From mboxrd@z Thu Jan 1 00:00:00 1970 From: Breno Leitao Subject: Re: [PATCH] blk-iocost: initialize rqos before accessing it Date: Sun, 26 Feb 2023 07:59:48 +0000 Message-ID: <3130cb3e-eaca-04c2-ad97-b32ffddad397@debian.org> References: <20230224160714.172884-1-leitao@debian.org> <20230224185126.bxkreilofbp2t4on@blackpad> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Content-Language: en-US In-Reply-To: <20230224185126.bxkreilofbp2t4on@blackpad> List-ID: Content-Type: text/plain; charset="iso-8859-1"; format="flowed" To: =?UTF-8?Q?Michal_Koutn=c3=bd?= Cc: axboe@kernel.dk, tj@kernel.org, josef@toxicpanda.com, cgroups@vger.kernel.org, linux-block@vger.kernel.org, aherrmann@suse.de, linux-kernel@vger.kernel.org, hch@lst.de, leit@fb.com Hello Michal, On 2/24/23 18:51, Michal Koutn=C3=BD wrote: >> blk_iocost_init (include/asm-generic/qspinlock.h:128 >> include/linux/spinlock.h:203 >> include/linux/spinlock_api_smp.h:158 >> include/linux/spinlock.h:400 >> block/blk-iocost.c:2884) >> ioc_qos_write (block/blk-iocost.c:3198) >> ? kretprobe_perf_func (kernel/trace/trace_kprobe.c:1566) >> ? kernfs_fop_write_iter (include/linux/slab.h:584 fs/kernfs/file.c:311) >> ? __kmem_cache_alloc_node (mm/slab.h:? mm/slub.c:3452 mm/slub.c:3491) >> ? _copy_from_iter (arch/x86/include/asm/uaccess_64.h:46 >> arch/x86/include/asm/uaccess_64.h:52 >> lib/iov_iter.c:183 lib/iov_iter.c:628) >> ? kretprobe_dispatcher (kernel/trace/trace_kprobe.c:1693) >> cgroup_file_write (kernel/cgroup/cgroup.c:4061) >> kernfs_fop_write_iter (fs/kernfs/file.c:334) >> vfs_write (include/linux/fs.h:1849 fs/read_write.c:491 >> fs/read_write.c:584) >> ksys_write (fs/read_write.c:637) >> do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) >> entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) >=20 > BTW, out of curiosity what tool did you use to list stack with line > numbers? I use the decode_stacktrace.sh from kernel's scripts directory. You=20 basically pipe the stack to it, and call it passing the vmlinux file. It is=20 incredible handy. https://elixir.bootlin.com/linux/latest/source/scripts/decode_stacktrace.sh Thanks for the review, Breno