On 12/1/11, Tao Ma <tm@xxxxxx> wrote: > On 12/01/2011 04:19 PM, Kyungmin Park wrote: >> On 12/1/11, Tao Ma <tm@xxxxxx> wrote: >>> Hi Kyungmin, >>> On 12/01/2011 03:00 PM, Kyungmin Park wrote: >>>> From: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> >>>> >>>> Now trim information doesn't stored at disk so every boot time. it's >>>> cleared. >>>> and do the trim all disk groups. >>>> But assume that it's already trimmed at previous time so don't need to >>>> trim it again. So set the intial state as trimmed. >>> sorry, I don't get your meaning here. >>> Why can we assume that the group is already trimmed since it isn't >>> stored in the disk? >> To avoid the first time trim operation. >> Every boot time. run the fitrim then it trims all block groups again. >> but it's already done at previous time. so don't need to trim it >> again. >> Doesn't make sense? I think it's not designed behavior. > You make the assumption that we run the fitrim every time at boot time. > But what if the user don't run it at all? I guess "run fitrim during > boot" is your firmware's behaviour and it isn't an assumption for all > the other users. > > Having said that, this flag will be cleared whenever some > blocks/clusters are freed. So maybe it doesn't matter for setting this > flag during the group initialization. Right, I hope trim the real updated blocks only. Thank you, Kyungmin Park > > Thanks > Tao >> >> In your patch at http://patchwork.ozlabs.org/patch/102918/ >> >> with the patch: >> [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a >> real 0m5.625s >> user 0m0.000s >> sys 0m1.269s >> [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a >> real 0m0.002s >> user 0m0.000s >> sys 0m0.001s >> [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a >> real 0m0.002s >> user 0m0.000s >> sys 0m0.001s >> >> After reboot. it maybe become below >> >> [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a >> real 0m0.002s >> user 0m0.000s >> sys 0m0.001s >> [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a >> real 0m0.002s >> user 0m0.000s >> sys 0m0.001s >> [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a >> real 0m0.002s >> user 0m0.000s >> sys 0m0.001s >> >> Thank you, >> Kyungmin Park >>> >>> Thanks >>> Tao >>>> >>>> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> >>>> --- >>>> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c >>>> index e2d8be8..97ef342 100644 >>>> --- a/fs/ext4/mballoc.c >>>> +++ b/fs/ext4/mballoc.c >>>> @@ -1098,6 +1098,12 @@ int ext4_mb_init_group(struct super_block *sb, >>>> ext4_group_t group) >>>> goto err; >>>> } >>>> mark_page_accessed(page); >>>> + >>>> + /* >>>> + * TRIM information is not stored at disk so set the initial >>>> + * state as trimmed. Since previous time it's already trimmed all >>>> + */ >>>> + EXT4_MB_GRP_SET_TRIMMED(this_grp); >>>> err: >>>> ext4_mb_put_buddy_page_lock(&e4b); >>>> return ret; >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
