From mboxrd@z Thu Jan 1 00:00:00 1970 From: jarkko.sakkinen@linux.intel.com (Jarkko Sakkinen) Date: Wed, 16 May 2018 17:10:35 +0300 Subject: [PATCH v4 1/2] tpm: reduce poll sleep time in tpm_transmit() In-Reply-To: <20180516055125.5685-2-nayna@linux.vnet.ibm.com> References: <20180516055125.5685-1-nayna@linux.vnet.ibm.com> <20180516055125.5685-2-nayna@linux.vnet.ibm.com> Message-ID: <20180516141035.GA10304@linux.intel.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On Wed, May 16, 2018 at 01:51:24AM -0400, Nayna Jain wrote: > tpm_try_transmit currently checks TPM status every 5 msecs between > send and recv. It does so in a loop for the maximum timeout as defined > in the TPM Interface Specification. However, the TPM may return before > 5 msecs. Thus the polling interval for each iteration can be reduced, > which improves overall performance. This patch changes the polling sleep > time from 5 msecs to 1 msec. > > Additionally, this patch renames TPM_POLL_SLEEP to TPM_TIMEOUT_POLL and > moves it to tpm.h as an enum value. > > After this change, performance on a system[1] with a TPM 1.2 with an 8 byte > burstcount for 1000 extends improved from ~14 sec to ~10.7 sec. > > [1] All tests are performed on an x86 based, locked down, single purpose > closed system. It has Infineon TPM 1.2 using LPC Bus. Already applied previous version of this. /Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html