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[156.34.55.100]) by smtp.gmail.com with ESMTPSA id f6sm1303617qkk.79.2019.06.06.11.44.46 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 06 Jun 2019 11:44:46 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1hYxNV-0008IT-Km; Thu, 06 Jun 2019 15:44:45 -0300 From: Jason Gunthorpe To: Jerome Glisse , Ralph Campbell , John Hubbard , Felix.Kuehling@amd.com Subject: [PATCH v2 hmm 05/11] mm/hmm: Remove duplicate condition test before wait_event_timeout Date: Thu, 6 Jun 2019 15:44:32 -0300 Message-Id: <20190606184438.31646-6-jgg@ziepe.ca> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190606184438.31646-1-jgg@ziepe.ca> References: <20190606184438.31646-1-jgg@ziepe.ca> MIME-Version: 1.0 X-Mailman-Approved-At: Fri, 07 Jun 2019 07:43:40 +0000 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=i7+8VVGKVPXEVnSFQY2/eN+heRnF32oClEuR9RZcz4c=; b=awv3zzYYkAzknK7/NkCAiHR5B250y04djNp+WoYpexe7Uej2IPZ5cqDxrJR0439HDp Ip+tkYncoM6synNyttQstYPfXOCfvqJ+MFaPA020vji6f3V+ijeewe00T5WLlGVbBkip ta/ZcbdijmmX7p+PqFRh9FOoQWxBygNZCZjmbhPstNfn/mX4xsgnW1BaTUSYo/a8jPup YkMIRPOwMicKl54A6Y5BoXPtSil+jxKqN6rTDrLm8CETdgRy4WQzp8exudHeoEcxgA4t JqZxvdcH0B1B5+3aq+YyPAmAifoH1FgyXvEu+EF0wwHDyoaCdNCX+I1ObXgN34um9W9p meJg== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrea Arcangeli , linux-rdma@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-mm@kvack.org, Jason Gunthorpe , dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Jason Gunthorpe The wait_event_timeout macro already tests the condition as its first action, so there is no reason to open code another version of this, all that does is skip the might_sleep() debugging in common cases, which is not helpful. Further, based on prior patches, we can no simplify the required condition test: - If range is valid memory then so is range->hmm - If hmm_release() has run then range->valid is set to false at the same time as dead, so no reason to check both. - A valid hmm has a valid hmm->mm. Also, add the READ_ONCE for range->valid as there is no lock held here. Signed-off-by: Jason Gunthorpe Reviewed-by: Jérôme Glisse Reviewed-by: Ralph Campbell Reviewed-by: Ira Weiny --- include/linux/hmm.h | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 4ee3acabe5ed22..2ab35b40992b24 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -218,17 +218,9 @@ static inline unsigned long hmm_range_page_size(const struct hmm_range *range) static inline bool hmm_range_wait_until_valid(struct hmm_range *range, unsigned long timeout) { - /* Check if mm is dead ? */ - if (range->hmm == NULL || range->hmm->dead || range->hmm->mm == NULL) { - range->valid = false; - return false; - } - if (range->valid) - return true; - wait_event_timeout(range->hmm->wq, range->valid || range->hmm->dead, + wait_event_timeout(range->hmm->wq, range->valid, msecs_to_jiffies(timeout)); - /* Return current valid status just in case we get lucky */ - return range->valid; + return READ_ONCE(range->valid); } /*