From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9B623C4451C for ; Tue, 21 Jul 2026 12:06:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=y4gKYq/LvdM4JrZj95BgJoCipIP0mRGi2upgSDBwFbA=; b=a3zz2f+WZpNdKK Pz7R3bg6vkQOHIhQ7vpIwCxyEK8JZ0rq9BngRmMc6BgKolbofKmuy9y23PfB054Ns6ARCgN8KKzbO JT1rmTSgYJ6SF3H0lJ6U0VkNfSqnJGCGtUtwf0FEzYKhcndDPQswoYynrzpLQcQzbjS1D+YiRzP2G +8MGqeThZKoHiPF8cwS1eMoM+qRHwBaLIJhJtysW5ttmHIcnxcrs3R56ZGlmLMwAe06OeodZ1d3IW rbWjlj88c54u349a4xOPlAcxOa/BQ2yqqV3DqeaE9SfIPCY8RGHxXE8PJIgJF9n+JHBYHx26KZd80 yPl4xJPSMIZR+8+jl2ew==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wm9Eg-00000009NOt-3qmk; Tue, 21 Jul 2026 12:06:10 +0000 Received: from out-188.mta1.migadu.com ([95.215.58.188]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wm9Ee-00000009NOJ-0uwa for linux-riscv@lists.infradead.org; Tue, 21 Jul 2026 12:06:09 +0000 Date: Tue, 21 Jul 2026 20:05:49 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1784635564; 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=A7dYAlxy/AmMUyH+MlvfhyBiS8Q0C6HxH/Mauukj/gQ=; b=eZwE3YxBH34e9tRiCPggwYdYaOw6NhkKu6BTNStYMe942ZxlIFt9cE8RPfN+rNf2WBfllB dRtZZhVUmLMxoo5O5g9KDUWfGfoIsGLousnSIDCtVH38WaSJPywwXrv5D8cF+wN4+r7uBQ iKjh+SXv0L25Chs5leSM8+RdGynHSSE= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Baoquan He To: Omar Sandoval Cc: Mike Rapoport , Pnina Feder , Simon Horman , Andrew Morton , Pasha Tatashin , Pratyush Yadav , Thomas Bogendoerfer , Paul Walmsley , Palmer Dabbelt , Albert Ou , Dave Young , Jonathan Corbet , Alexandre Ghiti , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-doc@vger.kernel.org, linux-debuggers@vger.kernel.org Subject: Re: [PATCH 0/4] vmcore-tasks: export per-task metadata to vmcoreinfo Message-ID: References: <20260622211430.4008899-1-pnina.feder@mobileye.com> <20260720091927.GA1736709@horms.kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260721_050608_603408_3C4A23CA X-CRM114-Status: GOOD ( 43.33 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org T24gMDcvMjAvMjYgYXQgMTA6MzVhbSwgT21hciBTYW5kb3ZhbCB3cm90ZToKPiBPbiBNb24sIEp1 bCAyMCwgMjAyNiBhdCAxMDo0MDo0M1BNICswODAwLCBCYW9xdWFuIEhlIHdyb3RlOgo+ID4gT24g MDcvMjAvMjYgYXQgMDM6NDNwbSwgTWlrZSBSYXBvcG9ydCB3cm90ZToKPiA+ID4gSGkgU2ltb24s Cj4gPiA+IAo+ID4gPiBPbiBNb24sIEp1bCAyMCwgMjAyNiBhdCAxMDoxOToyN0FNICswMTAwLCBT aW1vbiBIb3JtYW4gd3JvdGU6Cj4gPiA+ID4gT24gVHVlLCBKdWwgMDcsIDIwMjYgYXQgMDk6MjE6 NThBTSArMDMwMCwgTWlrZSBSYXBvcG9ydCB3cm90ZToKPiA+ID4gPiA+IE9uIFR1ZSwgSnVuIDIz LCAyMDI2IGF0IDEyOjE0OjI2QU0gKzAzMDAsIFBuaW5hIEZlZGVyIHdyb3RlOgo+ID4gPiA+ID4g PiBUaGlzIHNlcmllcyBleHRlbmRzIHZtY29yZWluZm8gd2l0aCBzdHJ1Y3Qgb2Zmc2V0cyBhbmQg c2l6ZXMgbmVlZGVkIGJ5Cj4gPiA+ID4gPiA+IHRoZSB2bWNvcmUtdGFza3MgdXNlcnNwYWNlIHRv b2wgdG8gZXh0cmFjdCBwZXItdGFzayBzdGF0ZSBmcm9tIGEgdm1jb3JlCj4gPiA+ID4gPiA+IGR1 bXAgd2l0aG91dCByZXF1aXJpbmcga2VybmVsIGRlYnVnIHN5bWJvbHMgKERXQVJGL0JURikuCj4g PiA+ID4gPiA+IAo+ID4gPiA+ID4gPiBUaGUgdm1jb3JlLXRhc2tzIHRvb2wgcmVhZHMgL3Byb2Mv dm1jb3JlIChvciBhIHNhdmVkIHZtY29yZSBmaWxlKSBhbmQKPiA+ID4gPiA+ID4gcmVjb25zdHJ1 Y3RzLCBmb3IgZWFjaCB0YXNrOgo+ID4gPiA+ID4gPiAgIC0gdGFzayBuYW1lLCBwaWQsIHN0YXRl LCBmbGFncwo+ID4gPiA+ID4gPiAgIC0gVk1BIGxpc3QgKHN0YXJ0LCBlbmQsIGZsYWdzLCBiYWNr aW5nIGZpbGUpCj4gPiA+ID4gPiA+ICAgLSB1c2VyIHJlZ2lzdGVyIHN0YXRlIChzYXZlZCBvbiB0 aGUga2VybmVsIHN0YWNrIGF0IGtlcm5lbCBlbnRyeSkKPiA+ID4gPiA+ID4gICAtIHVzZXItc3Bh Y2UgYmFja3RyYWNlIHdpdGggVk1BL2ZpbGVuYW1lIG1hcHBpbmcKPiA+ID4gPiA+ID4gICAtIGtl cm5lbCBkbWVzZyBidWZmZXIKPiA+ID4gPiA+ID4gCj4gPiA+ID4gPiA+IFRoaXMgcHJvdmlkZXMg YSBsaWdodHdlaWdodCBwb3N0LW1vcnRlbSBjcmFzaCBhbmFseXNpcyBjYXBhYmlsaXR5IGZvcgo+ ID4gPiA+ID4gPiBwcm9kdWN0aW9uIGVudmlyb25tZW50cyB3aGVyZSBmdWxsIGRlYnVnIGluZm8g KERXQVJGL0JURikgaXMgbm90Cj4gPiA+ID4gPiA+IGF2YWlsYWJsZS4KPiA+ID4gPiA+ID4gCj4g PiA+ID4gPiA+IFRoZSBjb21wYW5pb24gdXNlcnNwYWNlIHRvb2wgaXMgc3VibWl0dGVkIHRvIGtl eGVjLXRvb2xzOgo+ID4gPiA+ID4gPiAgIGh0dHBzOi8vbG9yZS5rZXJuZWwub3JnL2FsbC8yMDI2 MDYyMjIwNTU1MC4xMDg3MTYzLTEtcG5pbmEuZmVkZXJAbW9iaWxleWUuY29tLwo+ID4gPiA+ID4g Cj4gPiA+ID4gPiBTb3JyeSBmb3IgdGhlIGRlbGF5LCB0aGlzIGZlbGwgYmV0d2VlbiB0aGUgY3Jh Y2tzIHNvbWVob3cuCj4gPiA+ID4gPiAKPiA+ID4gPiA+IFRoZSBrZXJuZWwgc2lkZSBsb29rcyBm aW5lIG92ZXJhbGwsIGJ1dCB0byBtZXJnZSBpdCB0aGVyZSBzaG91bGQgYmUgYW4KPiA+ID4gPiA+ IGFncmVlbWVudCBmcm9tIHRoZSB1c2Vyc3BhY2Ugc2lkZSBtYWludGFpbmVycyB0aGF0IHZtY29y ZS10YXNrcyBpcwo+ID4gPiA+ID4gc29tZXRoaW5nIHRoZXkgYXJlIHdpc2hpbmcgdG8gYWNjZXB0 Lgo+ID4gPiA+IAo+ID4gPiA+IEhpIE1pa2UsIGFsbCwKPiA+ID4gPiAKPiA+ID4gPiBTb3JyeSBm b3IgdGhlIGV4dGVuZGVkIGRlbGF5Lgo+ID4gPiA+IAo+ID4gPiA+IEkgd2lsbCBzZW5kIHNvbWUg bWlub3IgZmVlZGJhY2sgdG8gdGhlIHVzZXItc3BhY2UgdG9vbCBwYXRjaHNldAo+ID4gPiA+IGJ1 dCBvdmVyYWxsLCB5ZXMsIHRoaXMgaXMgc29tZXRoaW5nIEkgd291bGQgYmUgaGFwcHkgdG8gYWNj ZXB0Lgo+ID4gPiA+IAo+ID4gPiA+IEkgZG9uJ3Qgd2FudCB0byBjcmVhdGUgYSBjaGlja2VuLWFu ZC1lZ2cgdHlwZSBwcm9ibGVtIGhlcmUuCj4gPiA+ID4gQnV0IGl0J3MgcHJvYmFibHkgd29ydGgg bWVudGlvbmluZyB0aGF0IHVzdWFsbHkgZmVhdHVyZXMKPiA+ID4gPiBoaXQgdGhlIGtlcm5lbCBi ZWZvcmUgdGhlIGNvcnJlc3BvbmRpbmcgY29kZSBpcyBhY2NlcHRlZAo+ID4gPiA+IGludG8ga2V4 ZWMtdG9vbHMuCj4gPiA+IAo+ID4gPiBTb3JyeSBpZiBJIHdhc24ndCBjbGVhci4gCj4gPiA+IAo+ ID4gPiBJIGRpZG4ndCBtZWFuIHRoYXQgdGhlIGZlYXR1cmUgc2hvdWxkIGJlIG1lcmdlZCBpbnRv IGtleGVjLXRvb2xzIGJlZm9yZQo+ID4gPiBtZXJnaW5nIHRoZSBrZXJuZWwgYml0cy4gSSBqdXN0 IHdhbnRlZCB0byBtYWtlIHN1cmUgdGhlcmUncyBubyBmdW5kYW1lbnRhbAo+ID4gPiBpc3N1ZSBm cm9tIGtleGVjLXRvb2xzIHBlcnNwZWN0aXZlLgo+ID4gPiAKPiA+ID4gPiBMZXQgbWUga25vdyBo b3cgeW91IHdvdWxkIGxpa2UgdG8gcHJvY2VlZC4KPiA+ID4gCj4gPiA+IEknbSBnb2luZyB0byB3 YWl0IGZvciBCYW9xdWFuJ3MgcmV2aWV3IGFuZCBvbmNlIHRoYXQncyBkb25lIEknbGwgcGljayB1 cAo+ID4gPiB0aGUga2VybmVsIGJpdHMuCj4gPiAKPiA+IE9oLCBzb3JyeSwgSSBqdXN0IG5vdGlj ZWQgdGhpcyBzZXJpZXMsIGJ1dCBhIHF1aWNrIGxvb2sgZ2l2ZSBtZSBhIGhpbnQKPiA+IG9mICdO bywgSSBkb24ndCBsaWtlIGl0LicgV2UgaGF2ZSBoYWQgQ3Jhc2ggdXRpbGl0eSwgRHJnbiwgbm93 IGEgbmV3IG9uZQo+ID4gY29tZXMgdXAuIEkgaGF2ZSBzb21lIGNvbmNlcm5zIHRvIFBuaW5hOgo+ ID4gCj4gPiAxLiBFeHBvcnRpbmcgbWFwbGUgdHJlZSBpbnRlcm5hbHMgKG1hcGxlX25vZGUsIG1h cGxlX3JhbmdlXzY0LAo+ID4gICAgbWFwbGVfYXJhbmdlXzY0LCBtYXBsZV9tZXRhZGF0YSkgYXMg dm1jb3JlaW5mbyBBQkkgaXMgcHJvYmxlbWF0aWMuCj4gPiAgICBUaGVzZSBhcmUgcHJpdmF0ZSBp bXBsZW1lbnRhdGlvbiBkZXRhaWxzLCBub3Qgc3RhYmxlIHN0cnVjdHVyZXMgbGlrZQo+ID4gICAg dGFza19zdHJ1Y3QuIEFueSByZWZhY3RvcmluZyBvZiB0aGUgbWFwbGUgdHJlZSB3aWxsIHNpbGVu dGx5IGJyZWFrCj4gPiAgICB0aGUgdXNlcnNwYWNlIHRvb2wuIAo+ID4gCj4gPiAyLiBXaXRob3V0 IERXQVJGL0JURiwgdGhlIGRlYnVnZ2luZyBzY29wZSBpcyBpbmhlcmVudGx5IGxpbWl0ZWQg4oCU IG5vCj4gPiAgICBrZXJuZWwgc3RhY2sgYmFja3RyYWNlLCBubyBzeW1ib2wgcmVzb2x1dGlvbiwg bm8gdmFyaWFibGUgYWNjZXNzLgo+ID4gICAgVGhhdCdzIGVzc2VudGlhbGx5ICJwcyArIC9wcm9j L1BJRC9tYXBzIiBmcm9tIGEgdm1jb3JlLiBIYXZlIHlvdQo+ID4gICAgY29uc2lkZXJlZCBlbmFi bGluZyBDT05GSUdfREVCVUdfSU5GT19CVEYgb24geW91ciBwbGF0Zm9ybXMgaW5zdGVhZD8KPiA+ ICAgIEJURiBpcyBjb21wYWN0ICh0eXBpY2FsbHkgPCAxIE1CKSBhbmQgd291bGQgZ2l2ZSBkcmdu IGZ1bGwgYWNjZXNzCj4gPiAgICB3aXRob3V0IG5lZWRpbmcgdm1saW51eCBkZWJ1ZyBwYWNrYWdl cy4gVGhhdCBzZWVtcyBsaWtlIGEgYmV0dGVyCj4gPiAgICByZXR1cm4tb24taW52ZXN0bWVudCB0 aGFuIG1haW50YWluaW5nIH40MCBuZXcgdm1jb3JlaW5mbyBleHBvcnRzLgo+ID4gCj4gPiAzLiBC ZXlvbmQgdGhlIHRlY2huaWNhbCBjb25jZXJucywgSSB3b25kZXIgYWJvdXQgYWRvcHRpb24uIHZt Y29yZS10YXNrcwo+ID4gICAgdGFyZ2V0cyBhIGZhaXJseSBuYXJyb3cgdXNlIGNhc2Ug4oCUIHBs YXRmb3JtcyB3aXRob3V0IERXQVJGL0JURiwgd2hlcmUKPiA+ICAgIHlvdSBzdGlsbCBoYXZlIHZt Y29yZSBidXQgY2FuJ3Qgc2hpcCB2bWxpbnV4LiBJcyBNb2JpbGV5ZSBjdXJyZW50bHkKPiA+ICAg IHRoZSBvbmx5IGNvbnN1bWVyPyBBcmUgeW91IGd1eXMgYWxyZWFkeSB1c2luZyBpdCB3aWRlbHkg YW5kIGZ1bGx5Pwo+ID4gICAgSWYgdGhpcyBsYW5kcyBidXQgZG9lc24ndCBzZWUgYnJvYWRlciB1 cHRha2UsIHRoZSB+NDAgZXhwb3J0cyByaXNrCj4gPiAgICBiZWNvbWluZyBkZWFkIHdlaWdodCBp biB2bWNvcmVpbmZvIOKAlCBub2JvZHkgYWN0aXZlbHkgdXNlcyB0aGVtLCBidXQKPiA+ICAgIGtl cm5lbCBjaGFuZ2VzIHN0aWxsIG5lZWQgdG8ga2VlcCB0aGVtIGNvbnNpc3RlbnQsIG9yIHRoZXkg c2lsZW50bHkKPiA+ICAgIHJvdCBhbmQgZ2l2ZSB1c2VycyB3cm9uZyByZXN1bHRzLiAKPiA+IAo+ ID4gUmVnYXJkcywKPiA+IEJhb3F1YW4KPiAKPiAoQWRkaW5nIGxpbnV4LWRlYnVnZ2VycyBtYWls aW5nIGxpc3QpLgo+IAo+IEkgYWdyZWUgd2l0aCBhbGwgb2YgQmFvcXVhbidzIHBvaW50cyBoZXJl LCB3aXRoIGEgY291cGxlIG9mIG5vdGVzOgo+IAo+IDEuIGRyZ24ncyBCVEYgc3VwcG9ydCBpcyBj dXJyZW50bHkgYSB3b3JrIGluIHByb2dyZXNzLCBidXQgaXQncyBzaGFwaW5nCj4gICAgdXAgd2Vs bDogaHR0cHM6Ly9naXRodWIuY29tL29zYW5kb3YvZHJnbi9wdWxsLzYyNS4KPiAyLiBtYWtlZHVt cGZpbGUgaXMgYWxzbyBnYWluaW5nIEJURiBleHRlbnNpb24gc3VwcG9ydDoKPiAgICBodHRwczov L2xvcmUua2VybmVsLm9yZy9hbGwvMjAyNjA2MTcwNTE4MzQuOTU0MDQtMS1sdGFvQHJlZGhhdC5j b20vLgo+ICAgIEl0J3MgbGlnaHRlci13ZWlnaHQgdGhhbiBkcmduIHdoaWxlIHN0aWxsIGJlaW5n IG11Y2ggbW9yZSBnZW5lcmFsCj4gICAgdGhhbiB0aGlzIHNlcmllcy4KClRoYW5rcyBmb3IgYWRk aW5nIHRoZSBpbmZvcm1hdGlvbiwgdmVyeSBoZWxwZnVsLgoKCl9fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fCmxpbnV4LXJpc2N2IG1haWxpbmcgbGlzdApsaW51 eC1yaXNjdkBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21h aWxtYW4vbGlzdGluZm8vbGludXgtcmlzY3YK From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) (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 6C0EB48C408 for ; Tue, 21 Jul 2026 12:06:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784635578; cv=none; b=GKQCIoPli00OHdtuEFs8Lf+HSB7aMANvQ2WZHXkLRtefeFRpS1v3KA8qRrLEm/JWlzL85UivOV4Gsyz06zvmuvqMhYXDxHAyRORJ1w8X0ajmmiTZPvEqObd1Pt8GMZ1N3tWhKWip1WuLediB57GsE/ZzB2V8kTjETIpFMx2BnJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784635578; c=relaxed/simple; bh=3oupU7+5mQICPbOMW24bukRFFTm81wEOBpej2miz2tE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hz4UkaCtdriE3G/dve9HaaqENjZjaLjR30hc4Fc09Z5NsSQntootcmjSmXjKPoFohzW/7bWir8Yo35lJnLGNJJFfjyKRfU7/S1GFBqHB4rb9+LXZsWCSSA61yHI/UNHQsSkJiQuOqfaL9+ZCucxvRCNfKy6FW6nepGhhL/KlWng= 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=eZwE3YxB; arc=none smtp.client-ip=95.215.58.180 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="eZwE3YxB" Date: Tue, 21 Jul 2026 20:05:49 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1784635564; 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=A7dYAlxy/AmMUyH+MlvfhyBiS8Q0C6HxH/Mauukj/gQ=; b=eZwE3YxBH34e9tRiCPggwYdYaOw6NhkKu6BTNStYMe942ZxlIFt9cE8RPfN+rNf2WBfllB dRtZZhVUmLMxoo5O5g9KDUWfGfoIsGLousnSIDCtVH38WaSJPywwXrv5D8cF+wN4+r7uBQ iKjh+SXv0L25Chs5leSM8+RdGynHSSE= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Baoquan He To: Omar Sandoval Cc: Mike Rapoport , Pnina Feder , Simon Horman , Andrew Morton , Pasha Tatashin , Pratyush Yadav , Thomas Bogendoerfer , Paul Walmsley , Palmer Dabbelt , Albert Ou , Dave Young , Jonathan Corbet , Alexandre Ghiti , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-doc@vger.kernel.org, linux-debuggers@vger.kernel.org Subject: Re: [PATCH 0/4] vmcore-tasks: export per-task metadata to vmcoreinfo Message-ID: References: <20260622211430.4008899-1-pnina.feder@mobileye.com> <20260720091927.GA1736709@horms.kernel.org> Precedence: bulk X-Mailing-List: linux-doc@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 07/20/26 at 10:35am, Omar Sandoval wrote: > On Mon, Jul 20, 2026 at 10:40:43PM +0800, Baoquan He wrote: > > On 07/20/26 at 03:43pm, Mike Rapoport wrote: > > > Hi Simon, > > > > > > On Mon, Jul 20, 2026 at 10:19:27AM +0100, Simon Horman wrote: > > > > On Tue, Jul 07, 2026 at 09:21:58AM +0300, Mike Rapoport wrote: > > > > > On Tue, Jun 23, 2026 at 12:14:26AM +0300, Pnina Feder wrote: > > > > > > This series extends vmcoreinfo with struct offsets and sizes needed by > > > > > > the vmcore-tasks userspace tool to extract per-task state from a vmcore > > > > > > dump without requiring kernel debug symbols (DWARF/BTF). > > > > > > > > > > > > The vmcore-tasks tool reads /proc/vmcore (or a saved vmcore file) and > > > > > > reconstructs, for each task: > > > > > > - task name, pid, state, flags > > > > > > - VMA list (start, end, flags, backing file) > > > > > > - user register state (saved on the kernel stack at kernel entry) > > > > > > - user-space backtrace with VMA/filename mapping > > > > > > - kernel dmesg buffer > > > > > > > > > > > > This provides a lightweight post-mortem crash analysis capability for > > > > > > production environments where full debug info (DWARF/BTF) is not > > > > > > available. > > > > > > > > > > > > The companion userspace tool is submitted to kexec-tools: > > > > > > https://lore.kernel.org/all/20260622205550.1087163-1-pnina.feder@mobileye.com/ > > > > > > > > > > Sorry for the delay, this fell between the cracks somehow. > > > > > > > > > > The kernel side looks fine overall, but to merge it there should be an > > > > > agreement from the userspace side maintainers that vmcore-tasks is > > > > > something they are wishing to accept. > > > > > > > > Hi Mike, all, > > > > > > > > Sorry for the extended delay. > > > > > > > > I will send some minor feedback to the user-space tool patchset > > > > but overall, yes, this is something I would be happy to accept. > > > > > > > > I don't want to create a chicken-and-egg type problem here. > > > > But it's probably worth mentioning that usually features > > > > hit the kernel before the corresponding code is accepted > > > > into kexec-tools. > > > > > > Sorry if I wasn't clear. > > > > > > I didn't mean that the feature should be merged into kexec-tools before > > > merging the kernel bits. I just wanted to make sure there's no fundamental > > > issue from kexec-tools perspective. > > > > > > > Let me know how you would like to proceed. > > > > > > I'm going to wait for Baoquan's review and once that's done I'll pick up > > > the kernel bits. > > > > Oh, sorry, I just noticed this series, but a quick look give me a hint > > of 'No, I don't like it.' We have had Crash utility, Drgn, now a new one > > comes up. I have some concerns to Pnina: > > > > 1. Exporting maple tree internals (maple_node, maple_range_64, > > maple_arange_64, maple_metadata) as vmcoreinfo ABI is problematic. > > These are private implementation details, not stable structures like > > task_struct. Any refactoring of the maple tree will silently break > > the userspace tool. > > > > 2. Without DWARF/BTF, the debugging scope is inherently limited — no > > kernel stack backtrace, no symbol resolution, no variable access. > > That's essentially "ps + /proc/PID/maps" from a vmcore. Have you > > considered enabling CONFIG_DEBUG_INFO_BTF on your platforms instead? > > BTF is compact (typically < 1 MB) and would give drgn full access > > without needing vmlinux debug packages. That seems like a better > > return-on-investment than maintaining ~40 new vmcoreinfo exports. > > > > 3. Beyond the technical concerns, I wonder about adoption. vmcore-tasks > > targets a fairly narrow use case — platforms without DWARF/BTF, where > > you still have vmcore but can't ship vmlinux. Is Mobileye currently > > the only consumer? Are you guys already using it widely and fully? > > If this lands but doesn't see broader uptake, the ~40 exports risk > > becoming dead weight in vmcoreinfo — nobody actively uses them, but > > kernel changes still need to keep them consistent, or they silently > > rot and give users wrong results. > > > > Regards, > > Baoquan > > (Adding linux-debuggers mailing list). > > I agree with all of Baoquan's points here, with a couple of notes: > > 1. drgn's BTF support is currently a work in progress, but it's shaping > up well: https://github.com/osandov/drgn/pull/625. > 2. makedumpfile is also gaining BTF extension support: > https://lore.kernel.org/all/20260617051834.95404-1-ltao@redhat.com/. > It's lighter-weight than drgn while still being much more general > than this series. Thanks for adding the information, very helpful.