Date: Wed, 4 Nov 2009 13:05:56 GMT From: Alexander Motin <mav@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 170158 for review Message-ID: <200911041305.nA4D5u1X031733@repoman.freebsd.org>
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http://p4web.freebsd.org/chv.cgi?CH=170158 Change 170158 by mav@mav_mavtest on 2009/11/04 13:05:18 Do not unarm callout on request completion and change slot selection algorithm as done in ahci(4). This saves some CPU time on high request rates. Affected files ... .. //depot/projects/scottl-camlock/src/sys/dev/siis/siis.c#14 edit Differences ... ==== //depot/projects/scottl-camlock/src/sys/dev/siis/siis.c#14 (text+ko) ==== @@ -641,6 +641,7 @@ for (i = 0; i < SIIS_MAX_SLOTS; i++) { struct siis_slot *slot = &ch->slot[i]; + callout_drain(&slot->timeout); if (slot->dma.data_map) { bus_dmamap_destroy(ch->dma.data_tag, slot->dma.data_map); slot->dma.data_map = NULL; @@ -838,15 +839,11 @@ mtx_assert(&ch->mtx, MA_OWNED); /* Choose empty slot. */ tag = ch->lastslot; - do { - tag++; - if (tag >= SIIS_MAX_SLOTS) + while (ch->slot[tag].state != SIIS_SLOT_EMPTY) { + if (++tag >= SIIS_MAX_SLOTS) tag = 0; - if (ch->slot[tag].state == SIIS_SLOT_EMPTY) - break; - } while (tag != ch->lastslot); - if (ch->slot[tag].state != SIIS_SLOT_EMPTY) - device_printf(ch->dev, "ALL SLOTS BUSY!\n"); + KASSERT(tag != ch->lastslot, ("siis: ALL SLOTS BUSY!")); + } ch->lastslot = tag; /* Occupy chosen slot. */ slot = &ch->slot[tag]; @@ -999,6 +996,9 @@ struct siis_channel *ch = device_get_softc(dev); mtx_assert(&ch->mtx, MA_OWNED); + /* Check for stale timeout. */ + if (slot->state < SIIS_SLOT_RUNNING) + return; device_printf(dev, "Timeout on slot %d\n", slot->slot); device_printf(dev, "%s is %08x ss %08x rs %08x es %08x sts %08x serr %08x\n", __func__, ATA_INL(ch->r_mem, SIIS_P_IS), ATA_INL(ch->r_mem, SIIS_P_SS), ch->rslots, @@ -1024,8 +1024,6 @@ union ccb *ccb = slot->ccb; mtx_assert(&ch->mtx, MA_OWNED); - /* Cancel command execution timeout */ - callout_stop(&slot->timeout); bus_dmamap_sync(ch->dma.work_tag, ch->dma.work_map, BUS_DMASYNC_POSTWRITE); /* Read result registers to the result struct
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