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Wysocki" , Robin Murphy , linux-mm@kvack.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 0D51D40006 X-Stat-Signature: z98ax1w95aiey15ddarqhx1dt8e6rp9m X-HE-Tag: 1684433603-631329 X-HE-Meta: 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 GsWBCigx 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 18 May 2023 at 19:56, Linus Torvalds wrote: > > On Thu, May 18, 2023 at 10:34=E2=80=AFAM Catalin Marinas > wrote: > > > > That's the fourth version of the series reducing the kmalloc() minimum > > alignment on arm64 to 8 (from 128). For the series: Tested-by: Ard Biesheuvel # tx2 and I am seeing lots of smaller allocations, all of which would have otherwise taken up 128 or 256 bytes: kmalloc-192 6426 6426 192 42 2 : tunables 0 0 0 : slabdata 153 153 0 kmalloc-128 9472 9472 128 64 2 : tunables 0 0 0 : slabdata 148 148 0 kmalloc-96 15666 15666 96 42 1 : tunables 0 0 0 : slabdata 373 373 0 kmalloc-64 21952 21952 64 64 1 : tunables 0 0 0 : slabdata 343 343 0 kmalloc-32 23424 23424 32 128 1 : tunables 0 0 0 : slabdata 183 183 0 kmalloc-16 41216 41216 16 256 1 : tunables 0 0 0 : slabdata 161 161 0 kmalloc-8 77846 80384 8 512 1 : tunables 0 0 0 : slabdata 157 157 0 The box is fully DMA coherent, of course, so this doesn't really tell us whether the swiotlb DMA bouncing stuff works or not. > > Lovely. On my M2 Macbook air, I right now have about 24MB in the > kmalloc-128 bucket, and most of it is presumably just 16 byte > allocations (judging by my x86-64 slabinfo). > > I guess it doesn't really matter when I have 16GB in the machine, but > this has annoyed me for a while. > Yeah but surely the overhead in terms of D-cache footprint is a factor here= too? > It feels like this is ready for 6.5, no? > Yes, please...