From: Al Viro <viro@zeniv.linux.org.uk>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Eric Biggers <ebiggers@google.com>, linux-fsdevel@vger.kernel.org
Subject: interesting breakage in ltp fanotify10
Date: Sun, 22 Jun 2025 22:51:40 +0100 [thread overview]
Message-ID: <20250622215140.GX1880847@ZenIV> (raw)
LTP 6763a3650734 "syscalls/fanotify10: Add test cases for evictable
ignore mark" has an interesting effect on boxen where FANOTIFY is not
enabled. The thing is, tst_brk() ends up calling ->cleanup(). See the
problem?
SAFE_FILE_PRINTF(CACHE_PRESSURE_FILE, "%d", old_cache_pressure);
is executed, even though
SAFE_FILE_SCANF(CACHE_PRESSURE_FILE, "%d", &old_cache_pressure);
/* Set high priority for evicting inodes */
SAFE_FILE_PRINTF(CACHE_PRESSURE_FILE, "500");
hadn't been.
Result: fanotify10 on such kernel configs ends up zeroing
/proc/sys/vm/vfs_cache_pressure. How much does it confuse the rest of
LTP is an interesting question; it *does* have a fun effect on subsequent
xfstests run - generic/622 gets confused. No other failures get reported
by xfstests, for whatever little it's worth...
Arguably, there's an xfstests bug as well - since generic/622
depends upon vfs_cache_pressure being non-zero, it ought to set it
to something sane.
next reply other threads:[~2025-06-22 21:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-22 21:51 Al Viro [this message]
2025-06-23 7:24 ` interesting breakage in ltp fanotify10 Amir Goldstein
2025-06-23 14:45 ` Al Viro
2025-06-23 15:19 ` Amir Goldstein
2025-06-23 15:38 ` Al Viro
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