lightnvm: pblk: fix write amplificiation calculation
authorHans Holmberg <hans.holmberg@cnexlabs.com>
Tue, 9 Oct 2018 11:11:50 +0000 (13:11 +0200)
committerJens Axboe <axboe@kernel.dk>
Tue, 9 Oct 2018 14:25:07 +0000 (08:25 -0600)
When the user data counter exceeds 32 bits, the write amplification
calculation does not provide the right value. Fix this by using
div64_u64 in stead of div64.

Fixes: 76758390f83e ("lightnvm: pblk: export write amplification counters to sysfs")
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/lightnvm/pblk-sysfs.c

index 9fc3dfa168b4bb40f3b43043c02200c4aa6a1b9d..e56eeeeb914ede990cfae55607a634a2b4e2b013 100644 (file)
@@ -337,7 +337,6 @@ static ssize_t pblk_get_write_amp(u64 user, u64 gc, u64 pad,
 {
        int sz;
 
-
        sz = snprintf(page, PAGE_SIZE,
                        "user:%lld gc:%lld pad:%lld WA:",
                        user, gc, pad);
@@ -349,7 +348,7 @@ static ssize_t pblk_get_write_amp(u64 user, u64 gc, u64 pad,
                u32 wa_frac;
 
                wa_int = (user + gc + pad) * 100000;
-               wa_int = div_u64(wa_int, user);
+               wa_int = div64_u64(wa_int, user);
                wa_int = div_u64_rem(wa_int, 100000, &wa_frac);
 
                sz += snprintf(page + sz, PAGE_SIZE - sz, "%llu.%05u\n",