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Shutemov" , Mel Gorman , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Richard Chang , linux-kernel@vger.kernel.org References: <20250523191258.339826-1-ziy@nvidia.com> <20250523191258.339826-5-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: <20250523191258.339826-5-ziy@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Rspamd-Action: no action X-Spamd-Result: default: False [-3.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; 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)[]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; RCPT_COUNT_TWELVE(0.00)[14]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; 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)[suse.cz:dkim,suse.cz:mid]; DKIM_TRACE(0.00)[suse.cz:+] X-Rspamd-Queue-Id: 4C1AF1F835 X-Spam-Flag: NO X-Spam-Score: -3.51 X-Spam-Level: On 5/23/25 21:12, Zi Yan wrote: > Since migratetype is no longer overwritten during pageblock isolation, > moving a pageblock out of MIGRATE_ISOLATE no longer needs a new > migratetype. > > Add pageblock_isolate_and_move_free_pages() and > pageblock_unisolate_and_move_free_pages() to be explicit about the page > isolation operations. Both share the common code in > __move_freepages_block_isolate(), which is renamed from > move_freepages_block_isolate(). > > Add toggle_pageblock_isolate() to flip pageblock isolation bit in > __move_freepages_block_isolate(). > > Make set_pageblock_migratetype() only accept non MIGRATE_ISOLATE types, > so that one should use set_pageblock_isolate() to isolate pageblocks. > As a result, move pageblock migratetype code out of > __move_freepages_block(). > > Signed-off-by: Zi Yan > --- > include/linux/page-isolation.h | 5 +- > mm/page_alloc.c | 97 ++++++++++++++++++++++++++++------ > mm/page_isolation.c | 21 ++++---- > 3 files changed, 92 insertions(+), 31 deletions(-) > > diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h > index 14c6a5f691c2..7241a6719618 100644 > --- a/include/linux/page-isolation.h > +++ b/include/linux/page-isolation.h > @@ -44,10 +44,9 @@ static inline void set_pageblock_isolate(struct page *page) > void __meminit init_pageblock_migratetype(struct page *page, > enum migratetype migratetype, > bool isolate); > -void set_pageblock_migratetype(struct page *page, enum migratetype migratetype); > > -bool move_freepages_block_isolate(struct zone *zone, struct page *page, > - int migratetype); > +bool pageblock_isolate_and_move_free_pages(struct zone *zone, struct page *page); > +bool pageblock_unisolate_and_move_free_pages(struct zone *zone, struct page *page); > > int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, > int migratetype, int flags); > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 8fcbd7fa13c2..44a08b1a9de4 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -524,13 +524,36 @@ void clear_pfnblock_bit(const struct page *page, unsigned long pfn, > __clear_bit(bitidx + pb_bit, bitmap_word); > } > > +#ifdef CONFIG_MEMORY_ISOLATION > +/** > + * toggle_pfnblock_bit - Toggle 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 toggle > + */ > +static void toggle_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); > + > + __change_bit(bitidx + pb_bit, bitmap_word); Again the non-atomic variant, but actually below I suggest we drop this. > +} > +#endif > + > /** > * set_pageblock_migratetype - Set the migratetype of a pageblock > * @page: The page within the block of interest > * @migratetype: migratetype to set > */ > -__always_inline void set_pageblock_migratetype(struct page *page, > - enum migratetype migratetype) > +static void set_pageblock_migratetype(struct page *page, > + enum migratetype migratetype) > { > unsigned long mask = MIGRATETYPE_MASK; > > @@ -540,11 +563,15 @@ __always_inline void set_pageblock_migratetype(struct page *page, > > #ifdef CONFIG_MEMORY_ISOLATION > if (migratetype == MIGRATE_ISOLATE) { > - set_pfnblock_bit(page, page_to_pfn(page), PB_migrate_isolate); > + VM_WARN_ONCE(1, > + "Use set_pageblock_isolate() for pageblock isolation"); > return; > } > /* change mask to clear PB_migrate_isolate if it is set */ > mask = MIGRATETYPE_AND_ISO_MASK; > + VM_WARN_ONCE(get_pfnblock_bit(page, page_to_pfn(page), > + PB_migrate_isolate), > + "Use clear_pageblock_isolate() to unisolate pageblock"); > #endif We might be too paranoid with the warnings given these are all local functions to this file so risk of misuse should be low. Maybe we could remove later... > __set_pfnblock_flags_mask(page, page_to_pfn(page), > (unsigned long)migratetype, mask); > @@ -1931,8 +1958,8 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone, > #endif > > /* > - * Change the type of a block and move all its free pages to that > - * type's freelist. > + * Move all free pages of a block to new type's freelist. Caller needs to > + * change the block type. > */ > static int __move_freepages_block(struct zone *zone, unsigned long start_pfn, > int old_mt, int new_mt) > @@ -1964,8 +1991,6 @@ static int __move_freepages_block(struct zone *zone, unsigned long start_pfn, > pages_moved += 1 << order; > } > > - set_pageblock_migratetype(pfn_to_page(start_pfn), new_mt); > - > return pages_moved; > } > > @@ -2023,11 +2048,16 @@ static int move_freepages_block(struct zone *zone, struct page *page, > int old_mt, int new_mt) > { > unsigned long start_pfn; > + int res; > > if (!prep_move_freepages_block(zone, page, &start_pfn, NULL, NULL)) > return -1; > > - return __move_freepages_block(zone, start_pfn, old_mt, new_mt); > + res = __move_freepages_block(zone, start_pfn, old_mt, new_mt); > + set_pageblock_migratetype(pfn_to_page(start_pfn), new_mt); > + > + return res; > + > } > > #ifdef CONFIG_MEMORY_ISOLATION > @@ -2055,11 +2085,16 @@ static unsigned long find_large_buddy(unsigned long start_pfn) > return start_pfn; > } > > +static inline void toggle_pageblock_isolate(struct page *page) > +{ > + toggle_pfnblock_bit(page, page_to_pfn(page), PB_migrate_isolate); > +} I'm wary about the togle action, as we should always know what action we want to do anyway. So we could just add a "bool isolate" parameter and call set or clear explicitly? Allows for some hypothetical DEBUG_VM checks too (pageblock is not already in the state we want it to be).