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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8537EB64D7 for ; Tue, 20 Jun 2023 18:08:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229988AbjFTSIM (ORCPT ); Tue, 20 Jun 2023 14:08:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229900AbjFTSIK (ORCPT ); Tue, 20 Jun 2023 14:08:10 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97AD5E55 for ; Tue, 20 Jun 2023 11:08:07 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-666ecb21f86so3879494b3a.3 for ; Tue, 20 Jun 2023 11:08:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687284487; x=1689876487; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to; bh=iiaacy8dR/Z7cvZSosFFtefecDI/FL+fwVPq6hWPcAw=; b=XHHKTJmWHb7JZ9BreGD02oW0fUfN69x7Hg0t7ITggQQ/lyQfGdx4/avcaWYGkI/W1w Pd+8kYMuXjrOqvH94nc3W02M5Ye9RLintoNCYOJUvXRxFZisbcNy7PmwheSvuiurSGt/ GpccDg76zoSf7ut7hXRYVdILlPWqv7JG84NHgeTwRruVBd5Mxq2EcIIsLBEl8SX0pqXN KLfb2FYkom2piH+kUjoSd9q1QmmPYD58LZOiMibJPhqSL+CsNC6ff+wFMdKJd2NJP23k T1ijoDYn1wH/h46Bqg+AS8K9dAWTrygVj6Lm3mJEX6hVYD23PZIw2DElhIZZF5CiZ1Kc vVgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687284487; x=1689876487; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:message-id:subject:cc:to:from:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=iiaacy8dR/Z7cvZSosFFtefecDI/FL+fwVPq6hWPcAw=; b=WmEEJqcJhX7uaft4YPy8Mo/z+c8mXTZSG/Issg6xBq8aG6zZaAyLFSSX119Lvl0Q0P ybCXmERV2rDGUB31qJkZlAJvdfZ5Ck3KJTNoIpopWv8ahU3aD1nGxvR0PHE+mI+7r2yZ rV9hieB+hV28aWbR5PGk0uznc5C9hV2BeS52IUE6sE7BtlCVO2zrBViUZeURnKUQGEB5 WNjKO0F+cbRIoE2JmlGv6IVCn1lZLTHM/49clln+9W91tYniX+Irnfegwgu/SVPaPQzG aoIxfM8LHtgAy+keG0+RS3WAdFTV2QaD7XRSyq5t/jpCuMsO/z+MUoK3EwWuWcGg9Sm4 i5WQ== X-Gm-Message-State: AC+VfDz/QxUdyLVncLxXTOv1OFrQ4lgsjbcjf8d+66/0vbEl0cvdB4Un tfgPmNRL6mLKTUltboYkdmI= X-Google-Smtp-Source: ACHHUZ6wJyE9uAHtsdE5qeiyzXecN6CaQmbaVvxhTL7kVp9n6WCVdxURW/S2LOCWBFbBUP2h7be7Ug== X-Received: by 2002:a05:6a00:991:b0:662:4041:30ba with SMTP id u17-20020a056a00099100b00662404130bamr18575102pfg.0.1687284486766; Tue, 20 Jun 2023 11:08:06 -0700 (PDT) Received: from sumitra.com ([106.207.162.67]) by smtp.gmail.com with ESMTPSA id t2-20020a62ea02000000b0064cca73d911sm1591371pfh.103.2023.06.20.11.08.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Jun 2023 11:08:06 -0700 (PDT) Date: Tue, 20 Jun 2023 11:07:59 -0700 From: Sumitra Sharma To: Ira Weiny Cc: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Thomas =?iso-8859-1?Q?Hellstr=F6m_=28Intel=29?= , Fabio , Deepak R Varma , Sumitra Sharma Subject: Re: [PATCH v2] drm/i915: Replace kmap() with kmap_local_page() Message-ID: <20230620180759.GA419158@sumitra.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6491a85a37cc8_28e729425@iweiny-mobl.notmuch> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 20, 2023 at 06:23:38AM -0700, Ira Weiny wrote: > Sumitra Sharma wrote: > > On Sun, Jun 18, 2023 at 11:11:08AM -0700, Ira Weiny wrote: > > > Sumitra Sharma wrote: > > > > kmap() has been deprecated in favor of the kmap_local_page() > > > > due to high cost, restricted mapping space, the overhead of a > > > > global lock for synchronization, and making the process sleep > > > > in the absence of free slots. > > > > > > > > kmap_local_page() is faster than kmap() and offers thread-local > > > > and CPU-local mappings, take pagefaults in a local kmap region > > > > and preserves preemption by saving the mappings of outgoing tasks > > > > and restoring those of the incoming one during a context switch. > > > > > > > > The mapping is kept thread local in the function > > > > “i915_vma_coredump_create” in i915_gpu_error.c > > > > > > > > Therefore, replace kmap() with kmap_local_page(). > > > > > > > > Suggested-by: Ira Weiny > > > > > > > > > > NIT: No need for the line break between Suggested-by and your signed off line. > > > > > > > Hi Ira, > > > > What does NIT stand for? > > Shorthand for 'nitpicking'. > > "giving too much attention to details that are not important, especially > as a way of criticizing: " > > - https://dictionary.cambridge.org/dictionary/english/nitpicking > > Via email this is a way for authors of an email to indicate something is > technically wrong but while nicely acknowledging that it is not very > significant and could be seen as overly critical. > > For this particular comment I'm showing something to pay attention to next > time but that was not a big deal this time around. > Hi Ira, Thank for your explanation on NIT. > > > > Thank you. I will take care about the line breaks. > > > > > > Signed-off-by: Sumitra Sharma > > > > --- > > > > > > > > Changes in v2: > > > > - Replace kmap() with kmap_local_page(). > > > > > > Generally it is customary to attribute a change like this to those who > > > suggested it in a V1 review. > > > > > > For example: > > > > > > - Tvrtko/Thomas: Use kmap_local_page() instead of page_address() > > > > > > Also I don't see Thomas on the new email list. Since he took the time to > > > review V1 he might want to check this version out. I've added him to the > > > 'To:' list. > > > > > > Also a link to V1 is nice. B4 formats it like this: > > > > > > - Link to v1: https://lore.kernel.org/all/20230614123556.GA381200@sumitra.com/ > > > > > > All that said the code looks good to me. So with the above changes. > > > > > > Reviewed-by: Ira Weiny > > > > > > > I have noted down the points mentioned above. Thank you again. > > > > I am not supposed to create another version of this patch for > > adding the above mentions, as you and Thomas both gave this patch > > a reviewed-by tag. Right? > > > > Based on this response[*] from Tvrtko I think this version can move > through without a v3. Okay! Thanks & regards Sumitra > > Thanks! > Ira > > [*] https://lore.kernel.org/all/bcb0a1d2-cd4d-a56f-1ee6-7ccfdd2f7b38@linux.intel.com/ > > > Thanks all! I'll just re-send the patch for our CI, since it didn't get > picked up automatically (stuck in moderation perhaps), with all r-b tags > added and extra line space removed and merge it if results will be green. > > Regards, > > Tvrtko > > > > > > > Thanks & regards > > Sumitra > > > > PS: I am new to the open source vocabulary terms. > > > > > > - Change commit subject and message. > > > > > > > > drivers/gpu/drm/i915/i915_gpu_error.c | 4 ++-- > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c > > > > index f020c0086fbc..bc41500eedf5 100644 > > > > --- a/drivers/gpu/drm/i915/i915_gpu_error.c > > > > +++ b/drivers/gpu/drm/i915/i915_gpu_error.c > > > > @@ -1164,9 +1164,9 @@ i915_vma_coredump_create(const struct intel_gt *gt, > > > > > > > > drm_clflush_pages(&page, 1); > > > > > > > > - s = kmap(page); > > > > + s = kmap_local_page(page); > > > > ret = compress_page(compress, s, dst, false); > > > > - kunmap(page); > > > > + kunmap_local(s); > > > > > > > > drm_clflush_pages(&page, 1); > > > > > > > > -- > > > > 2.25.1 > > > > > > > > > > > >