2013/4/7, Max Filippov <jcmvb...@gmail.com>: > On Sun, Apr 7, 2013 at 4:36 AM, Namjae Jeon <linkinj...@gmail.com> wrote: >> >> >> 2013/4/6 Max Filippov <jcmvb...@gmail.com> >>> >>> Hi Namjae, >>> >>> On Fri, Apr 5, 2013 at 11:57 AM, Namjae Jeon <linkinj...@gmail.com> >>> wrote: >>> > Hi. Max. >>> > >>> > I have a question. >>> > Your mmc host driver set to host->max_discard_to by some value instead >>> > of not zero ? >>> >>> I believe it's zero, because the only place where I can see it >>> initialized >>> (sdhci_add_host in the drivers/mmc/host/sdhci.c) is not built in my >>> configuration. >>> >> -> sorry for private mail. There is confusing to me about your previous >> mail. >> I think that max_discard_sectors is set to 0xFFFFFFFF(UINT_MAX). >> because mmc core set to it by UINT_MAX when host-<max_discard_to is zero. >> So I guess it can try to be merged to over 4GB size. >> >> unsigned int mmc_calc_max_discard(struct mmc_card *card) >> { >> struct mmc_host *host = card->host; >> unsigned int max_discard, max_trim; >> >> if (!host->max_discard_to) >> return UINT_MAX; ==> It should be UINT_MAX >> 9; >> >> unfortunely, I don't have mmc device and card had over 4GB size. >> So If you agree, Could you try to test after changing above code >> UINT_MAX >> => UINT_MAX >> 9 ? > > This fixes the issue too. Requests do not merge, although > attempt_plug_merge > returns ELEVATOR_BACK_MERGE. Okay, Thanks for your test. As I guess, this issue is caused from max discards setting of mmc core. I will try to commit this patch to mmc driver.
Thanks Max. > > -- > Thanks. > -- Max > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/