From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id n/ytHoTJ2mOFeScAWB0awg (envelope-from ) for ; Wed, 01 Feb 2023 15:20:20 -0500 Received: by simark.ca (Postfix, from userid 112) id 7008C1E128; Wed, 1 Feb 2023 15:20:20 -0500 (EST) Authentication-Results: simark.ca; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.a=rsa-sha256 header.s=default header.b=qhCz0fmG; dkim-atps=neutral X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-9.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,NICE_REPLY_A, RCVD_IN_DNSWL_HI,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 246131E112 for ; Wed, 1 Feb 2023 15:20:20 -0500 (EST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id A8B0C3858438 for ; Wed, 1 Feb 2023 20:20:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A8B0C3858438 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1675282819; bh=3pFfWGOx5CoRCnmmVV2L7gT6Zmo1ixiQ7NB4c0HhLZo=; h=Date:Subject:To:Cc:References:In-Reply-To:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=qhCz0fmGVLprXG9x3C+PsySOD0JOGlcfikTdPnJbeaqml/ieRK00Yai8LdKKjwRew pPnBi5hjRFbTldeOmmYDYqSLoDOoiFJt1IArLh7XjW3vCIByksX5VOmTEV6zhxtezR SORcgWUeQQZJJDnetW2EHueTJU7t2FZch29c9loI= Received: from simark.ca (simark.ca [158.69.221.121]) by sourceware.org (Postfix) with ESMTPS id 55AEF3858D37 for ; Wed, 1 Feb 2023 20:20:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 55AEF3858D37 Received: from [10.0.0.11] (unknown [217.28.27.60]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by simark.ca (Postfix) with ESMTPSA id C756C1E112; Wed, 1 Feb 2023 15:20:00 -0500 (EST) Message-ID: <70edf893-10e4-f55d-dd2d-c57747e01def@simark.ca> Date: Wed, 1 Feb 2023 15:20:00 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH v3 7/8] gdb/aarch64: Detect vector length changes when debugging remotely Content-Language: en-US To: Andrew Burgess , Thiago Jung Bauermann via Gdb-patches Cc: Thiago Jung Bauermann References: <20230130044518.3322695-1-thiago.bauermann@linaro.org> <20230130044518.3322695-8-thiago.bauermann@linaro.org> <878rhhtnis.fsf@redhat.com> In-Reply-To: <878rhhtnis.fsf@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Simon Marchi via Gdb-patches Reply-To: Simon Marchi Errors-To: gdb-patches-bounces+public-inbox=simark.ca@sourceware.org Sender: "Gdb-patches" > I guess the point I'm driving towards is that maybe instead of a new > gdbarch method we should add something like gdbarch_from_tdesc into > arch-utils.c (like we have gdbarch_from_bfd and gdbarch_find_by_info), > which just does a lookup from tdesc. One thing I would like to add: I presume that this process (gdbarch_find_by_info) is somewhat expensive. Is there an easy way to short-circuit things earlier? Maybe if we detect that a thread has the same target desc id as before, we can avoid recomputing the gdbarch? Or, we can cache the gdbarch in the remote_target. The remote_target::m_tdescs would hold both the target desc and corresponding gdbarch as values, instead of just the target desc. Actually, maybe the remote target wouldn't need to hold the target_desc at all, once it has the gdbarch. Other than maybe for lifetime reasons, which are discussed with the previous patch. Simon