From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (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 82244E549; Fri, 2 Feb 2024 04:05:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706846713; cv=none; b=pEf18maCz62ErsJgI4knNR5EVI56hPbMM20FB3I/aCHJgSWYBLK7j9t1EgJUY/sgXY+X8OUfCAJenW/5g+M+xM5iHPxUZXQNXTbOqyYk3ZJW1U7yHAFgVMwzye1cypXvpYKcyuCSRmiJscVO2C06T6rbH+OHuhthYt1RxGP1bFo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706846713; c=relaxed/simple; bh=hZfxudAQbzcTFkLzrUZ/iFfqiq5eoB8LM/fFig+PAHA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uBMoMYYBb2zR97aJvt0THOGBr1gL4bsr3gTXc8ZQ11FxIVZw2Dex8yrD+tx+8Pme0IZn4cqNg60sqy5cMdqxNL09EOPdyYq8sayb2h6ktkS99RTxeO0kzbC+CUFAv/cqaII09sAUjfU+x+Bp51kJWOrvqPGk+6/V1MSmFcobhrc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=pIco9+AE; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="pIco9+AE" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=zprcRbdEZTEbzRJzXIqOfmdBLyrHEeb0z5ZjrW+eJjk=; b=pIco9+AEcGpi1eJkqd1+TWTTQ/ XggxqzL2w7JuIlqFb/qCdHy0ULmOVossWG+kEFJsaGwMh+RytusUgg82M15TvEDjlqwGslNf7cvUq sPt2Vassayxn3kWT9oVofZJaRl0DIN7pORLgWXb+9VTqqAlio+oguHQ5mP/B5DZuelRkEJdARnyFU m/G0i2qfxHjXcpG4x8OeVf8YUMVphbhJ7Uxp1eVbk/1W+xGbO+bqjutgFRWwu6i/wdiHFEvnCchz4 ZhCB1hItyVOF2KQdksSMyIe3+2vMkZTegZ2UOl9ci4kUZVIH/f16rNHViC/gdF6VL8VPSjwmx0o57 Hxxlk+WA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1rVknX-003e9i-0F; Fri, 02 Feb 2024 04:05:03 +0000 Date: Fri, 2 Feb 2024 04:05:03 +0000 From: Al Viro To: Doug Anderson Cc: Christian Brauner , Eric Biederman , Jan Kara , Kees Cook , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] regset: use vmalloc() for regset_get_alloc() Message-ID: <20240202040503.GX2087318@ZenIV> References: <20240201171159.1.Id9ad163b60d21c9e56c2d686b0cc9083a8ba7924@changeid> <20240202012249.GU2087318@ZenIV> <20240202030438.GV2087318@ZenIV> <20240202034925.GW2087318@ZenIV> 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=us-ascii Content-Disposition: inline In-Reply-To: <20240202034925.GW2087318@ZenIV> Sender: Al Viro On Fri, Feb 02, 2024 at 03:49:25AM +0000, Al Viro wrote: > On Thu, Feb 01, 2024 at 07:15:48PM -0800, Doug Anderson wrote: > > > > > > Well, the next step would be to see which regset it is - if you > > > see that kind of allocation, print regset->n, regset->size and > > > regset->core_note_type. > > > > Of course! Here are the big ones: > > > > [ 45.875574] DOUG: Allocating 279584 bytes, n=17474, size=16, > > core_note_type=1029 > > 0x405, NT_ARM_SVE > [REGSET_SVE] = { /* Scalable Vector Extension */ > .core_note_type = NT_ARM_SVE, > .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE), > SVE_VQ_BYTES), > .size = SVE_VQ_BYTES, > > IDGI. Wasn't SVE up to 32 * 2Kbit, i.e. 8Kbyte max? Any ARM folks around? > Sure, I understand that it's variable-sized and we want to allocate enough > for the worst case, but can we really get about 280Kb there? Context switches > would be really unpleasant on such boxen... FWIW, this apparently intends to be "variable, up to SVE_PT_SIZE(...) bytes"; no idea if SVE_PT_SIZE is the right thing to use here.