Date: Fri, 11 Oct 2019 14:57:47 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r353438 - head/sys/amd64/amd64 Message-ID: <201910111457.x9BEvlxh021080@repo.freebsd.org>
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Author: mjg Date: Fri Oct 11 14:57:47 2019 New Revision: 353438 URL: https://svnweb.freebsd.org/changeset/base/353438 Log: amd64 pmap: handle fictitious mappigns with addresses beyond pv_table There are provisions to do it already with pv_dummy, but new locking code did not account for it. Previous one did not have the problem because it hashed the address into the lock array. While here annotate common vars with __read_mostly and __exclusive_cache_line. Reported by: Thomas Laus Tesetd by: jkim, Thomas Laus Fixes: r353149 ("amd64 pmap: implement per-superpage locks") Sponsored by: The FreeBSD Foundation Modified: head/sys/amd64/amd64/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Fri Oct 11 14:17:31 2019 (r353437) +++ head/sys/amd64/amd64/pmap.c Fri Oct 11 14:57:47 2019 (r353438) @@ -325,8 +325,14 @@ pmap_pku_mask_bit(pmap_t pmap) #if VM_NRESERVLEVEL > 0 #define pa_to_pmdp(pa) (&pv_table[pa_index(pa)]) #define pa_to_pvh(pa) (&(pa_to_pmdp(pa)->pv_page)) -#define PHYS_TO_PV_LIST_LOCK(pa) \ - (&(pa_to_pmdp(pa)->pv_lock)) +#define PHYS_TO_PV_LIST_LOCK(pa) ({ \ + struct rwlock *_lock; \ + if (__predict_false((pa) > pmap_last_pa)) \ + _lock = &pv_dummy_large.pv_lock; \ + else \ + _lock = &(pa_to_pmdp(pa)->pv_lock); \ + _lock; \ +}) #else #define pa_to_pvh(pa) (&pv_table[pa_index(pa)]) @@ -422,13 +428,16 @@ struct pmap_large_md_page { struct md_page pv_page; u_long pv_invl_gen; }; -static struct pmap_large_md_page *pv_table; +__exclusive_cache_line static struct pmap_large_md_page pv_dummy_large; +#define pv_dummy pv_dummy_large.pv_page +__read_mostly static struct pmap_large_md_page *pv_table; +__read_mostly vm_paddr_t pmap_last_pa; #else static struct rwlock __exclusive_cache_line pv_list_locks[NPV_LIST_LOCKS]; static u_long pv_invl_gen[NPV_LIST_LOCKS]; static struct md_page *pv_table; -#endif static struct md_page pv_dummy; +#endif /* * All those kernel PT submaps that BSD is so fond of @@ -1851,7 +1860,8 @@ pmap_init_pv_table(void) /* * Calculate the size of the array. */ - pv_npg = howmany(vm_phys_segs[vm_phys_nsegs - 1].end, NBPDR); + pmap_last_pa = vm_phys_segs[vm_phys_nsegs - 1].end; + pv_npg = howmany(pmap_last_pa, NBPDR); s = (vm_size_t)pv_npg * sizeof(struct pmap_large_md_page); s = round_page(s); pv_table = (struct pmap_large_md_page *)kva_alloc(s); @@ -1894,7 +1904,12 @@ pmap_init_pv_table(void) pvd++; } } - TAILQ_INIT(&pv_dummy.pv_list); + pvd = &pv_dummy_large; + rw_init_flags(&pvd->pv_lock, "pmap pv list dummy", RW_NEW); + TAILQ_INIT(&pvd->pv_page.pv_list); + pvd->pv_page.pv_gen = 0; + pvd->pv_page.pat_mode = 0; + pvd->pv_invl_gen = 0; } #else static void
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