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Wed, 02 Sep 2026 15:31:45 +0000 X-Mizu-Trace-ID: 8935c3cd496893e1 X-Migadu-Flow: FLOW_OUT Date: Wed, 2 Sep 2026 08:31:44 -0700 From: Shakeel Butt To: Kefeng Wang Cc: brauner@kernel.org, djwong@kernel.org, cem@kernel.org, akpm@linux-foundation.org, vbabka@kernel.org, surenb@google.com, mhocko@suse.com, brendan.jackman@linux.dev, hannes@cmpxchg.org, ziy@nvidia.com, david@kernel.org, qi.zheng@linux.dev, ljs@kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/4] mm: replace PF_KCOMPACTD/PF_KSWAPD with kthread_func() Message-ID: References: <20260902131653.1338227-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260902131653.1338227-1-wangkefeng.wang@huawei.com> X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: hwqomyg8rbh4oe54hke1oi3xd7aognj7 X-Rspamd-Queue-Id: 69AFD18000C X-HE-Tag: 1788363107-812148 X-HE-Meta: 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 j20IuUeV F0tnO0CsMf4/1VorphI1aZIAdNhrW6IKavhVbaHalpsE4LpmruSxTfREFWYHHhBRLHkaO5dkFD55L7Rfa6txI/fddl29QplzDxaMUdQe5pMeSBoVHGMVVhMXDswSMRGkHyem2WTBxHC7NlKHD6f9XYw93nnTXv9UQRO6gIDHkwh/xtJYNBMKJKvjjRqkXx0wsGzjiec/4OQqnsyVD6H5HKOOf5pS4usE6ObC+zw+PjxIoeMnLPPDjCPdXPl7Nw83XHVd5CHrNc2be3DnIR5/0GdlA35vrpykV9ZtgDz+opFtqKhghYaRDn9dQSXJld9QF364u Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Sep 02, 2026 at 09:16:49PM +0800, Kefeng Wang wrote: > The task_struct->flags field is a limited 32-bit resource. Two flag bits, > PF_KCOMPACTD and PF_KSWAPD, are used to identify whether a kernel thread > is kcompactd or kswapd. Converting these to use kthread_func() frees up > two valuable flag bits for future use. I wouldn't call it a limited resource. We can have more fields in task_struct but I like the cleanups. > > Kefeng Wang (4): > xfs: remove dead kswapd flag inheritance from btree split worker > iomap: simplify writepages reclaim guard > mm: replace PF_KSWAPD flag with kthread_func() check > mm: replace PF_KCOMPACTD flag with kthread_func() check > > fs/iomap/buffered-io.c | 3 +-- > fs/xfs/libxfs/xfs_btree.c | 18 +----------------- > fs/xfs/xfs_platform.h | 4 ---- > include/linux/compaction.h | 11 ++++++----- > include/linux/sched.h | 4 ++-- > include/linux/swap.h | 7 +------ > mm/compaction.c | 9 ++++++--- > mm/vmscan.c | 10 ++++++++-- > tools/sched_ext/include/scx/common.bpf.h | 2 -- > 9 files changed, 25 insertions(+), 43 deletions(-) > > -- > 2.55.0 >