FS/XFS testing framework
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From: "Darrick J. Wong" <djwong@kernel.org>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: Eryu Guan <eguan@redhat.com>, Zorro Lang <zlang@kernel.org>,
	fstests@vger.kernel.org,
	Kent Overstreet <kent.overstreet@linux.dev>
Subject: Re: [PATCH] generic/558: limit the number of spawned subprocesses
Date: Wed, 12 Jul 2023 18:48:37 -0700	[thread overview]
Message-ID: <20230713014837.GG11442@frogsfrogsfrogs> (raw)
In-Reply-To: <2bb7705c-9a1a-6185-4554-9121e5cda710@redhat.com>

Mikulas, does this solve the forkbomb problem?

--D

diff --git a/tests/generic/558 b/tests/generic/558
index 4e22ce656b..de5c28d00d 100755
--- a/tests/generic/558
+++ b/tests/generic/558
@@ -39,15 +39,21 @@ _scratch_mkfs_sized $((1024 * 1024 * 1024)) >>$seqres.full 2>&1
 _scratch_mount
 
 i=0
-free_inode=`_get_free_inode $SCRATCH_MNT`
-file_per_dir=1000
-loop=$((free_inode / file_per_dir + 1))
+free_inodes=$(_get_free_inode $SCRATCH_MNT)
+nr_cpus=$(( $($here/src/feature -o) * 4 * LOAD_FACTOR ))
+echo "free inodes: $free_inodes nr_cpus: $nr_cpus" >> $seqres.full
+
+if ((free_inodes <= nr_cpus)); then
+	nr_cpus=1
+	files_per_dir=$free_inodes
+else
+	files_per_dir=$(( (free_inodes + nr_cpus - 1) / nr_cpus ))
+fi
 mkdir -p $SCRATCH_MNT/testdir
 
 echo "Create $((loop * file_per_dir)) files in $SCRATCH_MNT/testdir" >>$seqres.full
-while [ $i -lt $loop ]; do
-	create_file $SCRATCH_MNT/testdir $file_per_dir $i >>$seqres.full 2>&1 &
-	let i=$i+1
+for ((i = 0; i < nr_cpus; i++)); do
+	create_file $SCRATCH_MNT/testdir $files_per_dir $i >>$seqres.full 2>&1 &
 done
 wait
 

  parent reply	other threads:[~2023-07-13  1:48 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-11 15:51 [PATCH] generic/558: limit the number of spawned subprocesses Mikulas Patocka
2023-07-11 23:44 ` Darrick J. Wong
2023-07-12  1:09   ` Kent Overstreet
2023-07-12  5:15     ` Amir Goldstein
2023-07-12 10:10     ` Mikulas Patocka
2023-07-12 14:52       ` Kent Overstreet
2023-07-12 17:59         ` Mikulas Patocka
2023-07-12 18:35           ` Kent Overstreet
2023-07-12  9:57   ` Mikulas Patocka
2023-07-12 22:05     ` Darrick J. Wong
2023-07-12 18:40 ` Zorro Lang
2023-07-13  1:44   ` Theodore Ts'o
2023-07-13  1:48 ` Darrick J. Wong [this message]
2023-07-13 15:08   ` Mikulas Patocka

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