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b=0vWdZQZbYxNhpejmITKVe/DBQt4Jetkt6LpIKRdMA7af/7GIYi3igR6VNlHLc4RLx QNSAZ9Cb4VXzQonlKiMkFGr63gY2ITaCvdCnn71Qd2g6HeF3VgGTsVJHKfuv1RDuJE YgnTESkgX8U/sOoKL/NmcBu7KCA0dWsIsMdz4LFw= Date: Wed, 6 Aug 2025 15:31:46 -0700 From: Andrew Morton To: Chris Li Cc: Kemeng Shi , Kairui Song , Nhat Pham , Baoquan He , Barry Song , "Huang, Ying" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/swapfile.c: introduce function alloc_swap_scan_list() Message-Id: <20250806153146.ee1ee22dc8f6381ff5a6d882@linux-foundation.org> In-Reply-To: <20250806-swap-scan-list-v1-1-a5fe2d9340a2@kernel.org> References: <20250806-swap-scan-list-v1-1-a5fe2d9340a2@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 20740180009 X-Stat-Signature: o51kwd54qjezr54zid5ugpf8ds8ic1xd X-Rspam-User: X-HE-Tag: 1754519507-191936 X-HE-Meta: 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 5UJR8vVN iYAf+Z7JQY571AApKw4VnSY9wtBMDqEf4DVXAO3hiCTEMwbGhnJLxHvQRj6A8+Ml/w5cXlMyvcdwAlGljY+x4ZzVFWonVP59u6V+adirt75Pnd/z5YOaUuu2FIG6eWPHTldYXTG65jV/MpC/Es58VvWusO8sIPIsvVe/VZr2ZLFm2XqGOCaNJ/xqek+2wXcJPME7WlEyCAxg/sh94nyMw13qmuoTatZn9LynMMEJPTVLAAwbvpFJXXzm3rODwbvJX37CQ2ho/mdR/KrrkIO/10CPCf2CI/tQfxMGhNcrkvWi4SP+Qx9YFw8Np7NynU73MmfKa X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 06 Aug 2025 10:34:45 -0700 Chris Li wrote: > This the alloc_swap_scan_list() will scan the whole list or the first > cluster. > > This reduces the repeat patterns of isolating a cluster then scanning > that cluster. As a result, cluster_alloc_swap_entry() is shorter and shallower. > > No functional change. > ... > > --- > mm/swapfile.c | 86 ++++++++++++++++++++++++++++++++--------------------------- > 1 file changed, 47 insertions(+), 39 deletions(-) A nice little patch. > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 4a0cf4fb348d..fcb1e57d8108 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -820,6 +820,29 @@ static unsigned int alloc_swap_scan_cluster(struct swap_info_struct *si, > return found; > } > > +static unsigned int alloc_swap_scan_list(struct swap_info_struct *si, > + struct list_head *list, > + unsigned int order, > + unsigned char usage, > + bool scan_all) > +{ > + int found = SWAP_ENTRY_INVALID; but this function returns an unsigned int > + > + do { > + struct swap_cluster_info *ci = isolate_lock_cluster(si, list); > + unsigned long offset; > + > + if (!ci) > + break; > + offset = cluster_offset(si, ci); > + found = alloc_swap_scan_cluster(si, ci, offset, order, usage); so does that one > + if (found) > + return found; `break' here. To avoid multiple return points and for consistency. > + } while (scan_all); > + > + return found; > +} > + > static void swap_reclaim_full_clusters(struct swap_info_struct *si, bool force) > { > long to_scan = 1;