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preliminary use of the config system for some settings

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* backend.filehandles maximum filehandles used
 * backend.mmap_window_size mapping window start size
 * backend.as_limit address space limit

This needs to be changed to use the lumieraorg_configuration interface.
This commit is contained in:
Christian Thaeter 2008-11-07 19:05:58 +01:00
parent 2a0b5dca5e
commit 5bbe80b370
3 changed files with 75 additions and 25 deletions
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29
doc/devel/config_guide.txt
View file

@ -78,3 +78,32 @@ Sensible defaults are initialized at installation time.
plugin.path
I/O Backend
-----------
File handling
~~~~~~~~~~~~~
How many filehandles the backend shall use [approx 2/3 of all available]
backend.filehandles
Memory mapped Files
~~~~~~~~~~~~~~~~~~~
Address space limit (memory mapping)
Defaults:
3GiB on 32 bit arch
192TiB on 64 bit arch
backend.as_limit
Default start size for mmaping windows.
128MB on 32 bit arch
2GB on 64 bit arch
backend.mmap_window_size

39
src/backend/backend.c
View file

@ -19,7 +19,10 @@
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "lib/safeclib.h"
#include "backend/backend.h"
#include "backend/config.h"
#include "backend/filehandlecache.h"
#include "backend/filedescriptor.h"
#include "backend/mmapcache.h"
@ -56,30 +59,38 @@ lumiera_backend_init (void)
TODO ("add config options to override following defaults");
/* roughly 2/3 of all availables filehandles are managed by the backend */
int max_entries = (sysconf (_SC_OPEN_MAX)-10)*2/3;
INFO (backend, "using %d filehandles", max_entries);
const char* filehandles = lumiera_tmpbuf_snprintf (SIZE_MAX,
"backend.filehandles = %d",
/* roughly 2/3 of all availables filehandles are managed by the backend */
(sysconf (_SC_OPEN_MAX)-10)*2/3);
lumiera_config_setdefault (filehandles);
long long max_entries;
lumiera_config_number_get ("backend.filehandles", &max_entries);
lumiera_filehandlecache_new (max_entries);
struct rlimit as_limit;
getrlimit (RLIMIT_AS, &as_limit);
if (as_limit.rlim_cur == RLIM_INFINITY)
{
#if SIZE_MAX <= 4294967295UL
INFO (backend, "address space not limited, backend will mmap at most 1.5GiB");
as_limit.rlim_cur = 1610612736U;
lumiera_config_setdefault ("backend.as_limit = 3221225469");
#else
INFO (backend, "address space not limited, backend will mmap at most 192TiB");
as_limit.rlim_cur = 211106232532992U;
lumiera_config_setdefault ("backend.as_limit = 211106232532992");
#endif
struct rlimit as_rlimit;
getrlimit (RLIMIT_AS, &as_rlimit);
long long as_limit = (long long)as_rlimit.rlim_cur;
if (as_rlimit.rlim_cur == RLIM_INFINITY)
{
lumiera_config_number_get ("backend.as_limit", &as_limit);
}
else
{
INFO (backend, "address space limited to %luMiB", as_limit.rlim_cur/1024/1024);
INFO (backend, "address space limited to %luMiB", as_rlimit.rlim_cur/1024/1024);
}
lumiera_mmapcache_new (as_limit.rlim_cur);
lumiera_mmapcache_new (as_limit);
return 0;
}

32
src/backend/mmap.c
View file

@ -23,6 +23,7 @@
#include "backend/mmap.h"
#include "backend/mmapcache.h"
#include "backend/config.h"
#include <unistd.h>
#include <sys/mman.h>
@ -46,16 +47,6 @@ LUMIERA_ERROR_DEFINE (MMAP_SPACE, "Address space exhausted");
*
*/
/**
* default size for the mmaping window
* 128MB on 32 bit arch
* 2GB on 64 bit arch
*/
#if SIZE_MAX <= 4294967295U
static size_t mmap_window_size = 134217728UL;
#else
static size_t mmap_window_size = 2147483648UL;
#endif
LumieraMMap
lumiera_mmap_init (LumieraMMap self, LumieraFile file, LList acquirer, off_t start, size_t size, size_t chunksize)
@ -69,6 +60,25 @@ lumiera_mmap_init (LumieraMMap self, LumieraFile file, LList acquirer, off_t sta
REQUIRE (start >= 0);
REQUIRE (size);
static int once = 0;
if (!once)
{
once = 1;
/**
* default size for the mmaping window
* 128MB on 32 bit arch
* 2GB on 64 bit arch
*/
#if SIZE_MAX <= 4294967295U
lumiera_config_setdefault ("backend.mmap_window_size = 134217728");
#else
lumiera_config_setdefault ("backend.mmap_window_size = 2147483648");
#endif
}
long long mmap_window_size = 0;
lumiera_config_number_get ("backend.mmap_window_size", &mmap_window_size);
LumieraFiledescriptor descriptor = file->descriptor;
int fd = lumiera_file_handle_acquire (file);
@ -139,7 +149,7 @@ lumiera_mmap_init (LumieraMMap self, LumieraFile file, LList acquirer, off_t sta
goto ewrite;
}
}
else if (length < mmap_window_size)
else if (length < (size_t)mmap_window_size)
length = mmap_window_size;
if ((descriptor->flags & O_ACCMODE) == O_RDONLY)