From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A54F01459EA; Thu, 14 Aug 2025 08:44:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755161047; cv=none; b=eIymfKwifjgSPW0YnL9NsE3DeyhfAaOxtrIXoubxHF2gtJJuEUFf9INq3+B1l9vFNcTyGFFkpDGQ+wBqg/YZ/pG4FVczAHgfkFznQ9IaCYGCQHM+OGSo8J2+XvO+muvb+Z3T07dKbZju6EFtadpJG3/cKTtgG8MfvK75IURteMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755161047; c=relaxed/simple; bh=CTmqLMuj0bCvkwKZAg1Un//8JJ/uJlUZHANgFIqPtcA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qeF/Q1kRSCnDuVF0OhfJ4WeG0uCTsOJXzehPnv//cZgQrWnppRIcAceU3D+tuVoiHckSfaWiQhBWBu4SUibJ40v2Go0LDJTqD3vMzviBKK88nRuyhDhYfE+sZ5fyR1gqMf7Ub+eh1icUVpkOH9oXwLzD3QOEz8DhmoJUtKjeaDE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nbIckPkp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nbIckPkp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 599B6C4CEEF; Thu, 14 Aug 2025 08:43:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755161047; bh=CTmqLMuj0bCvkwKZAg1Un//8JJ/uJlUZHANgFIqPtcA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nbIckPkpIEKyJ2nMayYZEQWySgIgwvq+Q87fMBsC5439jXwx7UjxtP6/3aRizI0iv ijsnrrrpc8/3O6G/xs9aYaXyUBJeY0IX4fqyj3/x/rGOzs3QvqOtEfqO4IsrCj1EJJ vVTmwcSsXtJ+0YCx16H+VWsKJOqsPoCy1fgAXOLlGkTP8ir2BQUm7OaO8V1W2MBlEh imVNM6O/c1ae9lGeBjLpZoDfgKf1bT+2dj2T7y2GbzlYFwT1eLdqkINwalGzjVIgUn KmVdVPjlyrTerI/WOq7DBLaaWbpmX/v+w8GbjVLyRf5VAICnpi3ce09BCy/VxWeJ9r 2nFsXdboCSbeg== Date: Thu, 14 Aug 2025 11:43:42 +0300 From: Mike Rapoport To: Lorenzo Stoakes Cc: Andrew Morton , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , "David S . Miller" , Andreas Larsson , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Alexander Viro , Christian Brauner , Jan Kara , Kees Cook , David Hildenbrand , Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Xu Xin , Chengming Zhou , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , David Rientjes , Shakeel Butt , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Masami Hiramatsu , Oleg Nesterov , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Jason Gunthorpe , John Hubbard , Peter Xu , Jann Horn , Pedro Falcato , Matthew Wilcox , Mateusz Guzik , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH 10/10] mm: replace mm->flags with bitmap entirely and set to 64 bits Message-ID: References: Precedence: bulk X-Mailing-List: sparclinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Aug 12, 2025 at 04:44:19PM +0100, Lorenzo Stoakes wrote: > Now we have updated all users of mm->flags to use the bitmap accessors, > repalce it with the bitmap version entirely. > > We are then able to move to having 64 bits of mm->flags on both 32-bit and > 64-bit architectures. > > We also update the VMA userland tests to ensure that everything remains > functional there. > > No functional changes intended, other than there now being 64 bits of > available mm_struct flags. > > Signed-off-by: Lorenzo Stoakes Reviewed-by: Mike Rapoport (Microsoft) > --- > include/linux/mm.h | 12 ++++++------ > include/linux/mm_types.h | 14 +++++--------- > include/linux/sched/coredump.h | 2 +- > tools/testing/vma/vma_internal.h | 19 +++++++++++++++++-- > 4 files changed, 29 insertions(+), 18 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 34311ebe62cc..b61e2d4858cf 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -724,32 +724,32 @@ static inline void assert_fault_locked(struct vm_fault *vmf) > > static inline bool mm_flags_test(int flag, const struct mm_struct *mm) > { > - return test_bit(flag, ACCESS_PRIVATE(&mm->_flags, __mm_flags)); > + return test_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); > } > > static inline bool mm_flags_test_and_set(int flag, struct mm_struct *mm) > { > - return test_and_set_bit(flag, ACCESS_PRIVATE(&mm->_flags, __mm_flags)); > + return test_and_set_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); > } > > static inline bool mm_flags_test_and_clear(int flag, struct mm_struct *mm) > { > - return test_and_clear_bit(flag, ACCESS_PRIVATE(&mm->_flags, __mm_flags)); > + return test_and_clear_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); > } > > static inline void mm_flags_set(int flag, struct mm_struct *mm) > { > - set_bit(flag, ACCESS_PRIVATE(&mm->_flags, __mm_flags)); > + set_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); > } > > static inline void mm_flags_clear(int flag, struct mm_struct *mm) > { > - clear_bit(flag, ACCESS_PRIVATE(&mm->_flags, __mm_flags)); > + clear_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); > } > > static inline void mm_flags_clear_all(struct mm_struct *mm) > { > - bitmap_zero(ACCESS_PRIVATE(&mm->_flags, __mm_flags), NUM_MM_FLAG_BITS); > + bitmap_zero(ACCESS_PRIVATE(&mm->flags, __mm_flags), NUM_MM_FLAG_BITS); > } > > extern const struct vm_operations_struct vma_dummy_vm_ops; > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 25577ab39094..47d2e4598acd 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -932,7 +932,7 @@ struct mm_cid { > * Opaque type representing current mm_struct flag state. Must be accessed via > * mm_flags_xxx() helper functions. > */ > -#define NUM_MM_FLAG_BITS BITS_PER_LONG > +#define NUM_MM_FLAG_BITS (64) > typedef struct { > __private DECLARE_BITMAP(__mm_flags, NUM_MM_FLAG_BITS); > } mm_flags_t; > @@ -1119,11 +1119,7 @@ struct mm_struct { > /* Architecture-specific MM context */ > mm_context_t context; > > - /* Temporary union while we convert users to mm_flags_t. */ > - union { > - unsigned long flags; /* Must use atomic bitops to access */ > - mm_flags_t _flags; /* Must use mm_flags_* helpers to access */ > - }; > + mm_flags_t flags; /* Must use mm_flags_* hlpers to access */ > > #ifdef CONFIG_AIO > spinlock_t ioctx_lock; > @@ -1236,7 +1232,7 @@ struct mm_struct { > /* Read the first system word of mm flags, non-atomically. */ > static inline unsigned long __mm_flags_get_word(struct mm_struct *mm) > { > - unsigned long *bitmap = ACCESS_PRIVATE(&mm->_flags, __mm_flags); > + unsigned long *bitmap = ACCESS_PRIVATE(&mm->flags, __mm_flags); > > return bitmap_read(bitmap, 0, BITS_PER_LONG); > } > @@ -1245,7 +1241,7 @@ static inline unsigned long __mm_flags_get_word(struct mm_struct *mm) > static inline void __mm_flags_set_word(struct mm_struct *mm, > unsigned long value) > { > - unsigned long *bitmap = ACCESS_PRIVATE(&mm->_flags, __mm_flags); > + unsigned long *bitmap = ACCESS_PRIVATE(&mm->flags, __mm_flags); > > bitmap_copy(bitmap, &value, BITS_PER_LONG); > } > @@ -1253,7 +1249,7 @@ static inline void __mm_flags_set_word(struct mm_struct *mm, > /* Obtain a read-only view of the bitmap. */ > static inline const unsigned long *__mm_flags_get_bitmap(const struct mm_struct *mm) > { > - return (const unsigned long *)ACCESS_PRIVATE(&mm->_flags, __mm_flags); > + return (const unsigned long *)ACCESS_PRIVATE(&mm->flags, __mm_flags); > } > > #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \ > diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h > index 19ecfcceb27a..079ae5a97480 100644 > --- a/include/linux/sched/coredump.h > +++ b/include/linux/sched/coredump.h > @@ -20,7 +20,7 @@ static inline unsigned long __mm_flags_get_dumpable(struct mm_struct *mm) > > static inline void __mm_flags_set_mask_dumpable(struct mm_struct *mm, int value) > { > - unsigned long *bitmap = ACCESS_PRIVATE(&mm->_flags, __mm_flags); > + unsigned long *bitmap = ACCESS_PRIVATE(&mm->flags, __mm_flags); > > set_mask_bits(bitmap, MMF_DUMPABLE_MASK, value); > } > diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h > index cb1c2a8afe26..f13354bf0a1e 100644 > --- a/tools/testing/vma/vma_internal.h > +++ b/tools/testing/vma/vma_internal.h > @@ -249,6 +249,14 @@ struct mutex {}; > #define DEFINE_MUTEX(mutexname) \ > struct mutex mutexname = {} > > +#define DECLARE_BITMAP(name, bits) \ > + unsigned long name[BITS_TO_LONGS(bits)] > + > +#define NUM_MM_FLAG_BITS (64) > +typedef struct { > + __private DECLARE_BITMAP(__mm_flags, NUM_MM_FLAG_BITS); > +} mm_flags_t; > + > struct mm_struct { > struct maple_tree mm_mt; > int map_count; /* number of VMAs */ > @@ -260,7 +268,7 @@ struct mm_struct { > > unsigned long def_flags; > > - unsigned long flags; /* Must use atomic bitops to access */ > + mm_flags_t flags; /* Must use mm_flags_* helpers to access */ > }; > > struct vm_area_struct; > @@ -1333,6 +1341,13 @@ static inline void userfaultfd_unmap_complete(struct mm_struct *mm, > { > } > > +# define ACCESS_PRIVATE(p, member) ((p)->member) > + > +static inline bool mm_flags_test(int flag, const struct mm_struct *mm) > +{ > + return test_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); > +} > + > /* > * Denies creating a writable executable mapping or gaining executable permissions. > * > @@ -1363,7 +1378,7 @@ static inline void userfaultfd_unmap_complete(struct mm_struct *mm, > static inline bool map_deny_write_exec(unsigned long old, unsigned long new) > { > /* If MDWE is disabled, we have nothing to deny. */ > - if (!test_bit(MMF_HAS_MDWE, ¤t->mm->flags)) > + if (mm_flags_test(MMF_HAS_MDWE, current->mm)) > return false; > > /* If the new VMA is not executable, we have nothing to deny. */ > -- > 2.50.1 > -- Sincerely yours, Mike.