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 DFFAAC7EE2A for ; Wed, 25 Jun 2025 18:43:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lY4C+H8rjCf0tB+LlRLUjdQXLKGrHdCeK+5aYVx8K34=; b=XkutpV5OTqYO/u22E42q2oexHN nUDO1q17+hhyCyCZRzCcf41kazszRkYmaHpfcVYPkkPD5pDbnJXOf7uCxNjDfRcW592l5cezlpd16 OEhio9RVMHrMVeLiucJcfCVLyCQQE7OuPjPc+27jUd16InetE0WRGRC9PqQ2hoEMOszwkCTZwyNzL XdHhF+XuUxlnODLwAF/MNkEr1coSLYdLrL+EP4mGfxKRlOIV+dYbGkZPLPE8wwrSFKvcU0CoCXQan KnnuRW/x90UL6bE+D+9BzudyAdUgU7tNDVdQAChyOq9xCMSb/Kv8bSw07VAfOW/Vea4dGML4I2ZzS rtAfUL2A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUV5Q-00000009ddM-2qhG; Wed, 25 Jun 2025 18:43:08 +0000 Received: from out-172.mta1.migadu.com ([95.215.58.172]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUPhy-00000008iRd-0n6v; Wed, 25 Jun 2025 12:58:35 +0000 Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1750856311; 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=lY4C+H8rjCf0tB+LlRLUjdQXLKGrHdCeK+5aYVx8K34=; b=H0RQVztbREsh2CeBNzfiHRG3ArsNptNh9e4vAD7piCsogyawFZAZ0h7oX5wxSxKudfeOx8 zmgi8lKBBJDJyX+yA3Bd/pjb8f4zMM6qXYyQr+ccBk4iLesagodds3gfB2bKoUezfMEyH5 9KebcsTF3oF2ez4v96G72qSVlbShipA= Date: Wed, 25 Jun 2025 20:58:12 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v4 3/4] mm: Support batched unmap for lazyfree large folios during reclamation Content-Language: en-US To: David Hildenbrand , Barry Song <21cnbao@gmail.com> Cc: akpm@linux-foundation.org, baolin.wang@linux.alibaba.com, chrisl@kernel.org, kasong@tencent.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, lorenzo.stoakes@oracle.com, ryan.roberts@arm.com, v-songbaohua@oppo.com, x86@kernel.org, ying.huang@intel.com, zhengtangquan@oppo.com, Lance Yang References: <2c19a6cf-0b42-477b-a672-ed8c1edd4267@redhat.com> <20250624162503.78957-1-ioworker0@gmail.com> <27d174e0-c209-4851-825a-0baeb56df86f@redhat.com> <938c4726-b93e-46df-bceb-65c7574714a6@linux.dev> <5ba95609-302b-456a-a863-2bd5df51baf2@redhat.com> <6179dd30-5351-4a79-b0d6-f0e85650a926@redhat.com> <5db6fb4c-079d-4237-80b3-637565457f39@redhat.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <5db6fb4c-079d-4237-80b3-637565457f39@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250625_055834_681578_4EFA53C6 X-CRM114-Status: GOOD ( 26.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2025/6/25 20:09, David Hildenbrand wrote: > On 25.06.25 13:42, Barry Song wrote: >> On Wed, Jun 25, 2025 at 11:27 PM David Hildenbrand >> wrote: >>> >>> On 25.06.25 13:15, Barry Song wrote: >>>> On Wed, Jun 25, 2025 at 11:01 PM David Hildenbrand >>>> wrote: >>>>> >>>>> On 25.06.25 12:57, Barry Song wrote: >>>>>>>> >>>>>>>> Note that I don't quite understand why we have to batch the >>>>>>>> whole thing >>>>>>>> or fallback to >>>>>>>> individual pages. Why can't we perform other batches that span >>>>>>>> only some >>>>>>>> PTEs? What's special >>>>>>>> about 1 PTE vs. 2 PTEs vs. all PTEs? >>>>>>> >>>>>>> That's a good point about the "all-or-nothing" batching logic ;) >>>>>>> >>>>>>> It seems the "all-or-nothing" approach is specific to the >>>>>>> lazyfree use >>>>>>> case, which needs to unmap the entire folio for reclamation. If >>>>>>> that's >>>>>>> not possible, it falls back to the single-page slow path. >>>>>> >>>>>> Other cases advance the PTE themselves, while try_to_unmap_one() >>>>>> relies >>>>>> on page_vma_mapped_walk() to advance the PTE. Unless we want to >>>>>> manually >>>>>> modify pvmw.pte and pvmw.address outside of >>>>>> page_vma_mapped_walk(), which >>>>>> to me seems like a violation of layers. :-) >>>>> >>>>> Please explain to me why the following is not clearer and better: >>>> >>>> This part is much clearer, but that doesn’t necessarily improve the >>>> overall >>>> picture. The main challenge is how to exit the iteration of >>>> while (page_vma_mapped_walk(&pvmw)). >>> >>> Okay, I get what you mean now. >>> >>>> >>>> Right now, we have it laid out quite straightforwardly: >>>>                   /* We have already batched the entire folio */ >>>>                   if (nr_pages > 1) >>>>                           goto walk_done; >>> >>> >>> Given that the comment is completely confusing whens seeing the >>> check ... :) >>> >>> /* >>>    * If we are sure that we batched the entire folio and cleared all >>> PTEs, >>>    * we can just optimize and stop right here. >>>    */ >>> if (nr_pages == folio_nr_pages(folio)) >>>          goto walk_done; >>> >>> would make the comment match. >> >> Yes, that clarifies it. >> >>> >>>> >>>> with any nr between 1 and folio_nr_pages(), we have to consider two >>>> issues: >>>> 1. How to skip PTE checks inside page_vma_mapped_walk for entries that >>>> were already handled in the previous batch; >>> >>> They are cleared if we reach that point. So the pte_none() checks will >>> simply skip them? >>> >>>> 2. How to break the iteration when this batch has arrived at the end. >>> >>> page_vma_mapped_walk() should be doing that? >> >> It seems you might have missed the part in my reply that says: >> "Of course, we could avoid both, but that would mean performing >> unnecessary >> checks inside page_vma_mapped_walk()." > > > That’s true for both. But I’m wondering why we’re still doing the > check, >> even when we’re fairly sure they’ve already been cleared or we’ve reached >> the end :-) > > :) > >> >> Somehow, I feel we could combine your cleanup code—which handles a batch >> size of "nr" between 1 and nr_pages—with the >> "if (nr_pages == folio_nr_pages(folio)) goto walk_done" check. > > Yeah, that's what I was suggesting. It would have to be part of the > cleanup I think. > > I'm still wondering if there is a case where > > if (nr_pages == folio_nr_pages(folio)) >     goto walk_done; > > would be wrong when dealing with small folios. We can make the check more explicit to avoid any future trouble ;) if (nr_pages > 1 && nr_pages == folio_nr_pages(folio)) goto walk_done; It should be safe for small folios. Thanks, Lance > >> In practice, this would let us skip almost all unnecessary checks, >> except for a few rare corner cases. >> >> For those corner cases where "nr" truly falls between 1 and nr_pages, >> we can just leave them as-is—performing the redundant check inside >> page_vma_mapped_walk(). > > I mean, batching mapcount+refcount updates etc. is always a win. If we > end up doing some unnecessary pte_none() checks, that might be > suboptimal but mostly noise in contrast to the other stuff we will > optimize out :) > > Agreed that if we can easily avoid these pte_none() checks, we should do > that. Optimizing that for "nr_pages == folio_nr_pages(folio)" makes sense. > 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 090C4C7EE31 for ; Wed, 25 Jun 2025 17:36:57 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uHnWJLUtcsDBfbl3IORSWH4vv53ajCRDEOs9vkdrOTg=; b=WsQb6P+p7KZM9X 41n2OjX99+azMYpryctUL3/ixhcpdc3CiZxSfOiU3t8A+zFhPOLZV/aiAVwwgKJo8Z4KvPLnlDgUt S5cS95v4qiYQukE1/RlvsPBAeb3E7r8lE9OizZ9bfLFkJYqNz+3+8d+rYKASVw/Rf9UV5KzRgErhX 9qC/DlX2tdt6ISRCy++u5oBOUPKV4ZlzDRO7Mb4eQKV4gBr2PX2ynDXWlxPOvnz919z6orNCiQujA XLDsNOD/BPs0yjLL04SPyW5o7zFz8PWi7PCb61+t3Zv/+yN3Ix6F8cisAXnFavgirBel1lzYJ5IKD ouaeevNvX00j6hqIaf+A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUU3G-00000009TLY-0M11; Wed, 25 Jun 2025 17:36:50 +0000 Received: from out-172.mta1.migadu.com ([95.215.58.172]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uUPhy-00000008iRd-0n6v; Wed, 25 Jun 2025 12:58:35 +0000 Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1750856311; 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=lY4C+H8rjCf0tB+LlRLUjdQXLKGrHdCeK+5aYVx8K34=; b=H0RQVztbREsh2CeBNzfiHRG3ArsNptNh9e4vAD7piCsogyawFZAZ0h7oX5wxSxKudfeOx8 zmgi8lKBBJDJyX+yA3Bd/pjb8f4zMM6qXYyQr+ccBk4iLesagodds3gfB2bKoUezfMEyH5 9KebcsTF3oF2ez4v96G72qSVlbShipA= Date: Wed, 25 Jun 2025 20:58:12 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v4 3/4] mm: Support batched unmap for lazyfree large folios during reclamation Content-Language: en-US To: David Hildenbrand , Barry Song <21cnbao@gmail.com> Cc: akpm@linux-foundation.org, baolin.wang@linux.alibaba.com, chrisl@kernel.org, kasong@tencent.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, lorenzo.stoakes@oracle.com, ryan.roberts@arm.com, v-songbaohua@oppo.com, x86@kernel.org, ying.huang@intel.com, zhengtangquan@oppo.com, Lance Yang References: <2c19a6cf-0b42-477b-a672-ed8c1edd4267@redhat.com> <20250624162503.78957-1-ioworker0@gmail.com> <27d174e0-c209-4851-825a-0baeb56df86f@redhat.com> <938c4726-b93e-46df-bceb-65c7574714a6@linux.dev> <5ba95609-302b-456a-a863-2bd5df51baf2@redhat.com> <6179dd30-5351-4a79-b0d6-f0e85650a926@redhat.com> <5db6fb4c-079d-4237-80b3-637565457f39@redhat.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <5db6fb4c-079d-4237-80b3-637565457f39@redhat.com> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250625_055834_681578_4EFA53C6 X-CRM114-Status: GOOD ( 26.37 ) 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-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org CgpPbiAyMDI1LzYvMjUgMjA6MDksIERhdmlkIEhpbGRlbmJyYW5kIHdyb3RlOgo+IE9uIDI1LjA2 LjI1IDEzOjQyLCBCYXJyeSBTb25nIHdyb3RlOgo+PiBPbiBXZWQsIEp1biAyNSwgMjAyNSBhdCAx MToyN+KAr1BNIERhdmlkIEhpbGRlbmJyYW5kIDxkYXZpZEByZWRoYXQuY29tPiAKPj4gd3JvdGU6 Cj4+Pgo+Pj4gT24gMjUuMDYuMjUgMTM6MTUsIEJhcnJ5IFNvbmcgd3JvdGU6Cj4+Pj4gT24gV2Vk LCBKdW4gMjUsIDIwMjUgYXQgMTE6MDHigK9QTSBEYXZpZCBIaWxkZW5icmFuZCAKPj4+PiA8ZGF2 aWRAcmVkaGF0LmNvbT4gd3JvdGU6Cj4+Pj4+Cj4+Pj4+IE9uIDI1LjA2LjI1IDEyOjU3LCBCYXJy eSBTb25nIHdyb3RlOgo+Pj4+Pj4+Pgo+Pj4+Pj4+PiBOb3RlIHRoYXQgSSBkb24ndCBxdWl0ZSB1 bmRlcnN0YW5kIHdoeSB3ZSBoYXZlIHRvIGJhdGNoIHRoZSAKPj4+Pj4+Pj4gd2hvbGUgdGhpbmcK Pj4+Pj4+Pj4gb3IgZmFsbGJhY2sgdG8KPj4+Pj4+Pj4gaW5kaXZpZHVhbCBwYWdlcy4gV2h5IGNh bid0IHdlIHBlcmZvcm0gb3RoZXIgYmF0Y2hlcyB0aGF0IHNwYW4gCj4+Pj4+Pj4+IG9ubHkgc29t ZQo+Pj4+Pj4+PiBQVEVzPyBXaGF0J3Mgc3BlY2lhbAo+Pj4+Pj4+PiBhYm91dCAxIFBURSB2cy4g MiBQVEVzIHZzLiBhbGwgUFRFcz8KPj4+Pj4+Pgo+Pj4+Pj4+IFRoYXQncyBhIGdvb2QgcG9pbnQg YWJvdXQgdGhlICJhbGwtb3Itbm90aGluZyIgYmF0Y2hpbmcgbG9naWMgOykKPj4+Pj4+Pgo+Pj4+ Pj4+IEl0IHNlZW1zIHRoZSAiYWxsLW9yLW5vdGhpbmciIGFwcHJvYWNoIGlzIHNwZWNpZmljIHRv IHRoZSAKPj4+Pj4+PiBsYXp5ZnJlZSB1c2UKPj4+Pj4+PiBjYXNlLCB3aGljaCBuZWVkcyB0byB1 bm1hcCB0aGUgZW50aXJlIGZvbGlvIGZvciByZWNsYW1hdGlvbi4gSWYgCj4+Pj4+Pj4gdGhhdCdz Cj4+Pj4+Pj4gbm90IHBvc3NpYmxlLCBpdCBmYWxscyBiYWNrIHRvIHRoZSBzaW5nbGUtcGFnZSBz bG93IHBhdGguCj4+Pj4+Pgo+Pj4+Pj4gT3RoZXIgY2FzZXMgYWR2YW5jZSB0aGUgUFRFIHRoZW1z ZWx2ZXMsIHdoaWxlIHRyeV90b191bm1hcF9vbmUoKSAKPj4+Pj4+IHJlbGllcwo+Pj4+Pj4gb24g cGFnZV92bWFfbWFwcGVkX3dhbGsoKSB0byBhZHZhbmNlIHRoZSBQVEUuIFVubGVzcyB3ZSB3YW50 IHRvIAo+Pj4+Pj4gbWFudWFsbHkKPj4+Pj4+IG1vZGlmeSBwdm13LnB0ZSBhbmQgcHZtdy5hZGRy ZXNzIG91dHNpZGUgb2YgCj4+Pj4+PiBwYWdlX3ZtYV9tYXBwZWRfd2FsaygpLCB3aGljaAo+Pj4+ Pj4gdG8gbWUgc2VlbXMgbGlrZSBhIHZpb2xhdGlvbiBvZiBsYXllcnMuIDotKQo+Pj4+Pgo+Pj4+ PiBQbGVhc2UgZXhwbGFpbiB0byBtZSB3aHkgdGhlIGZvbGxvd2luZyBpcyBub3QgY2xlYXJlciBh bmQgYmV0dGVyOgo+Pj4+Cj4+Pj4gVGhpcyBwYXJ0IGlzIG11Y2ggY2xlYXJlciwgYnV0IHRoYXQg ZG9lc27igJl0IG5lY2Vzc2FyaWx5IGltcHJvdmUgdGhlIAo+Pj4+IG92ZXJhbGwKPj4+PiBwaWN0 dXJlLiBUaGUgbWFpbiBjaGFsbGVuZ2UgaXMgaG93IHRvIGV4aXQgdGhlIGl0ZXJhdGlvbiBvZgo+ Pj4+IHdoaWxlIChwYWdlX3ZtYV9tYXBwZWRfd2FsaygmcHZtdykpLgo+Pj4KPj4+IE9rYXksIEkg Z2V0IHdoYXQgeW91IG1lYW4gbm93Lgo+Pj4KPj4+Pgo+Pj4+IFJpZ2h0IG5vdywgd2UgaGF2ZSBp dCBsYWlkIG91dCBxdWl0ZSBzdHJhaWdodGZvcndhcmRseToKPj4+PiDCoMKgwqDCoMKgwqDCoMKg wqDCoMKgwqDCoMKgwqDCoMKgIC8qIFdlIGhhdmUgYWxyZWFkeSBiYXRjaGVkIHRoZSBlbnRpcmUg Zm9saW8gKi8KPj4+PiDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgIGlmIChucl9w YWdlcyA+IDEpCj4+Pj4gwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKg wqDCoMKgwqAgZ290byB3YWxrX2RvbmU7Cj4+Pgo+Pj4KPj4+IEdpdmVuIHRoYXQgdGhlIGNvbW1l bnQgaXMgY29tcGxldGVseSBjb25mdXNpbmcgd2hlbnMgc2VlaW5nIHRoZSAKPj4+IGNoZWNrIC4u LiA6KQo+Pj4KPj4+IC8qCj4+PiDCoMKgICogSWYgd2UgYXJlIHN1cmUgdGhhdCB3ZSBiYXRjaGVk IHRoZSBlbnRpcmUgZm9saW8gYW5kIGNsZWFyZWQgYWxsIAo+Pj4gUFRFcywKPj4+IMKgwqAgKiB3 ZSBjYW4ganVzdCBvcHRpbWl6ZSBhbmQgc3RvcCByaWdodCBoZXJlLgo+Pj4gwqDCoCAqLwo+Pj4g aWYgKG5yX3BhZ2VzID09IGZvbGlvX25yX3BhZ2VzKGZvbGlvKSkKPj4+IMKgwqDCoMKgwqDCoMKg wqAgZ290byB3YWxrX2RvbmU7Cj4+Pgo+Pj4gd291bGQgbWFrZSB0aGUgY29tbWVudCBtYXRjaC4K Pj4KPj4gWWVzLCB0aGF0IGNsYXJpZmllcyBpdC4KPj4KPj4+Cj4+Pj4KPj4+PiB3aXRoIGFueSBu ciBiZXR3ZWVuIDEgYW5kIGZvbGlvX25yX3BhZ2VzKCksIHdlIGhhdmUgdG8gY29uc2lkZXIgdHdv IAo+Pj4+IGlzc3VlczoKPj4+PiAxLiBIb3cgdG8gc2tpcCBQVEUgY2hlY2tzIGluc2lkZSBwYWdl X3ZtYV9tYXBwZWRfd2FsayBmb3IgZW50cmllcyB0aGF0Cj4+Pj4gd2VyZSBhbHJlYWR5IGhhbmRs ZWQgaW4gdGhlIHByZXZpb3VzIGJhdGNoOwo+Pj4KPj4+IFRoZXkgYXJlIGNsZWFyZWQgaWYgd2Ug cmVhY2ggdGhhdCBwb2ludC4gU28gdGhlIHB0ZV9ub25lKCkgY2hlY2tzIHdpbGwKPj4+IHNpbXBs eSBza2lwIHRoZW0/Cj4+Pgo+Pj4+IDIuIEhvdyB0byBicmVhayB0aGUgaXRlcmF0aW9uIHdoZW4g dGhpcyBiYXRjaCBoYXMgYXJyaXZlZCBhdCB0aGUgZW5kLgo+Pj4KPj4+IHBhZ2Vfdm1hX21hcHBl ZF93YWxrKCkgc2hvdWxkIGJlIGRvaW5nIHRoYXQ/Cj4+Cj4+IEl0IHNlZW1zIHlvdSBtaWdodCBo YXZlIG1pc3NlZCB0aGUgcGFydCBpbiBteSByZXBseSB0aGF0IHNheXM6Cj4+ICJPZiBjb3Vyc2Us IHdlIGNvdWxkIGF2b2lkIGJvdGgsIGJ1dCB0aGF0IHdvdWxkIG1lYW4gcGVyZm9ybWluZyAKPj4g dW5uZWNlc3NhcnkKPj4gY2hlY2tzIGluc2lkZSBwYWdlX3ZtYV9tYXBwZWRfd2FsaygpLiIKPiAg PiA+IFRoYXTigJlzIHRydWUgZm9yIGJvdGguIEJ1dCBJ4oCZbSB3b25kZXJpbmcgd2h5IHdl4oCZ cmUgc3RpbGwgZG9pbmcgdGhlIAo+IGNoZWNrLAo+PiBldmVuIHdoZW4gd2XigJlyZSBmYWlybHkg c3VyZSB0aGV54oCZdmUgYWxyZWFkeSBiZWVuIGNsZWFyZWQgb3Igd2XigJl2ZSByZWFjaGVkCj4+ IHRoZSBlbmQgOi0pCj4gCj4gOikKPiAKPj4KPj4gU29tZWhvdywgSSBmZWVsIHdlIGNvdWxkIGNv bWJpbmUgeW91ciBjbGVhbnVwIGNvZGXigJR3aGljaCBoYW5kbGVzIGEgYmF0Y2gKPj4gc2l6ZSBv ZiAibnIiIGJldHdlZW4gMSBhbmQgbnJfcGFnZXPigJR3aXRoIHRoZQo+PiAiaWYgKG5yX3BhZ2Vz ID09IGZvbGlvX25yX3BhZ2VzKGZvbGlvKSkgZ290byB3YWxrX2RvbmUiIGNoZWNrLgo+IAo+IFll YWgsIHRoYXQncyB3aGF0IEkgd2FzIHN1Z2dlc3RpbmcuIEl0IHdvdWxkIGhhdmUgdG8gYmUgcGFy dCBvZiB0aGUgCj4gY2xlYW51cCBJIHRoaW5rLgo+IAo+IEknbSBzdGlsbCB3b25kZXJpbmcgaWYg dGhlcmUgaXMgYSBjYXNlIHdoZXJlCj4gCj4gaWYgKG5yX3BhZ2VzID09IGZvbGlvX25yX3BhZ2Vz KGZvbGlvKSkKPiAgwqDCoMKgwqBnb3RvIHdhbGtfZG9uZTsKPiAKPiB3b3VsZCBiZSB3cm9uZyB3 aGVuIGRlYWxpbmcgd2l0aCBzbWFsbCBmb2xpb3MuCgpXZSBjYW4gbWFrZSB0aGUgY2hlY2sgbW9y ZSBleHBsaWNpdCB0byBhdm9pZCBhbnkgZnV0dXJlIHRyb3VibGUgOykKCmlmIChucl9wYWdlcyA+ IDEgJiYgbnJfcGFnZXMgPT0gZm9saW9fbnJfcGFnZXMoZm9saW8pKQogICAgIGdvdG8gd2Fsa19k b25lOwoKSXQgc2hvdWxkIGJlIHNhZmUgZm9yIHNtYWxsIGZvbGlvcy4KClRoYW5rcywKTGFuY2UK Cj4gCj4+IEluIHByYWN0aWNlLCB0aGlzIHdvdWxkIGxldCB1cyBza2lwIGFsbW9zdCBhbGwgdW5u ZWNlc3NhcnkgY2hlY2tzLAo+PiBleGNlcHQgZm9yIGEgZmV3IHJhcmUgY29ybmVyIGNhc2VzLgo+ Pgo+PiBGb3IgdGhvc2UgY29ybmVyIGNhc2VzIHdoZXJlICJuciIgdHJ1bHkgZmFsbHMgYmV0d2Vl biAxIGFuZCBucl9wYWdlcywKPj4gd2UgY2FuIGp1c3QgbGVhdmUgdGhlbSBhcy1pc+KAlHBlcmZv cm1pbmcgdGhlIHJlZHVuZGFudCBjaGVjayBpbnNpZGUKPj4gcGFnZV92bWFfbWFwcGVkX3dhbGso KS4KPiAKPiBJIG1lYW4sIGJhdGNoaW5nIG1hcGNvdW50K3JlZmNvdW50IHVwZGF0ZXMgZXRjLiBp cyBhbHdheXMgYSB3aW4uIElmIHdlIAo+IGVuZCB1cCBkb2luZyBzb21lIHVubmVjZXNzYXJ5IHB0 ZV9ub25lKCkgY2hlY2tzLCB0aGF0IG1pZ2h0IGJlIAo+IHN1Ym9wdGltYWwgYnV0IG1vc3RseSBu b2lzZSBpbiBjb250cmFzdCB0byB0aGUgb3RoZXIgc3R1ZmYgd2Ugd2lsbCAKPiBvcHRpbWl6ZSBv dXQgOikKPiAKPiBBZ3JlZWQgdGhhdCBpZiB3ZSBjYW4gZWFzaWx5IGF2b2lkIHRoZXNlIHB0ZV9u b25lKCkgY2hlY2tzLCB3ZSBzaG91bGQgZG8gCj4gdGhhdC4gT3B0aW1pemluZyB0aGF0IGZvciAi bnJfcGFnZXMgPT0gZm9saW9fbnJfcGFnZXMoZm9saW8pIiBtYWtlcyBzZW5zZS4KPiAKCgpfX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1yaXNjdiBt YWlsaW5nIGxpc3QKbGludXgtcmlzY3ZAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMu aW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LXJpc2N2Cg==