From: Petr Vorel <pvorel@suse.cz>
To: ltp@lists.linux.it
Subject: Re: [LTP] [PATCH 1/1] zram01.sh: Fill the filesystem with a single dd call
Date: Mon, 9 Nov 2026 20:38:09 +0100 [thread overview]
Message-ID: <20261109193809.GA669592@pevik> (raw)
In-Reply-To: <20261109193344.669217-1-pvorel@suse.cz>
Hi,
More data how it's slow on the current implementation (without this patch):
We have these filesystems:
zram01 6 TINFO: mount /dev/zram0 (ext2)
zram01 6 TINFO: mount /dev/zram1 (ext3)
zram01 6 TINFO: mount /dev/zram2 (ext4)
zram01 6 TINFO: mount /dev/zram3 (xfs)
zram01 6 TINFO: mount /dev/zram4 (btrfs)
zram01 6 TINFO: mount /dev/zram5 (vfat)
For some reason only for XFS and Btrfs test use bigger disk size and therefore
bigger memory limit (I haven't investigated, but we use the same lzo alg. for
all of them):
zram01 3 TINFO: set disk size to zram device(s)
zram01 3 TINFO: /sys/block/zram0/disksize = '26214400'
zram01 3 TINFO: /sys/block/zram1/disksize = '26214400'
zram01 3 TINFO: /sys/block/zram2/disksize = '26214400'
zram01 3 TINFO: /sys/block/zram3/disksize = '314572800'
zram01 3 TINFO: /sys/block/zram4/disksize = '402653184'
zram01 3 TINFO: /sys/block/zram5/disksize = '26214400'
zram01 3 TPASS: test succeeded
zram01 4 TINFO: set memory limit to zram device(s)
zram01 4 TINFO: /sys/block/zram0/mem_limit = '25M'
zram01 4 TINFO: /sys/block/zram1/mem_limit = '25M'
zram01 4 TINFO: /sys/block/zram2/mem_limit = '25M'
zram01 4 TINFO: /sys/block/zram3/mem_limit = '300M'
zram01 4 TINFO: /sys/block/zram4/mem_limit = '384M'
zram01 4 TINFO: /sys/block/zram5/mem_limit = '25M'
And therefore filling it (test 7) fails on Btrfs:
zram01 7 TINFO: filling zram0 (it can take long time)
zram01 7 TPASS: zram0 was filled with '24724' KB
zram01 7 TINFO: /sys/block/zram0/mm_stat
24145920 24006 69632 26214400 69632 5877 0
zram01 7 TINFO: mem_used_total: 69632
zram01 7 TPASS: compression ratio: 363.58:1
zram01 7 TINFO: filling zram1 (it can take long time)
zram01 7 TPASS: zram1 was filled with '20628' KB
zram01 7 TINFO: /sys/block/zram1/mm_stat
26144768 184936 577536 26214400 577536 6079 0
zram01 7 TINFO: mem_used_total: 577536
zram01 7 TPASS: compression ratio: 36.57:1
zram01 7 TINFO: filling zram2 (it can take long time)
zram01 7 TPASS: zram2 was filled with '20132' KB
zram01 7 TINFO: /sys/block/zram2/mm_stat
24580096 31639 122880 26214400 122880 5774 0
zram01 7 TINFO: mem_used_total: 122880
zram01 7 TPASS: compression ratio: 167.76:1
zram01 7 TINFO: filling zram3 (it can take long time)
zram01 7 TPASS: zram3 was filled with '285128' KB
zram01 7 TINFO: /sys/block/zram3/mm_stat
298844160 100509 249856 314572800 253952 72411 0
zram01 7 TINFO: mem_used_total: 249856
zram01 7 TPASS: compression ratio: 1168.55:1
zram01 7 TINFO: filling zram4 (it can take long time)
Interesting enough, ~1/4 smaller XFS is ok, Btrfs is probably too big.
Of course nothing problematic in dmesg, IMHO it's just long (2h15m while still
filling zram4 btrfs).
And yes, looking into logs suggest testing each filesystem separately would help
to read the logs.
Kind regards,
Petr
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Mailing list info: https://lists.linux.it/listinfo/ltp
next prev parent reply other threads:[~2026-11-09 19:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-09 19:33 [LTP] [PATCH 1/1] zram01.sh: Fill the filesystem with a single dd call Petr Vorel
2026-11-09 19:38 ` Petr Vorel [this message]
2026-11-10 9:47 ` Cyril Hrubis
2026-11-10 11:18 ` Petr Vorel
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