Date: Sun, 30 May 2010 18:06:22 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Dmitry Marakasov <amdmi3@amdmi3.ru> Cc: freebsd-current@freebsd.org, freebsd-stable@freebsd.org Subject: Re: need better POSIX semaphore support Message-ID: <20100530150622.GJ83316@deviant.kiev.zoral.com.ua> In-Reply-To: <20100530143034.GH43302@hades.panopticon> References: <20100530143034.GH43302@hades.panopticon>
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--aJd1ttTPPR7r8b0Q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, May 30, 2010 at 06:30:35PM +0400, Dmitry Marakasov wrote: > Hi! >=20 > Not long ago, POSIX semaphores support was enabled by default as it's > becoming more widely used, by e.g. firefox. However, the support > for these is still incomplete: we only have systemwide limit of 30 > semaphores, and that doesn't seem to be configurable neither online with > sysctl, nor at boottime from loader.conf. I only was able to raise > semaphore count by changing SEM_MAX in kernel sources. >=20 > The real appliaction which needs more semaphores is lightspark > (graphics/lightspark-devel) flash plugin - it uses ~40 sems for simple > clips and ~250 for something like youtube videos. >=20 > Until there more apps that require proper semaphore support, I guess > we need to improve it asap. Given the amount of memory used by ksem, > the least can be done is SEM_MAX bumped up to 5120 or so for > non-embedded kernels. 5120 semaphores require just 644k of kernel > memory (judging by vmstat), and is "ought to be enough for anybody". > Another good thing would be to make it configurable at boot-time > or even better in runtime. HEAD contains different implementation. Apparently, it did not made into stable/8 yet, so it will not appear in the 8.1. Try this, I could try to squeeze it into 8.1. diff --git a/sys/kern/posix4_mib.c b/sys/kern/posix4_mib.c index 5242b31..41e28da 100644 --- a/sys/kern/posix4_mib.c +++ b/sys/kern/posix4_mib.c @@ -57,6 +57,9 @@ SYSCTL_DECL(_p1003_1b); #define P1B_SYSCTL(num, name) \ SYSCTL_INT(_p1003_1b, num, \ name, CTLFLAG_RD, facility + num - 1, 0, ""); +#define P1B_SYSCTL_RW(num, name) \ +SYSCTL_INT(_p1003_1b, num, \ + name, CTLFLAG_RW, facility + num - 1, 0, ""); =20 #else =20 @@ -65,6 +68,9 @@ SYSCTL_DECL(_kern_p1003_1b); #define P1B_SYSCTL(num, name) \ SYSCTL_INT(_kern_p1003_1b, OID_AUTO, \ name, CTLFLAG_RD, facility + num - 1, 0, ""); +#define P1B_SYSCTL_RW(num, name) \ +SYSCTL_INT(_kern_p1003_1b, OID_AUTO, \ + name, CTLFLAG_RW, facility + num - 1, 0, ""); SYSCTL_NODE(_kern, OID_AUTO, p1003_1b, CTLFLAG_RW, 0, "P1003.1B"); =20 #endif @@ -91,7 +97,7 @@ P1B_SYSCTL(CTL_P1003_1B_DELAYTIMER_MAX, delaytimer_max); P1B_SYSCTL(CTL_P1003_1B_MQ_OPEN_MAX, mq_open_max); P1B_SYSCTL(CTL_P1003_1B_PAGESIZE, pagesize); P1B_SYSCTL(CTL_P1003_1B_RTSIG_MAX, rtsig_max); -P1B_SYSCTL(CTL_P1003_1B_SEM_NSEMS_MAX, sem_nsems_max); +P1B_SYSCTL_RW(CTL_P1003_1B_SEM_NSEMS_MAX, sem_nsems_max); P1B_SYSCTL(CTL_P1003_1B_SEM_VALUE_MAX, sem_value_max); P1B_SYSCTL(CTL_P1003_1B_SIGQUEUE_MAX, sigqueue_max); P1B_SYSCTL(CTL_P1003_1B_TIMER_MAX, timer_max); --aJd1ttTPPR7r8b0Q Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (FreeBSD) iEYEARECAAYFAkwCfu4ACgkQC3+MBN1Mb4inuACgwDhkHfAox2Km+EKeQkUkYQeM QusAmgLSXQKMzuGanmQD8yhBUlqcvDN3 =Irt5 -----END PGP SIGNATURE----- --aJd1ttTPPR7r8b0Q--
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