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Content-Language: en-US To: Zi Yan , David Hildenbrand , Johannes Weiner , linux-mm@kvack.org Cc: Andrew Morton , Oscar Salvador , Baolin Wang , "Kirill A . Shutemov" , Mel Gorman , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Richard Chang , linux-kernel@vger.kernel.org References: <20250523191258.339826-1-ziy@nvidia.com> <20250523191258.339826-2-ziy@nvidia.com> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJnyBr8BQka0IFQAAoJECJPp+fMgqZkqmMQ AIbGN95ptUMUvo6aAdhxaOCHXp1DfIBuIOK/zpx8ylY4pOwu3GRe4dQ8u4XS9gaZ96Gj4bC+ jwWcSmn+TjtKW3rH1dRKopvC07tSJIGGVyw7ieV/5cbFffA8NL0ILowzVg8w1ipnz1VTkWDr 2zcfslxJsJ6vhXw5/npcY0ldeC1E8f6UUoa4eyoskd70vO0wOAoGd02ZkJoox3F5ODM0kjHu Y97VLOa3GG66lh+ZEelVZEujHfKceCw9G3PMvEzyLFbXvSOigZQMdKzQ8D/OChwqig8wFBmV QCPS4yDdmZP3oeDHRjJ9jvMUKoYODiNKsl2F+xXwyRM2qoKRqFlhCn4usVd1+wmv9iLV8nPs 2Db1ZIa49fJet3Sk3PN4bV1rAPuWvtbuTBN39Q/6MgkLTYHb84HyFKw14Rqe5YorrBLbF3rl M51Dpf6Egu1yTJDHCTEwePWug4XI11FT8lK0LNnHNpbhTCYRjX73iWOnFraJNcURld1jL1nV r/LRD+/e2gNtSTPK0Qkon6HcOBZnxRoqtazTU6YQRmGlT0v+rukj/cn5sToYibWLn+RoV1CE Qj6tApOiHBkpEsCzHGu+iDQ1WT0Idtdynst738f/uCeCMkdRu4WMZjteQaqvARFwCy3P/jpK uvzMtves5HvZw33ZwOtMCgbpce00DaET4y/UzsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZ8gcVAUJFhTonwAKCRAiT6fnzIKmZLY8D/9uo3Ut9yi2YCuASWxr7QQZ lJCViArjymbxYB5NdOeC50/0gnhK4pgdHlE2MdwF6o34x7TPFGpjNFvycZqccSQPJ/gibwNA zx3q9vJT4Vw+YbiyS53iSBLXMweeVV1Jd9IjAoL+EqB0cbxoFXvnjkvP1foiiF5r73jCd4PR rD+GoX5BZ7AZmFYmuJYBm28STM2NA6LhT0X+2su16f/HtummENKcMwom0hNu3MBNPUOrujtW khQrWcJNAAsy4yMoJ2Lw51T/5X5Hc7jQ9da9fyqu+phqlVtn70qpPvgWy4HRhr25fCAEXZDp xG4RNmTm+pqorHOqhBkI7wA7P/nyPo7ZEc3L+ZkQ37u0nlOyrjbNUniPGxPxv1imVq8IyycG AN5FaFxtiELK22gvudghLJaDiRBhn8/AhXc642/Z/yIpizE2xG4KU4AXzb6C+o7LX/WmmsWP Ly6jamSg6tvrdo4/e87lUedEqCtrp2o1xpn5zongf6cQkaLZKQcBQnPmgHO5OG8+50u88D9I rywqgzTUhHFKKF6/9L/lYtrNcHU8Z6Y4Ju/MLUiNYkmtrGIMnkjKCiRqlRrZE/v5YFHbayRD dJKXobXTtCBYpLJM4ZYRpGZXne/FAtWNe4KbNJJqxMvrTOrnIatPj8NhBVI0RSJRsbilh6TE m6M14QORSWTLRg== In-Reply-To: <20250523191258.339826-2-ziy@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCPT_COUNT_TWELVE(0.00)[14]; FUZZY_BLOCKED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo,nvidia.com:email,suse.cz:mid,suse.cz:dkim]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:104:10:150:64:97:from,2a07:de40:b281:106:10:150:64:167:received]; DKIM_TRACE(0.00)[suse.cz:+] X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Queue-Id: 654AF21ECD X-Spam-Flag: NO X-Spam-Level: X-Spam-Score: -4.51 On 5/23/25 21:12, Zi Yan wrote: > No functional change is intended. > > 1. Add __NR_PAGEBLOCK_BITS for the number of pageblock flag bits and use > roundup_pow_of_two(__NR_PAGEBLOCK_BITS) as NR_PAGEBLOCK_BITS to take > right amount of bits for pageblock flags. > 2. Add {get,set,clear}_pfnblock_bit() to operate one a standalone bit, > like PB_migrate_skip. > 3. Make {get,set}_pfnblock_flags_mask() internal functions and use > {get,set}_pfnblock_migratetype() for pageblock migratetype operations. > 4. Move pageblock flags common code to get_pfnblock_bitmap_bitidx(). > 3. Use MIGRATETYPE_MASK to get the migratetype of a pageblock from its > flags. > 4. Use PB_migrate_end in the definition of MIGRATETYPE_MASK instead of > PB_migrate_bits. > 5. Add a comment on is_migrate_cma_folio() to prevent one from changing it > to use get_pageblock_migratetype() and causing issues. > > Signed-off-by: Zi Yan > +/** > + * __set_pfnblock_flags_mask - Set the requested group of flags for > + * a pageblock_nr_pages block of pages > * @page: The page within the block of interest > - * @flags: The flags to set > * @pfn: The target page frame number > + * @flags: The flags to set > * @mask: mask of bits that the caller is interested in > */ > -void set_pfnblock_flags_mask(struct page *page, unsigned long flags, > - unsigned long pfn, > - unsigned long mask) > +static void __set_pfnblock_flags_mask(struct page *page, unsigned long pfn, > + unsigned long flags, unsigned long mask) > { > - unsigned long *bitmap; > - unsigned long bitidx, word_bitidx; > + unsigned long *bitmap_word; > + unsigned long bitidx; > unsigned long word; > > - BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); > - BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits)); > - > - bitmap = get_pageblock_bitmap(page, pfn); > - bitidx = pfn_to_bitidx(page, pfn); > - word_bitidx = bitidx / BITS_PER_LONG; > - bitidx &= (BITS_PER_LONG-1); > - > - VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); > + get_pfnblock_bitmap_bitidx(page, pfn, &bitmap_word, &bitidx); > > mask <<= bitidx; > flags <<= bitidx; > > - word = READ_ONCE(bitmap[word_bitidx]); > + word = READ_ONCE(*bitmap_word); > do { > - } while (!try_cmpxchg(&bitmap[word_bitidx], &word, (word & ~mask) | flags)); > + } while (!try_cmpxchg(bitmap_word, &word, (word & ~mask) | flags)); > +} > + > +/** > + * set_pfnblock_bit - Set a standalone bit of a pageblock > + * @page: The page within the block of interest > + * @pfn: The target page frame number > + * @pb_bit: pageblock bit to set > + */ > +void set_pfnblock_bit(const struct page *page, unsigned long pfn, > + enum pageblock_bits pb_bit) > +{ > + unsigned long *bitmap_word; > + unsigned long bitidx; > + > + if (WARN_ON_ONCE(pb_bit <= PB_migrate_end || > + pb_bit >= __NR_PAGEBLOCK_BITS)) > + return; This check appears at 3 places, maybe worth wrapping it in a helper? > + > + get_pfnblock_bitmap_bitidx(page, pfn, &bitmap_word, &bitidx); > + > + __set_bit(bitidx + pb_bit, bitmap_word); I think it's wrong to use the __set_bit non-atomic variant because e.g. compaction's PB_migrate_skip (actually a misnomer at this point I think, e.g. PB_compact_skip would make more sense if you wanted to clean up things some more) can be modified with no lock. It's why __set_pfnblock_flags_mask() above uses try_cmpxchg() even though changes to migratetype are normally done under zone lock. > +} > + > +/** > + * clear_pfnblock_bit - Clear a standalone bit of a pageblock > + * @page: The page within the block of interest > + * @pfn: The target page frame number > + * @pb_bit: pageblock bit to clear > + */ > +void clear_pfnblock_bit(const struct page *page, unsigned long pfn, > + enum pageblock_bits pb_bit) > +{ > + unsigned long *bitmap_word; > + unsigned long bitidx; > + > + if (WARN_ON_ONCE(pb_bit <= PB_migrate_end || > + pb_bit >= __NR_PAGEBLOCK_BITS)) > + return; > + > + get_pfnblock_bitmap_bitidx(page, pfn, &bitmap_word, &bitidx); > + > + __clear_bit(bitidx + pb_bit, bitmap_word); Same here. > }