diff options
| author | ps <ps@FreeBSD.org> | 2000-10-17 10:05:49 +0000 |
|---|---|---|
| committer | ps <ps@FreeBSD.org> | 2000-10-17 10:05:49 +0000 |
| commit | c71ac689e04ce39d113325e3854477539dae464c (patch) | |
| tree | 331cd4cbe2e1e3d9d7734fa4fce3e6a5554d434c /sys/cam | |
| parent | 26207dd1489dfcba9ad2215401292904446e000a (diff) | |
| download | FreeBSD-src-c71ac689e04ce39d113325e3854477539dae464c.zip FreeBSD-src-c71ac689e04ce39d113325e3854477539dae464c.tar.gz | |
Implement write combining for crashdumps. This is useful when
write caching is disabled on both SCSI and IDE disks where large
memory dumps could take up to an hour to complete.
Taking an i386 scsi based system with 512MB of ram and timing (in
seconds) how long it took to complete a dump, the following results
were obtained:
Before: After:
WCE TIME WCE TIME
------------------ ------------------
1 141.820972 1 15.600111
0 797.265072 0 65.480465
Obtained from: Yahoo!
Reviewed by: peter
Diffstat (limited to 'sys/cam')
| -rw-r--r-- | sys/cam/scsi/scsi_da.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c index cc5ada2..45d3d76 100644 --- a/sys/cam/scsi/scsi_da.c +++ b/sys/cam/scsi/scsi_da.c @@ -634,7 +634,9 @@ dadump(dev_t dev) long blkcnt; vm_offset_t addr; struct ccb_scsiio csio; + int dumppages = MAXDUMPPGS; int error; + int i; /* toss any characters present prior to dump */ while (cncheckc() != -1) @@ -659,12 +661,17 @@ dadump(dev_t dev) blkcnt = howmany(PAGE_SIZE, secsize); while (num > 0) { - void *va; + caddr_t va; - if (is_physical_memory(addr)) { - va = pmap_kenter_temporary(trunc_page(addr)); - } else { - va = pmap_kenter_temporary(trunc_page(0)); + if ((num / blkcnt) < dumppages) + dumppages = num / blkcnt; + + for (i = 0; i < dumppages; ++i) { + vm_offset_t a = addr + (i * PAGE_SIZE); + if (is_physical_memory(a)) + va = pmap_kenter_temporary(trunc_page(a), i); + else + va = pmap_kenter_temporary(trunc_page(0), i); } xpt_setup_ccb(&csio.ccb_h, periph->path, /*priority*/1); @@ -677,9 +684,9 @@ dadump(dev_t dev) /*byte2*/0, /*minimum_cmd_size*/ softc->minimum_cmd_size, blknum, - blkcnt, + blkcnt * dumppages, /*data_ptr*/(u_int8_t *) va, - /*dxfer_len*/blkcnt * secsize, + /*dxfer_len*/blkcnt * secsize * dumppages, /*sense_len*/SSD_FULL_SIZE, DA_DEFAULT_TIMEOUT * 1000); xpt_polled_action((union ccb *)&csio); @@ -706,9 +713,9 @@ dadump(dev_t dev) } /* update block count */ - num -= blkcnt; - blknum += blkcnt; - addr += PAGE_SIZE; + num -= blkcnt * dumppages; + blknum += blkcnt * dumppages; + addr += PAGE_SIZE * dumppages; /* operator aborting dump? */ if (cncheckc() != -1) |
