From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) (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 BEA8831E82A for ; Mon, 29 Jun 2026 19:53:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782762788; cv=none; b=jlR/e+CaadbsBdRN1lYLOVYzWoYtrDlVkzPHH8DNV2ShXGfWlzG1u2mwl9qFaYys/jsWppaZzbRYadLVr6rGNoG+Rh47rQLPHXwwyA6GoHSviOYGOsJHdoc1x46vE+uJXOXEy7dcmI9x+lWyL6wQBwBqVAQQFa7ihpb1emJWr6o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782762788; c=relaxed/simple; bh=eNyPam/FsnkzGAwne7t+tXMAiXG74erD3skBxsmre2o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=flFqqAGxPPfVwICEmSNm4ktDqNHR+BDfQcDTTdTvjTr5fvFbWmDqg6rL+Um7IK7yfzUP0dAxIF4hlKNrm4o4Un/R6Bb25phs+amNmHVkaATykB4WDj/fPW2tEBStr45i3uper1pKpnfeM83vQYW7bvojjlM+yhWK86e4w02rS5I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=arGrTuiI; arc=none smtp.client-ip=95.215.58.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="arGrTuiI" Date: Mon, 29 Jun 2026 12:52:52 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1782762782; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eNyPam/FsnkzGAwne7t+tXMAiXG74erD3skBxsmre2o=; b=arGrTuiIVCZPpfVOVWxqJXYrvPgtzqxDl2sH0/LDKUUHDu8YyRFkAO04t5PQRnBTwHWPgv wGsLDBkXPkqwXmZfklhBidCtnzSwhuCirgEqFtEviEIzVWX9v4143rT3FCUnXZCm3coXQu ifUIbT3h5J+yGW/qW6vrAkGfBtqNZAU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Shakeel Butt To: Suren Baghdasaryan Cc: Harry Yoo , "Vlastimil Babka (SUSE)" , Andrew Morton , Roman Gushchin , Hao Li , Christoph Lameter , David Rientjes , Usama Arif , Meta kernel team , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Danielle Costantino , Kees Cook Subject: Re: [PATCH] mm/slub: serve slabobj_ext array from a strictly larger kmalloc cache Message-ID: References: <62453403-954c-4cf1-8924-6d38184b0810@kernel.org> <09267187-6c85-438f-8791-4cce8d07892a@kernel.org> <68122038-e8e0-47ed-82f8-cb6a23e4658e@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Migadu-Flow: FLOW_OUT On Sun, Jun 28, 2026 at 09:28:51PM -0700, Suren Baghdasaryan wrote: > On Sun, Jun 28, 2026 at 8:57 PM Harry Yoo wrote: > > > > [...] Thanks all for great discussion. Let me summarize the conclusion and please correct me if I missed something. Let's keep the original one-line fix (serve the obj_exts array from a strictly larger cache, making the relation a DAG). We will NOT gate it on mem_alloc_profiling_enabled() as I floated earlier -- per Harry, is_kmalloc_normal(s) is already the right condition, and gating on profiling would miss the SLUB_TINY + __GFP_RECLAIMABLE|__GFP_ACCOUNT memcg case. So the bump stays unconditional for is_kmalloc_normal() caches. This over-allocates the array for larger caches, but only for profiling and SLUB_TINY+MEMCG users (the latter unrealistic). Acceptable for a small, backportable fix. thanks, Shakeel