[LU-5750] lu_htable_order() overwrites module option lu_cache_nr

• Status: Open
• Project: Lustre
• Type: Bug
• Priority: Minor
• Reporter: Isaac Huang (Inactive)
• Assignee: Isaac Huang (Inactive)
• Resolution: Unresolved
• Labels: zfs
• Severity: 3

Description

Module parameter lu_cache_nr is always overwritten by lu_htable_order(), so only the default can be used:

[isaac@oyster]% sudo modprobe obdclass lu_cache_nr=-1
[isaac@oyster]% cat /sys/module/obdclass/parameters/lu_cache_nr
-1
[isaac@oyster]% sudo mount -t lustre test/test /mnt/lustre
[isaac@oyster]% cat /sys/module/obdclass/parameters/lu_cache_nr
10240

Comments

[Andreas Dilger]

Looks like this would be enough:

        if (strcmp(top->ld_type->ldt_name, LUSTRE_OSD_ZFS_NAME) == 0) {
                lu_cache_percent = 1;
                if (lu_cache_nr == LU_CACHE_NR_UNLIMITED)
                        lu_cache_nr = LU_CACHE_NR_ZFS_LIMIT;
                return LU_SITE_BITS_MIN;
        }

[Isaac Huang (Inactive)]

It seemed that with the code above, if user sets lu_cache_nr=LU_CACHE_NR_UNLIMITED (e.g. to work around LU-5747), it'd still get overwritten as LU_CACHE_NR_ZFS_LIMIT.