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Do not use the Linux mremap() call. Use the same strategy for xMremap() as on OSX instead.

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FossilOrigin-Name: 5ed8ad780c991d2ca44003ee84350fb5e95ad58e
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dan
2013-03-21 14:47:47 +00:00
parent d306e1a3a1
commit c71b45e619
3 changed files with 13 additions and 31 deletions
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30
src/os_unix.c
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@@ -4478,16 +4478,12 @@ static int unixMremap(
** it is possible to create a mapping larger than the file on disk and
** extend the file on disk later on.
**
** Exploit this on OSX to reduce the number of munmap()/mmap() calls
** if the file size is changing. In this case all mappings are rounded
** up to the nearest 4MB. And if a new mapping is requested that has the
** same rounded size as an old mapping, the old mapping can simply be
** reused as is.
**
** It would be possible to do the above on Linux too. However, Linux has
** the non-standard mremap() call to resize existing mappings, which can
** be used instead. */
#if defined(__APPLE__)
** Exploit this on Linux and OSX to reduce the number of munmap()/mmap()
** calls required if the file size is changing. In this case all mappings
** are rounded up to the nearest 4MB. And if a new mapping is requested
** that has the same rounded size as an old mapping, the old mapping can
** be reused as is. */
#if defined(__APPLE__) || defined(__linux__)
nNewRnd = ROUNDUP(nNew, 4096*1024);
nOldRnd = ROUNDUP(nOld, 4096*1024);
#else
@@ -4502,20 +4498,6 @@ static int unixMremap(
}
#endif
/* On Linux, if there is both an old and new mapping, resize the old
** mapping using the non-standard mremap() call. */
#if defined(_GNU_SOURCE) && defined(__linux__)
if( nNewRnd && nOldRnd ){
void *pOld = *ppMap;
*ppMap = pNew = mremap(pOld, nOldRnd, nNewRnd, MREMAP_MAYMOVE);
if( pNew==MAP_FAILED ){
*ppMap = 0;
return SQLITE_IOERR_MREMAP;
}
return SQLITE_OK;
}
#endif
/* If we get this far, unmap any old mapping. */
if( nOldRnd!=0 ){
void *pOld = *ppMap;