From: "Petr Tesařík" <petr@tesarici.cz>
To: Suren Baghdasaryan <surenb@google.com>
Cc: Neil Brown <neilb@suse.de>,
akpm@linux-foundation.org, kent.overstreet@linux.dev,
mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org,
roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net,
willy@infradead.org, liam.howlett@oracle.com, corbet@lwn.net,
void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com,
ldufour@linux.ibm.com, catalin.marinas@arm.com, will@kernel.org,
arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com,
dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com,
david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org,
masahiroy@kernel.org, nathan@kernel.org, dennis@kernel.org,
tj@kernel.org, muchun.song@linux.dev, rppt@kernel.org,
paulmck@kernel.org, pasha.tatashin@soleen.com,
yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.com,
hughd@google.com, andreyknvl@gmail.com, keescook@chromium.org,
ndesaulniers@google.com, vvvvvv@google.com,
gregkh@linuxfoundation.org, ebiggers@google.com,
ytcoode@gmail.com, vincent.guittot@linaro.org,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, bristot@redhat.com, vschneid@redhat.com,
cl@linux.com, penberg@kernel.org, iamjoonsoo.kim@lge.com,
42.hyeyoo@gmail.com, glider@google.com, elver@google.com,
dvyukov@google.com, shakeelb@google.com,
songmuchun@bytedance.com, jbaron@akamai.com, rientjes@google.com,
minchan@google.com, kaleshsingh@google.com,
kernel-team@android.com, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-modules@vger.kernel.org,
kasan-dev@googlegroups.com, cgroups@vger.kernel.org
Subject: Re: [PATCH v2 06/39] mm: enumerate all gfp flags
Date: Sat, 28 Oct 2023 19:21:47 +0200 [thread overview]
Message-ID: <20231028192147.2a755c46@meshulam.tesarici.cz> (raw)
In-Reply-To: <CAJuCfpHS1JTRU69zFDAJjmMYR3K5TAS9+AsA3oYLs2LCs5aTBw@mail.gmail.com>
On Wed, 25 Oct 2023 08:28:32 -0700
Suren Baghdasaryan <surenb@google.com> wrote:
> On Tue, Oct 24, 2023 at 10:47 PM Petr Tesařík <petr@tesarici.cz> wrote:
> >
> > On Tue, 24 Oct 2023 06:46:03 -0700
> > Suren Baghdasaryan <surenb@google.com> wrote:
> >
> > > Introduce GFP bits enumeration to let compiler track the number of used
> > > bits (which depends on the config options) instead of hardcoding them.
> > > That simplifies __GFP_BITS_SHIFT calculation.
> > > Suggested-by: Petr Tesařík <petr@tesarici.cz>
> > > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> > > ---
> > > include/linux/gfp_types.h | 90 +++++++++++++++++++++++++++------------
> > > 1 file changed, 62 insertions(+), 28 deletions(-)
> > >
> > > diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
> > > index 6583a58670c5..3fbe624763d9 100644
> > > --- a/include/linux/gfp_types.h
> > > +++ b/include/linux/gfp_types.h
> > > @@ -21,44 +21,78 @@ typedef unsigned int __bitwise gfp_t;
> > > * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
> > > */
> > >
> > > +enum {
> > > + ___GFP_DMA_BIT,
> > > + ___GFP_HIGHMEM_BIT,
> > > + ___GFP_DMA32_BIT,
> > > + ___GFP_MOVABLE_BIT,
> > > + ___GFP_RECLAIMABLE_BIT,
> > > + ___GFP_HIGH_BIT,
> > > + ___GFP_IO_BIT,
> > > + ___GFP_FS_BIT,
> > > + ___GFP_ZERO_BIT,
> > > + ___GFP_UNUSED_BIT, /* 0x200u unused */
> > > + ___GFP_DIRECT_RECLAIM_BIT,
> > > + ___GFP_KSWAPD_RECLAIM_BIT,
> > > + ___GFP_WRITE_BIT,
> > > + ___GFP_NOWARN_BIT,
> > > + ___GFP_RETRY_MAYFAIL_BIT,
> > > + ___GFP_NOFAIL_BIT,
> > > + ___GFP_NORETRY_BIT,
> > > + ___GFP_MEMALLOC_BIT,
> > > + ___GFP_COMP_BIT,
> > > + ___GFP_NOMEMALLOC_BIT,
> > > + ___GFP_HARDWALL_BIT,
> > > + ___GFP_THISNODE_BIT,
> > > + ___GFP_ACCOUNT_BIT,
> > > + ___GFP_ZEROTAGS_BIT,
> > > +#ifdef CONFIG_KASAN_HW_TAGS
> > > + ___GFP_SKIP_ZERO_BIT,
> > > + ___GFP_SKIP_KASAN_BIT,
> > > +#endif
> > > +#ifdef CONFIG_LOCKDEP
> > > + ___GFP_NOLOCKDEP_BIT,
> > > +#endif
> > > + ___GFP_LAST_BIT
> > > +};
> > > +
> > > /* Plain integer GFP bitmasks. Do not use this directly. */
> > > -#define ___GFP_DMA 0x01u
> > > -#define ___GFP_HIGHMEM 0x02u
> > > -#define ___GFP_DMA32 0x04u
> > > -#define ___GFP_MOVABLE 0x08u
> > > -#define ___GFP_RECLAIMABLE 0x10u
> > > -#define ___GFP_HIGH 0x20u
> > > -#define ___GFP_IO 0x40u
> > > -#define ___GFP_FS 0x80u
> > > -#define ___GFP_ZERO 0x100u
> > > +#define ___GFP_DMA BIT(___GFP_DMA_BIT)
> > > +#define ___GFP_HIGHMEM BIT(___GFP_HIGHMEM_BIT)
> > > +#define ___GFP_DMA32 BIT(___GFP_DMA32_BIT)
> > > +#define ___GFP_MOVABLE BIT(___GFP_MOVABLE_BIT)
> > > +#define ___GFP_RECLAIMABLE BIT(___GFP_RECLAIMABLE_BIT)
> > > +#define ___GFP_HIGH BIT(___GFP_HIGH_BIT)
> > > +#define ___GFP_IO BIT(___GFP_IO_BIT)
> > > +#define ___GFP_FS BIT(___GFP_FS_BIT)
> > > +#define ___GFP_ZERO BIT(___GFP_ZERO_BIT)
> > > /* 0x200u unused */
> >
> > This comment can be also removed here, because it is already stated
> > above with the definition of ___GFP_UNUSED_BIT.
>
> Ack.
>
> >
> > Then again, I think that the GFP bits have never been compacted after
> > Neil Brown removed __GFP_ATOMIC with commit 2973d8229b78 simply because
> > that would mean changing definitions of all subsequent GFP flags. FWIW
> > I am not aware of any code that would depend on the numeric value of
> > ___GFP_* macros, so this patch seems like a good opportunity to change
> > the numbering and get rid of this unused 0x200u altogether.
> >
> > @Neil: I have added you to the conversation in case you want to correct
> > my understanding of the unused bit.
>
> Hmm. I would prefer to do that in a separate patch even though it
> would be a one-line change. Seems safer to me in case something goes
> wrong and we have to bisect and revert it. If that sounds ok I'll post
> that in the next version.
You're right. If something does go wrong, it will be easier to fix if
the removal of the unused bit is in a commit of its own.
Petr T
next prev parent reply other threads:[~2023-10-28 17:21 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-24 13:45 [PATCH v2 00/39] Memory allocation profiling Suren Baghdasaryan
2023-10-24 13:45 ` [PATCH v2 01/39] lib/string_helpers: Add flags param to string_get_size() Suren Baghdasaryan
2023-10-24 13:45 ` [PATCH v2 02/39] scripts/kallysms: Always include __start and __stop symbols Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 03/39] fs: Convert alloc_inode_sb() to a macro Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 04/39] nodemask: Split out include/linux/nodemask_types.h Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 05/39] prandom: Remove unused include Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 06/39] mm: enumerate all gfp flags Suren Baghdasaryan
2023-10-25 5:46 ` Petr Tesařík
2023-10-25 15:28 ` Suren Baghdasaryan
2023-10-28 17:21 ` Petr Tesařík [this message]
2023-10-24 13:46 ` [PATCH v2 07/39] mm: introduce slabobj_ext to support slab object extensions Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 08/39] mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 09/39] mm/slab: introduce SLAB_NO_OBJ_EXT to avoid obj_ext creation Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 10/39] mm: prevent slabobj_ext allocations for slabobj_ext and kmem_cache objects Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 11/39] slab: objext: introduce objext_flags as extension to page_memcg_data_flags Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 12/39] lib: code tagging framework Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 13/39] lib: code tagging module support Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 14/39] lib: prevent module unloading if memory is not freed Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 15/39] lib: add allocation tagging support for memory allocation profiling Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 16/39] lib: introduce support for page allocation tagging Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 17/39] change alloc_pages name in dma_map_ops to avoid name conflicts Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 18/39] change alloc_pages name in ivpu_bo_ops to avoid conflicts Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 19/39] mm: enable page allocation tagging Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 20/39] mm: create new codetag references during page splitting Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 21/39] mm/page_ext: enable early_page_ext when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 22/39] lib: add codetag reference into slabobj_ext Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 23/39] mm/slab: add allocation accounting into slab allocation and free paths Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 24/39] mm/slab: enable slab allocation tagging for kmalloc and friends Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 25/39] mm/slub: Mark slab_free_freelist_hook() __always_inline Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 26/39] mempool: Hook up to memory allocation profiling Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 27/39] xfs: Memory allocation profiling fixups Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 28/39] timekeeping: Fix a circular include dependency Suren Baghdasaryan
2023-10-25 17:33 ` Thomas Gleixner
2023-10-26 18:33 ` Suren Baghdasaryan
2023-10-26 23:05 ` Thomas Gleixner
2023-10-26 23:54 ` Kent Overstreet
2023-10-27 6:35 ` Arnd Bergmann
2023-10-27 15:28 ` Nick Desaulniers
2023-10-24 13:46 ` [PATCH v2 29/39] mm: percpu: Introduce pcpuobj_ext Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 30/39] mm: percpu: Add codetag reference into pcpuobj_ext Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 31/39] mm: percpu: enable per-cpu allocation tagging Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 32/39] arm64: Fix circular header dependency Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 33/39] mm: vmalloc: Enable memory allocation profiling Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 34/39] rhashtable: Plumb through alloc tag Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 35/39] lib: add memory allocations report in show_mem() Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 36/39] codetag: debug: skip objext checking when it's for objext itself Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 37/39] codetag: debug: mark codetags for reserved pages as empty Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 38/39] codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations Suren Baghdasaryan
2023-10-24 13:46 ` [PATCH v2 39/39] MAINTAINERS: Add entries for code tagging and memory allocation profiling Suren Baghdasaryan
2023-10-24 18:29 ` [PATCH v2 00/39] Memory " Roman Gushchin
2023-10-24 18:38 ` Suren Baghdasaryan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231028192147.2a755c46@meshulam.tesarici.cz \
--to=petr@tesarici.cz \
--cc=42.hyeyoo@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=andreyknvl@gmail.com \
--cc=arnd@arndb.de \
--cc=axboe@kernel.dk \
--cc=bristot@redhat.com \
--cc=bsegall@google.com \
--cc=catalin.marinas@arm.com \
--cc=cgroups@vger.kernel.org \
--cc=cl@linux.com \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=dave@stgolabs.net \
--cc=david@redhat.com \
--cc=dennis@kernel.org \
--cc=dhowells@redhat.com \
--cc=dietmar.eggemann@arm.com \
--cc=dvyukov@google.com \
--cc=ebiggers@google.com \
--cc=elver@google.com \
--cc=glider@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=iamjoonsoo.kim@lge.com \
--cc=iommu@lists.linux.dev \
--cc=jbaron@akamai.com \
--cc=juri.lelli@redhat.com \
--cc=kaleshsingh@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=keescook@chromium.org \
--cc=kent.overstreet@linux.dev \
--cc=kernel-team@android.com \
--cc=ldufour@linux.ibm.com \
--cc=liam.howlett@oracle.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-modules@vger.kernel.org \
--cc=masahiroy@kernel.org \
--cc=mcgrof@kernel.org \
--cc=mgorman@suse.de \
--cc=mhocko@suse.com \
--cc=minchan@google.com \
--cc=mingo@redhat.com \
--cc=muchun.song@linux.dev \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=neilb@suse.de \
--cc=pasha.tatashin@soleen.com \
--cc=paulmck@kernel.org \
--cc=penberg@kernel.org \
--cc=peterx@redhat.com \
--cc=peterz@infradead.org \
--cc=rientjes@google.com \
--cc=roman.gushchin@linux.dev \
--cc=rostedt@goodmis.org \
--cc=rppt@kernel.org \
--cc=shakeelb@google.com \
--cc=songmuchun@bytedance.com \
--cc=surenb@google.com \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
--cc=vbabka@suse.cz \
--cc=vincent.guittot@linaro.org \
--cc=void@manifault.com \
--cc=vschneid@redhat.com \
--cc=vvvvvv@google.com \
--cc=will@kernel.org \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
--cc=yosryahmed@google.com \
--cc=ytcoode@gmail.com \
--cc=yuzhao@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).