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charset="UTF-8" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667938467; a=rsa-sha256; cv=none; b=Dm8bwNN/jJFkhZzebNmV0zMvnsFDE1D7z8xrr/ZY0P06LQpt+vyVtjc0Q2rh0a368dLMS6 UlKgWyveEz3X+hiSSrcQSpXLn5NRJjmmJjR4Y9940leyklNW0oMqbkv7pv1lTvczYXGm1P JAdcUZUehEwdgNOES42aHYs9fS8xbxU= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=YRBngXpR; spf=pass (imf29.hostedemail.com: domain of yosryahmed@google.com designates 209.85.166.42 as permitted sender) smtp.mailfrom=yosryahmed@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667938467; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=cLWjdLjmwzQQilsftQhHY/hR2bx8uTMFOs2rhKH1YPE=; b=dT8iF9oSus86BsHd+KyPowvD6vG/Yl5mjMPEUqacP3PfnsdUnrKh4oZ2DiuxQTxzM9gNg2 xChKuoC0yr0XGplNDI8KWG0I81FELCKXgofZ+Za8mCcm2X+pWX+JH0UB5Dn8dMH7S3XmTt +MDqUhjzSRvb2wtDAXheyOxYis5JRPs= X-Stat-Signature: soqcfzmse3bjzgybnkyd9xw4x6srgi7w X-Rspam-User: Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=YRBngXpR; spf=pass (imf29.hostedemail.com: domain of yosryahmed@google.com designates 209.85.166.42 as permitted sender) smtp.mailfrom=yosryahmed@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Queue-Id: 4CF0D12000C X-Rspamd-Server: rspam09 X-HE-Tag: 1667938467-350650 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 Tue, Nov 8, 2022 at 10:47 AM Roman Gushchin wrote: > > On Tue, Nov 08, 2022 at 04:55:29PM +0100, Vlastimil Babka wrote: > > Hi, > > > > as we all know, we currently have three slab allocators. As we discussed at > > LPC [1], it is my hope that one of these allocators has a future, and two of > > them do not. > > > > The unsurprising reasons include code maintenance burden, other features > > compatible with only a subset of allocators (or more effort spent on the > > features), blocking API improvements (more on that below), and my inability > > to pronounce SLAB and SLUB in a properly distinguishable way, without > > resorting to spelling out the letters. > > > > I think (but may be proven wrong) that SLOB is the easier target of the two > > to be removed, so I'd like to focus on it first. > > Great! > > SLOB is not supported by the kernel memory accounting code, so if we'll > deprecate SLOB, we can remove all those annoying ifndefs. > > But I wonder if we can deprecate SLAB too? Or at least use the moment to > ask every non-SLUB user on why they can't/don't want to use SLUB. > Are there any known advantages of SLAB over SLUB? We use SLAB at Google, but I am not the right person to answer the question of why we can't/don't use SLUB. Adding Greg here who recently looked into this and might have answers. I see David is already tagged, he might have a good answer as well. > > Also, for memory-constrained users we might want to add some guide on how > to configure SLUB to minimize the memory footprint. > > Thank you! > > Roman >