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Back out rev 1.4. The advertised 64K limit on transfers only applies when

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using 64bit S/G entries.  With this reverted, we are seeing >92MB/sec reads
and >42MB/sec writes on a RAID-5 container.
This commit is contained in:
Scott Long 2001-03-21 21:53:09 +00:00
parent 9575fb2f65
commit d5fd2abf4f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=74604
1 changed files with 11 additions and 4 deletions
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15
sys/dev/aac/aac_disk.c
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@ -219,6 +219,8 @@ static int
aac_disk_attach(device_t dev)
{
struct aac_disk *sc = (struct aac_disk *)device_get_softc(dev);
int sgspace;
int maxsg;
debug_called(4);
@ -256,11 +258,16 @@ aac_disk_attach(device_t dev)
disks_registered++;
#endif
/*
* The adapters seem to have a 64K size limit on the max I/O size. Set
* our size on accordance.
/*
* We can calculate the maximum number of s/g entries based on the size of the
* FIB and the command structures packed within it.
*/
sc->ad_dev_t->si_iosize_max = 65536;
sgspace = (sizeof(struct aac_fib) - sizeof(struct aac_fib_header) -
imax(sizeof(struct aac_blockwrite), sizeof(struct aac_blockread)));
maxsg = (sgspace - sizeof(struct aac_sg_table)) / sizeof(struct aac_sg_entry);
/* set the maximum I/O size to the theoretical worst maximum allowed by the S/G list size */
sc->ad_dev_t->si_iosize_max = (maxsg - 1) * PAGE_SIZE;
return (0);
}