivers/common/erl_efile.h | 1 + erts/emulator/drivers/common/ram_file_drv.c | 8 ++++++++ erts/emulator/drivers/unix/unix_efile.c | 11 +++++++++++ erts/emulator/drivers/win32/win_efile.c | 9 +++++++++ 5 files changed, 52 insertions(+) (limited to 'erts/emulator/drivers') diff --git a/erts/emulator/drivers/common/efile_drv.c b/erts/emulator/drivers/common/efile_drv.c index d2b916000e..b64d27de68 100644 --- a/erts/emulator/drivers/common/efile_drv.c +++ b/erts/emulator/drivers/common/efile_drv.c @@ -53,6 +53,7 @@ #define FILE_IPREAD 27 #define FILE_ALTNAME 28 #define FILE_READ_LINE 29 +#define FILE_FDATASYNC 30 /* Return codes */ @@ -883,6 +884,15 @@ static void invoke_chdir(void *data) invoke_name(data, efile_chdir); } +static void invoke_fdatasync(void *data) +{ + struct t_data *d = (struct t_data *) data; + int fd = (int) d->fd; + + d->again = 0; + d->result_ok = efile_fdatasync(&d->errInfo, fd); +} + static void invoke_fsync(void *data) { struct t_data *d = (struct t_data *) data; @@ -1919,6 +1929,7 @@ file_async_ready(ErlDrvData e, ErlDrvThreadData data) case FILE_RMDIR: case FILE_CHDIR: case FILE_DELETE: + case FILE_FDATASYNC: case FILE_FSYNC: case FILE_TRUNCATE: case FILE_LINK: @@ -2209,6 +2220,18 @@ file_output(ErlDrvData e, char* buf, int count) goto done; } + case FILE_FDATASYNC: + { + d = EF_SAFE_ALLOC(sizeof(struct t_data)); + + d->fd = fd; + d->command = command; + d->invoke = invoke_fdatasync; + d->free = free_data; + d->level = 2; + goto done; + } + case FILE_FSYNC: { d = EF_SAFE_ALLOC(sizeof(struct t_data)); diff --git a/erts/emulator/drivers/common/erl_efile.h b/erts/emulator/drivers/common/erl_efile.h index 9aa941e550..6821a0e2ee 100644 --- a/erts/emulator/drivers/common/erl_efile.h +++ b/erts/emulator/drivers/common/erl_efile.h @@ -126,6 +126,7 @@ int efile_readdir(Efile_error* errInfo, char* name, int efile_openfile(Efile_error* errInfo, char* name, int flags, int* pfd, Sint64* pSize); void efile_closefile(int fd); +int efile_fdatasync(Efile_error* errInfo, int fd); int efile_fsync(Efile_error* errInfo, int fd); int efile_fileinfo(Efile_error* errInfo, Efile_info* pInfo, char *name, int info_for_link); diff --git a/erts/emulator/drivers/common/ram_file_drv.c b/erts/emulator/drivers/common/ram_file_drv.c index 4a39a156e6..d4e547ade6 100644 --- a/erts/emulator/drivers/common/ram_file_drv.c +++ b/erts/emulator/drivers/common/ram_file_drv.c @@ -35,6 +35,7 @@ #define RAM_FILE_TRUNCATE 14 #define RAM_FILE_PREAD 17 #define RAM_FILE_PWRITE 18 +#define RAM_FILE_FDATASYNC 19 /* other operations */ #define RAM_FILE_GET 30 @@ -558,6 +559,13 @@ static void rfile_command(ErlDrvData e, char* buf, int count) numeric_reply(f, 0); /* 0 is not used */ break; + case RAM_FILE_FDATASYNC: + if (f->flags == 0) + error_reply(f, EBADF); + else + reply(f, 1, 0); + break; + case RAM_FILE_FSYNC: if (f->flags == 0) error_reply(f, EBADF); diff --git a/erts/emulator/drivers/unix/unix_efile.c b/erts/emulator/drivers/unix/unix_efile.c index 1d094ee613..0cece76221 100644 --- a/erts/emulator/drivers/unix/unix_efile.c +++ b/erts/emulator/drivers/unix/unix_efile.c @@ -773,6 +773,17 @@ efile_closefile(int fd) close(fd); } +int +efile_fdatasync(Efile_error *errInfo, /* Where to return error codes. */ + int fd) /* File descriptor for file to sync data. */ +{ +#ifdef HAVE_FDATASYNC + return check_error(fdatasync(fd), errInfo); +#else + return efile_fsync(errInfo, fd); +#endif +} + int efile_fsync(Efile_error *errInfo, /* Where to return error codes. */ int fd) /* File descriptor for file to sync. */ diff --git a/erts/emulator/drivers/win32/win_efile.c b/erts/emulator/drivers/win32/win_efile.c index 89aaad31da..cdf3bb424c 100644 --- a/erts/emulator/drivers/win32/win_efile.c +++ b/erts/emulator/drivers/win32/win_efile.c @@ -763,6 +763,15 @@ int fd; /* File descriptor for file to close. */ CloseHandle((HANDLE) fd); } +int +efile_fdatasync(errInfo, fd) +Efile_error* errInfo; /* Where to return error codes. */ +int fd; /* File descriptor for file to sync. */ +{ + /* Not available in Windows, just call regular fsync */ + return efile_fsync(errInfo, fd); +} + int efile_fsync(errInfo, fd) Efile_error* errInfo; /* Where to return error codes. */ -- cgit v1.2.3 From 21a67b797e40df930b83bd407ffc165b3f4b91b2 Mon Sep 17 00:00:00 2001 From: Filipe David Manana Date: Mon, 26 Apr 2010 13:04:40 +0200 Subject: Add file:advise/4 - a wrapper to the POSIX syscall posix_fadvise Useful for informing the Operating System about the access pattern for a file's data, so that it can adapt the caching strategy to maximize disk IO performance. --- erts/emulator/drivers/common/efile_drv.c | 34 +++++++++++++++++++++++++++++ erts/emulator/drivers/common/erl_efile.h | 2 ++ erts/emulator/drivers/common/ram_file_drv.c | 9 ++++++++ erts/emulator/drivers/unix/unix_efile.c | 11 ++++++++++ erts/emulator/drivers/win32/win_efile.c | 9 ++++++++ 5 files changed, 65 insertions(+) (limited to 'erts/emulator/drivers') diff --git a/erts/emulator/drivers/common/efile_drv.c b/erts/emulator/drivers/common/efile_drv.c index b64d27de68..60ae4cb108 100644 --- a/erts/emulator/drivers/common/efile_drv.c +++ b/erts/emulator/drivers/common/efile_drv.c @@ -54,6 +54,7 @@ #define FILE_ALTNAME 28 #define FILE_READ_LINE 29 #define FILE_FDATASYNC 30 +#define FILE_FADVISE 31 /* Return codes */ @@ -358,6 +359,11 @@ struct t_data struct t_readdir_buf *first_buf; struct t_readdir_buf *last_buf; } read_dir; + struct { + Sint64 offset; + Sint64 length; + int advise; + } fadvise; } c; char b[1]; }; @@ -1647,6 +1653,18 @@ static void invoke_open(void *data) d->result_ok = status; } +static void invoke_fadvise(void *data) +{ + struct t_data *d = (struct t_data *) data; + int fd = (int) d->fd; + off_t offset = (off_t) d->c.fadvise.offset; + off_t length = (off_t) d->c.fadvise.length; + int advise = (int) d->c.fadvise.advise; + + d->again = 0; + d->result_ok = efile_fadvise(&d->errInfo, fd, offset, length, advise); +} + static void free_readdir(void *data) { struct t_data *d = (struct t_data *) data; @@ -1936,6 +1954,7 @@ file_async_ready(ErlDrvData e, ErlDrvThreadData data) case FILE_SYMLINK: case FILE_RENAME: case FILE_WRITE_INFO: + case FILE_FADVISE: reply(desc, d->result_ok, &d->errInfo); free_data(data); break; @@ -2355,6 +2374,21 @@ file_output(ErlDrvData e, char* buf, int count) goto done; } + case FILE_FADVISE: + { + d = EF_SAFE_ALLOC(sizeof(struct t_data)); + + d->fd = fd; + d->command = command; + d->invoke = invoke_fadvise; + d->free = free_data; + d->level = 2; + d->c.fadvise.offset = get_int64((uchar*) buf); + d->c.fadvise.length = get_int64(((uchar*) buf) + sizeof(Sint64)); + d->c.fadvise.advise = get_int32(((uchar*) buf) + 2 * sizeof(Sint64)); + goto done; + } + } /* diff --git a/erts/emulator/drivers/common/erl_efile.h b/erts/emulator/drivers/common/erl_efile.h index 6821a0e2ee..61684af6c9 100644 --- a/erts/emulator/drivers/common/erl_efile.h +++ b/erts/emulator/drivers/common/erl_efile.h @@ -151,3 +151,5 @@ int efile_altname(Efile_error* errInfo, char *name, int efile_link(Efile_error* errInfo, char* old, char* new); int efile_symlink(Efile_error* errInfo, char* old, char* new); int efile_may_openfile(Efile_error* errInfo, char *name); +int efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset, Sint64 length, + int advise); diff --git a/erts/emulator/drivers/common/ram_file_drv.c b/erts/emulator/drivers/common/ram_file_drv.c index d4e547ade6..abedcc933a 100644 --- a/erts/emulator/drivers/common/ram_file_drv.c +++ b/erts/emulator/drivers/common/ram_file_drv.c @@ -46,6 +46,8 @@ #define RAM_FILE_UUENCODE 35 /* uuencode file */ #define RAM_FILE_UUDECODE 36 /* uudecode file */ #define RAM_FILE_SIZE 37 /* get file size */ +#define RAM_FILE_ADVISE 38 /* predeclare the access + * pattern for file data */ /* possible new operations include: DES_ENCRYPT DES_DECRYPT @@ -693,6 +695,13 @@ static void rfile_command(ErlDrvData e, char* buf, int count) case RAM_FILE_UUDECODE: /* uudecode file */ ram_file_uudecode(f); break; + + case RAM_FILE_ADVISE: + if (f->flags == 0) + error_reply(f, EBADF); + else + reply(f, 1, 0); + break; } /* * Ignore anything else -- let the caller hang. diff --git a/erts/emulator/drivers/unix/unix_efile.c b/erts/emulator/drivers/unix/unix_efile.c index 0cece76221..ea016526ef 100644 --- a/erts/emulator/drivers/unix/unix_efile.c +++ b/erts/emulator/drivers/unix/unix_efile.c @@ -1448,3 +1448,14 @@ efile_symlink(Efile_error* errInfo, char* old, char* new) return check_error(symlink(old, new), errInfo); #endif } + +int +efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset, + Sint64 length, int advise) +{ +#ifdef HAVE_POSIX_FADVISE + return check_error(posix_fadvise(fd, offset, length, advise), errInfo); +#else + return check_error(0, errInfo); +#endif +} diff --git a/erts/emulator/drivers/win32/win_efile.c b/erts/emulator/drivers/win32/win_efile.c index cdf3bb424c..06850b4945 100644 --- a/erts/emulator/drivers/win32/win_efile.c +++ b/erts/emulator/drivers/win32/win_efile.c @@ -1433,3 +1433,12 @@ efile_symlink(Efile_error* errInfo, char* old, char* new) errno = ENOTSUP; return check_error(-1, errInfo); } + +int +efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset, + Sint64 length, int advise) +{ + /* posix_fadvise is not available on Windows, do nothing */ + errno = ERROR_SUCCESS; + return check_error(0, errInfo); +} -- cgit v1.2.3